Particles 2008 - nanoparticles.org

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Particles 2008
Particle Synthesis, Characterization, and
Particle-Based Advanced Materials
10-13 May 2008
Wyndham Resort Hotel, Orlando, Florida
Courtesy Hans-Gerd Boyen
(left) Courtesy David Pine and (right) adapted from Invitrogen QDot Art
2
TABLE OF CONTENTS
Sponsors
4
Corporate Sponso
5
International Organizing Committee
6
Exhibitors
7
General Program Schedule
12
Maps of Meeting Spaces
14
Technical Program – Oral Sessions
15
Technical Program – Poster Sessions
31
Abstracts of Oral Program
37
Abstracts of Poster Program
231
Author/Speaker/Presenter Index
305
Preregistered Conferee List
311
Upcoming Meetings
351
Notes
353
3
Sponsors
Division of Colloid and Surface Chemistry
of the
American Chemical Society
Particles Conference
4
Corporate Sponsor
5
International Organizing Committee
L. Abrams (USA)
P. Alivasatos (USA)
R. Aveyard (UK)
V. Babak (Russia)
J. Brinker (USA)
B. Cabane (France)
A. Couzis (USA)
S.S. Feng (Singapore)
M. El-Sayed (USA)
N. Garti (Israel)
K. Johnston (USA)
E.W. Kaler (USA)
H. Kawaguchi (Japan)
J. H. Kim (Korea)
H.S. (Frank) Koo (Taiwan)
S. Magdassi (Israel)
S. Margel (Israel)
B. Moudgil (USA)
P. Mulvaney (Australia)
M.C. Roco (USA)
J.-L. Salager (Venezuela)
J. Sjöblom (Norway)
S. Simoes (Portugal)
P. T. Spicer (USA)
S. Svenson (USA)
J. Texter (USA), General Chair
N. Vail (USA)
R. Ziolo (USA)
6
Exhibitors
Agilent Technologies
900 South Taft Avenue
Loveland, CO 80537
970 679 3128
Fax: 970 679 5783
http://www.agilent.com/chem/particles/
Beckman Coulter
11800 SW 147th Avenue
Miami, FL 33196
305 380 3907
Fax: 305 883 6877
http://beckmancoulter.com
Brookhaven Instruments Corporation
750 Blue Point Road
Holtsville, NY 11742
631 758 3200, x 101
Fax: 631 758 3255
http://bic.com
Bühler AG
Gupfenstrasse 5
9240 Uzwil
SWITZERLAND
+41 71 955 26 27
Fax: +41 71 955 38 73
http://buhlergroup.com
7
Exhibitors (continued)
CPS Instruments, Inc.
311 Society Place
Newtown, PA 18940
215 860 4540
Fax: 215 860 4543
http://cpsinstruments.com
CytoViva, Inc.
300 North Dean Road
PMB 157 – Suite 5
Auburn, AL 36830
334 737 3133
Fax: 334 749 2627
http://www.cytoviva.com
IBU-tec advanced materials GmbH
Hainweg 9-10
D-99425 Weimar
GERMANY
+49 3643 86490
Fax: +49 3643 864930
http://www.ibu-tec.de/index.php?p=homepage
Inotech Biosystems International
15713 Crabbs Branch Way
Derwood, MD 20855
301 670 2850
Fax: 301 670 2859
http://www.ibu-tec.de/index.php?p=homepage
8
LUM Corporation
16201 Dodd Street
Volente, TX 78641
512 383 5286
http://www.lum-gmbh.com/pages/products.htm
Malvern Instruments
117 Flanders Road
Westborough, MA 01581
508 768 6400, x 421
Fax: 508 768 6403
http://www.malvern.co.uk
Microtrac Inc.
12501-A 62nd Street North
Largo, FL 33773
727 507 9770, x 13
Fax: 727 507 9774
http://www.microtrac.com
NanoImaging Services, Inc.
10931 North Torrey Pines Road, Suite 108
San Diego, CA 92037
888 675 8261, x 102
http://www.nanoimagingservices.com/
9
NanoSight Limited
2 Centre One
Lysander Way
Salisbury, SP4 6BU, Wiltshire
UNITED KINGDOM
+44 1 722 349439
Fax: +44 1 722 329640
http://www.nanosight.co.uk/
Particle Sizing Systems
8203 Kristel Circle
Port Richey, FL 34668
727 846 0866
Fax: 727 846 0865
http://www.pssnicomp.com
Q-Sense Inc.
808 Landmark Drive, Suite 124
Glen Burnie, MD 21061
410 768 9812
Fax: 410 768 9816
http://www.q-sense.com
Quantachrome Instruments
1900 Corporate Drive
Boynton Beach, FL 33426
561 731 4999
http://www.quantachrome.com
10
Spectra Services, Inc.
6359 Dean Parkway
Ontario, NY 14519
585 265 4320
http://www.spectraservices.com
Surface Measurement Systems
2125 28th Street SW, Suite 1
Allentown, PA 18103
610 462 1123
http://www.smsuk.co.uk
TSI Incorporated
500 Cardigan Road
Shoreview, MN 55126
651 490 4067
http://www.tsi.com
University of Central Florida
12424 Research Parkway, Suite 400
Orlando, FL 32826
407 882 1189
Fax: 407 882 2819
http://www.nanoscience.ucf.edu/index.php
11
General Program Schedule
Registration – Registration is outside of Citrus Ballroom in Prefunction Area
Saturday, May 10
(1800 – 1930) – Opening Informal Reception & Exhibition (Citrus Ballroom)
Sunday, May 11
(0800 – 0850) - Plenary 1 (Citrus Ballroom)
(0900 – 1230) – Technical Sessions: A1(Magnolia), A2 (Oleander B), B1
(Oleander A), C1 (Azaela), D1 (Marathon-Cedar), E1 (Biscayne-Siesta), and F1
(Jasmine)
(1200 – 1400) – Luncheon/Exhibition (Citrus Ballroom)
(1400 – 1730) – Technical Sessions: A3 (Magnolia), G1 (Oleander B), H1
(Oleander A), I1 (Azaela), J1 (Marathon-Cedar), K1 (Biscayne-Siesta), and F2
(Jasmine)
(1800 – 1930) – Poster Session (P1)/Reception/Exhibition (Citrus Ballroom)
Monday, May 12
12
General Program Schedule (continued)
Monday, May 12 (continued)
(0900 – 1230) – Technical Sessions: A4 (Magnolia), G2 (Oleander B), B2
(Oleander A), C2 (Azaela), D2 (Marathon-Cedar), E2 (Biscayne-Siesta), and F3
(Jasmine)
(1400 – 1730) – Technical Sessions: A5 (Magnolia), G3 (Oleander B), H2
(Oleander A), C3 (Azaela), J2 (Marathon-Cedar), L1 (Biscayne-Siesta), and F4
(Jasmine)
(1800 – 1930) – Poster Session (P2)/Reception/Exhibition (Citrus Ballroom)
Tuesday, May 13
(0900 – 1230) – Technical Sessions: A6 (Magnolia), G4 (Oleander B), B3
(Oleander A), M1 (Azaela), D3 (Marathon-Cedar), E3 (Biscayne-Siesta), and F5
(Jasmine)
(1400 – 1730) – Technical Sessions: A7 (Magnolia), A8 (Oleander B), H3
(Oleander A), C4 (Azaela), J3 (Marathon-Cedar), E4 (Biscayne-Siesta), and F6
(Jasmine)
Conference Ends
13
Maps of Meeting Spaces
Contiguous meeting spaces at Wyndham. Conference activities use the Floral Ballroom
on the left, the Citrus Ballroom (center) through the Biscayne-Siesta room in the Key
Rooms to the right. Registration is outside of the Citrus Ballroom (center).
The Citrus Ballroom is the venue for all three Plenary Lectures, the luncheons, and the
receptions. The Marathon-Cedar and Biscayne-Siesta room to the right are used for some
of the technical break-out sessions.
All four parts of he Floral Ballroom are used throughout.
14
Technical Program – Oral Sessions
Sunday Morning, May 11, 2008
Plenaey 1 (Sunday 0800-0850), Citrus Ballroom)
Session Chair: Jim Adair
0805 1. Plenary 1 - Christopher B. Murray; Building with artificial atoms: Routes to multifunctional nanocrystal based materials and devices
Session A1 (Sunday, 0900-1215, Magnolia) Advanced Particle Synthesis
Session Chair: Francesco Stellacci
0900
0935
0950
1015
1030
1055
1120
1145
1200
1215
2. Esko Kauppinen; Keynote - Carbon NanoBudTM – A novel nanomaterial:
Synthesis, structure, field emission and transport properties
3. Stefan Jaksch; Manipulation of films of nanoparticles
4. Sungmin Choi; Water redispersible single wall carbon nanotubes fabricated by in
situ polymerization of micelles
Break
5. Karl Coleman; Chemically modified single-walled carbon nanotubes: Synthesis
and application in polymer composites
6. Eiji Osawa; Monodisperse single-nano diamond particles
7. Giuseppe Compagnini; Synthesis and properties of nanoparticles and nanowires
by laser ablation in liquid environments
8. Ana Menéndez-Manjón; Metallic nanoparticles generated by ultra-short pulsed
laser ablation in liquid media
9. Sophie Giraud; Synthesis of iron containing nanopowders by laser pyrolysis for
biomedical applications
End of Session
Session A2 (Sunday, 0900-1200, Oleander B) Advanced Particle Synthesis
Session Chair: Moshe Narkis
0900 10. Markus Niederberger; Keynote - Metal oxide nanoparticle synthesis: From binary
metal to multi metal and doped metal oxides
0940 11. Lorette Sicard; Synthesis of manganese oxide nanocubes
0955 12. Ying Zheng; Synthesis of high purity hydroxyapatite nanopowders by the
surfactant-assisted and hydrothermal method
1010 Break
1030 13. Richard Brotzman; Keynote - Trends in nanomaterials synthesis and
applications
1100 14. Carole Sentein; Dispersion and stability of TiO2 nanoparticles synthesized by
laser pyrolysis in aqueous suspensions
1115 15. Jean-Yves Piquemal; An easy procedure for the preparation of ferromagnetic
cobalt nanorods via the polyol process: Towards the formation of permanent
magnets
1130 16. Tadafumi Adschiri; Supercritical hydrothermal synthesis of organic inorganic
hybrid nanocolloids
1200 End of Session
15
Technical Oral Program (continued)
Session B1 (Sunday, 0900-1205, Oleander A) Particle Encapsulation
Session Chair: Anil Kumar Anal
0900 17. Michael Pishko; Keynote - Encapsulation of drug nanoparticles in selfassembled macromolecular nanoshells
0930 18. Rachel M. Frazier; Microencapsulation of active nutraceutical ingredients for
controlled delivery
0945 19. Toshifumi Satoh; Encapsulation property of unimolecular nanocapsule based on
hyperbranched polymer
1010 Break
1030 20. Ying-Wu Luo; Nanoencapsulation via interfacially confined reversible addition
fragmentation transfer (RAFT) miniemulsion polymerization
1055 21. Marcel Böhmer; Synthesis of monodisperse particles and capsules by
submerged injet-printing
1110 22. Sílvia S. Guterres; Incorporation in polymeric nanocapsules improves the
antioxidant effect of melatonin against lipid peroxidation in mice brain and liver
1125 23. Dieter Trau; Reverse phase layer-by-layer polyelectrolyte self assembly
encapsulation of water soluble microparticular materials
1150 24. Emek Seyrek; Layer-by-layer assembly on gold nanoparticles
1205 End of Session
Session C1 (Sunday, 0900-1215, Azaela) Particle Arrays & Photonics
Session Chair: Cefe Lopez
0900 25. Alamgir Karim; Directed assembly with nanoparticle systems
0930 26. Takuya Harada; Formation of highly ordered anisotropic nanoparticle
superlattices by self-assembly on water surfaces
0945 27. Clemens Richert; Large DNA-based particles from oligonucleotide hybrids with
organic cores
1015 Break
1030 28. Eugene Zubarev; Synthesis and self-assembly of gold nanorods
1045 29. Jiyu Fang; Lipid tubules with birefringent cores and their ordered arrays
1115 30. Emanuela Tamburri; Arrays of carbon nanotubes coated by nanoparticles of
metals and metal-oxides
1145 31. Li Jia; Surface patterning using interfacial colloidal crystals
1215 End of Session
Session D1 (Sunday, 0900-1205, Marathon-Cedar) Particle Characterization
Session Chair: Helmut Coelfen
0900 32. Ian Morrison; Keynote - Nanopowder surface characterization
0940 33. Ren Xu; Zeta potential characterization of particles in suspension
0955 34. Bob Carr; Real-time, simultaneous analysis of nanoparticle size, zeta potential,
count, asymmetry and fluorescence in liquids
1010 Break
1030 35. Andrei Dukhin; Ultrasound for characterizing nano-colloids: Sizing, zeta
potential, rheology
1055 36. Miran Mozetic; Characterization of particle distribution and orientation in solid
media
1120 37. Ali Bumajdad; Highly stable suspensions of metal oxide nanoparticles
0955 38. Matthew McMahon; Orthogonal tracking microscopy for nanofabrication
research
1150 39. Arup Mukherjee; FT-IR and diffuse reflectance FT-IR for quantitative drug load
estimation in alginate nanocapsules with testosterone payload
1205 End of Session
16
Session E1 (Sunday, 0900-1205, Biscayne-Siesta) Particle Based Devices
Session Chair: Hans-Gerd Boyen
0900 40. Richard M. Laine; Keynote - Transparent, polycrystalline upconverting
nanoceramics: Towards 3-D displays
0930 41. Tanya Kosc; Particles on the beach: The dream of electronic paper
0955 42. Hyun-Ryool Woo; Modification of pigment surface with acrylic copolymers for
microcapsule-based electrophoretic display
1010 Break
1030 43. Alain Perez; Keynote - Low energy cluster beam deposition method to produce
functional nanostructures and high integration-density devices
1100 44. Lien-chung Hsu; Preparation of contamination free silver nanoparticle
suspensions for micro-interconnects by ink-jet printing
1125 45. Nancy Van Suetendael; A survey of nanolithographic techniques used to create
nanostructures
1140 46. Pei Lin Chen; Novel applications of colloidal lithography
1205 End of Session
Session F1 (Sunday, 0900-1220, Jasmine) Particle Based Advanced
Materials
Session Chair: Warren Ford
0900 47. Lennart Bergstrom; Keynote - Assembly of orientationally ordered
nanocrystalline films and superlattices
0930 48. Johan E. ten Elshof; Structural development of sol-gel derived hybrid colloids
for nanoporous materials and thin film membranes
0945 49. Jimmy Mills; Kinetic features of metal nanoparticle formation in polymer films
1010 Break
1030 50. Amit Singhal; Scalable solid state synthesis process for producing
nanostructured electrode materials
1045 51. J. Adin Mann, Jr.; A molecular dynamics study of the structure of nanoparticles
of platinum and alloys of platinum adsorbed onto carbon substrates of fuel cell
supported catalysts
1110 52. Hong Yang; Platinum-based alloy and intermetallic nanoparticles as fuel cell
catalysts
1135 53. Chuan-Jian Zhong; Multimetallic nanoparticles and nanotechnology in catalysis
1200 54. Huaming Yang; Novel preparation and photocatalytic property of WO3V2O5/TiO2 nanocomposites
1215 End of Session
Sunday Afternoon, May 11, 2008
Session A3 (Sunday, 1400-1710, Magnolia) Advanced Particle Synthesis
Session Chair: Ray Mackay
1400 55. Katharina Landfester; Keynote - Nanoparticles and nanocapsules obtained by
miniemulsion polymerization
1440 56. Warren Ford; Dispersion polymerization of cross-linked poly(2ethylhexylmethacrylate-co-chloromethylstyrene) in fluorinated solvents
1510 Break
1530 57. Mayashi Kunitake; Monodisperse polystyrene particles prepared by
polymerization in silica particle suspensions without surfactant
17
1600 58. Yvon Durant; Synthesis and characterization of targeted polymeric
nanoparticles for biomedical applications
1630 59. Moshe Narkis; Modification of porous PVC particles via polymerization ofsorbed
monomers in stabilizer-free aqueous dispersions
1700 60. Dmitri Vezenov; Facile synthesis of luminescent magnetic nano- and
microspheres: Embedding of quantum dots and magnetite nanoparticles in a
polymer matrix
1715 End of Session
Session G1 (Sunday, 1400-1725, Oleander B) Particle Based Diagnostics
Session Chair: Michael Giersig
1400 61. Francesco Stellacci; Keynote - The role of supramolecular Kang structure in
nanoparticle-cell interactions
1430 62. Kang Sun; Quantum dot encoded microbeads with magnetism and carboxyl
surfaces
1445 63. Chantal Paquet; Multifunctional nanostructured composite colloids prepared
using a miniemulsion approach
1500 64. Nitin Nitin; Oligonucleotide-coated metallic nanoparticles as a flexible platform
for molecular imaging agents
1515 Break
1530 65. Hedi Mattoussi; Quantum dot-bioconjugatees: Characterization and use for
sensing and live cell imaging
1555 66. Taeghwan Hyeon; Synthesis and biomedical applications of uniform-sized
nanoparticles
1610 67. Marc Porter; Design of gold nanoparticles for ultrasensitive biodiagnostics
using SERS
1635 68. Y. T Chen; In situ detection of cellular exocytosis with a single-walled carbon
nanotube field-effect transistors
1700 69. Wan Soo Yun; Electric detection of biomolecules by nanoparticle device
1725 End of Session
Session H1 (Sunday, 1400-1715, Oleander A) Particles In Drug and
Chemical Delivery
Session Chair: Giulio Paciotti
1400 70. Si-Shen Feng; Keynote - Nanomedicine: Nanoparticles of biodegradable
polymers for cancer treatment
1430 71. Justyna Frelachowska; Particle-stabilized emulsions: Skin Penetration studies
compared to classical emulsions
1445 72. Manny Perez; Dextran-coated cerium oxide nanoparticles with pH-dependent
antioxidant properties
1510 Break
1530 73. Krassimir Velikov; Colloidal delivery systems for micronutrients and
nutraceuticals
1555 74. Rein Ulijn; Enzyme-responsive polymer hydrogel particles for controlled release
1610 75. Hanna Mouaziz; Nanoparticles in diagnostic and therapeutic domain
1625 76. Victor S.-Y. Lin; Stimuli-responsive mesoporous nanoparticles for intracellular
controlled release and bioenergy applications
1650 77. Tao L. Lowe; Polysaccharide-based nanogels for sustained drug delivery
1715 End of Session
18
Session I1 (Sunday, 1400-1720, Azaela) Morphology Control in Particle
Synthesis
Session Chair: Ingo H. Leubner
1400 78. Luis Liz-Marzan; Keynote - Shaping Au nanoparticles: From seeds to
decahedrons - from rods to octahedrons
1430 79. Takasi Nisisako; Monodisperse anisotropic polymeric microparticles
synthesized using a microfluidic droplet generator
1455 80. Richard Tilley; Liquid phase syntesis of nanoparticles
1510 Break
1530 81. Helmut Coelfen; Keynote - Particle mediated crystallization
1600 82. Amane Jada; CaCO3 particle shapes as resulting from aggregation of
nanoparticles and control by polyelectrolytes
1625 83. Herve Dietsch; Surface-functionalized inorganic-organic multilayer particles:
Synthesis, science and applications
1640 84. Yuval Golan; Nanomaterials at interfaces: Wet chemical routes for size, shape
and orientation controlled nanoparticles
1705 85. Vanessa Prevot; Various layered double hydroxide morphologies obtained
through solvothermal synthesis directed by amino acids
1720 End of Session
Session J1 (Sunday, 1400-1725, Marathon-Cedar) Particle Surface
Modification
Session Chair: Kui Yu
1400 86. Atsushi Takahara; Keynote - Surface modification of silica nanopariticle and Siwafer through surface-initiated controlled radical polymerization
1430 87. Qiu Dai; Optical limiting studies of “necklace”-like gold nanoparticles/polymer
hybrids
1445 88. Brian Benicewicz; RAFT polymerization from nanoparticles
1510 Break
1530 89. Hidehiro Kamiya; Surface molecular structure and interaction design to control
dispersion behavior of nanoparticles in organic solvents
1555 90. Simon A. Biggs; Complex particle coatings from block copolymer micelle
multilayer films
1620 91. V. Prasad Shastri; Nanoparticles as tools for controlling cell function
1645 92. Robert Hoerr; Surface modification of polyisobutylene-based medical device
coatings using ElectroNanospray™
1710 93. Nguyen Thi Xuyen; Hydrolysis-induced immobilization of Pt(AcAc)2 on
polyimide nanofiber mat in the formation of Pt nanoparticles
1725 End of Session
Session K1 (Sunday, 1400-1700, Biscayne-Siesta) Environmental Impact &
Toxicology of Particulates
Session Chair: Adriana R. Pohlmann
1400 94. Prabir Dutta; Keynote - Biological activity of mineral fibers and carbon
particulates: Implications for nanoparticle toxicity and the role of surface
chemistry
1440 95. Nava Narkis; Particulate suspensions of Ettringite for removal of boron
compounds from aqueous solutions
1510 Break
1530 96. Paola Nativo; Controlling uptake and intracellular fate of surface modified
colloidal gold
1545 97. Daniel Clemans; Bactericidal activity of solvent-free nanofluids
19
1600 98. Marina A. Dobrovolskaia; Preclinical immunological characterization of
nanoparticles
1630 99.Christophe Goepfert; SAPHIR (European Project): Safe, integrated & controlled
production of high-tech multifunctional materials and their recycling
1645 100. Yvonne Williams; Localization of quantum dots within cell compartments is
dependent on the size of the particle and on the cell lineage
1700 End of Session
Session F2 (Sunday, 1400-1735, Jasmine) Particle Based Advanced
Materials
Session Chair: Jimmy Mills
1400 101. Lyudmila Bronstein; Functional magnetic nanoparticles as building blocks of
novel biomaterials
1430 102. Masura Matsuo; Structural change in carbon-polymer composites by
exothermic effects induced by electric fields
1500 103. Souad Ammar; Size dependent magnetic properties of polyol-made CoFe2O4
nanoparticles
1515 Break
1530 104. Mitch Winnik; Keynote - Polymer and inorganic nanoparticles intended for
bioassays
1605 105. Jean-Francois Berret; Controlled co-assembly of iron oxide nanoparticles and
polymers: Towards the generation of highly persistent superparamagnetic
nanorods
1620 106. Dale L. Huber; The role of surfactant interactions in the magnetic properties of
chemically synthesized nanoparticles and nanocomposites
1650 107. Virginia Bouzas; Physical properties of hybrid semiconductor-ferromagnet
nanostructures
1705 108. Mahendra K. Sunkara; Bulk production and modification of inorganic nanowires
for solar energy conversion and storage applications
1735 End of Session
Monday Morning, May 12, 2008
Plenary 2 (Monday 0800-0850), Citrus Ballroom)
Session Chair: Emmanuel Giannelis
0805 165. Plenary 2 - Vicki L. Colvin; How to generate and manipulate nanoparticles with
minimal biological impact
Session A4 (Monday, 0900-1210, Magnolia) Advanced Particle Synthesis
Session Chair: Heinrich Hofmann
0900 166. Clinton Ballinger; Keynote - Commericialization of semiconductor nanoparticles
0930 167. Rodion Belosludov; Ab initio description of the quantum dot with novel core
structure and their interaction with organic ligand
0945 168. Nicola Pinna; Photoluminescent rare-earth-based lamellar organic-inorganic
nanoparticles
1010 Break
1030 169. Fernand Fiévet; Keynote - Nucleation and growth of metals, oxides and
chalcogenides in polyols: Control of size and shape of the particles
1100 170. Qing Song; Synthesis, characterization and bio-templated assembly of highly
photoluminescent water soluble quantum dots
1115 171. Hongwei Duan; New approaches towards water-soluble and fluorescent metal
nanoclusters
20
1140 172. Joydeep Dutta; Enhanced visible light photocatalysis by tailoring defects in zinc
oxide crystals
1155 173. David Díaz; Metallic nanoparticles synthesized under soft reaction conditions
with high yields
1210 End of Session
Session G2 (Monday, 0900-1225, Oleander B) Particle Based Diagnostics
Session Chair: Wolfgang Parak
0900 174. Michael Giersig; Keynote - Nanomaterials and their application in biomedicine
0930 175. Kristien Bonroy; Functionalized inorganic nanostructures for biomedical
applications
0945 176. Robert H. Pelton; Microgel-based inks for paper-supported biosensing
applications
1010 Break
1030 177. James Adair; Calcium phosphate nanocolloids for bioimaging and drug delivery
1055 178. Gan-Moog Chow; NIR activated upconversion nanoparticles with visible
emission for sensing and imaging
1120 179. Silvia H. De Paoli Lacerda; Influence of gold nanoparticles on the attachment of
osteoblast cells to substrates
1135 180. Xiaohu Gao; Simultaneous imaging and delivery of siRNA with quantum dots
1200 181. Qun Huo; Gold nanoparticle probe-based immunoassay for cancer biomarker
detection
1225 End of Session
Session B2 (Monday, 0900-1210, Oleander A) Particle Encapsulation
Session Chair: Thomas Scheibel;
0900 182. Igor Sokolov; Encapsulation of molecules in mesoporous silica particles:
Principles and applications
0930 183. Peng Jiang; Templated fabricationof hollow gold nano-grenade particles for
controlled drug delivery
0945 184. Anil Kumar Anal; Biopolymeric microparticles for encapsulation of live cells –
Biotransport and biocompatibility considerations
1015 Break
1030 185. Chi-Hwa Wang; Electrospray in the dripping mode for cell microencapsulation
1100 186. Cory Berkland; Translating therapeutic nanoparticles
1130 187. Eric Daniels; Formation and characterization of P(NIPAM) core/shell polymer
particles
1145 188. Julie Champion; Particles with complex shape
1215 End of Session
Session C2 (Monday, 0900-1200, Azaela) Particle Arrays & Photonics
Session Chair: Alamgir Karim
0900 189. Paul Braun; Molecular recognition based permanent assembly of non-FCC
colloidal crystals
0930 190. Oksana Kasyuticho; Protein-guided 3D -assemblies of magnetic nanoparticles
0945 191. Amr Abdel-Fattah; Acoustically-induced microparticle orbiting and clustering
on a solid surface: Origin and implications
1010 Break
1030 192. Stephen Foulger; Crystalline colloidalo arrays: Applications from filters to
lasers
1055 193. Cefe Lopez; Photonic glasses as matrices for random lasers
21
1120 194. Shigeru Watanabe; Fabrication of ordered 2D arrays of nanoparticles using selfassembled diblock copolymer templates
1145 195. Eckhard Goernitz; Light diffraction on polymer particle arrays in the optical farand near-field
1200 End of Session
Session D2 (Monday, 0900-1220, Marathon-Cedar) Particle Characterization
Session Chair: Ian Morrison
0900 196. Helmut Coelfen; Keynote - Particle analysis using a multiwavelength detector on
the analytical ultracentrifuge
0930 197. Helge Kristiansen; Mechanical characterization of micro-meter sized
monodisperse polymer particles
0945 198. Mark Poggi; Quantifying real-time changes of nano-scale interactions at
surfaces using quartz crystal microbalance with dissipation monitoring
1000 199. Yao Kanga; Adsorption of low molecular weight isothiazoline biocides on
minerals and their subsequent desorption from a paint film
1015 Break
1030 200. Frank Scheffold; Heterogeneous dynamics in a drying colloidal thin film
1055 201. Alex Smirnov; Interfacial electrostatics of monolayer-protected gold clusters by
molecular probes
1120 202. Ai Tee Tok; Comparison and analysis of three P.A.T. techniques in a pilot-scale
fluidized bed granulator
1135 203. Thuy T. Chastek; High throughput non-aqueous dispersion polymerization using
a micro-reactor and on-line dynamic light scattering
1150 204. Judith Hadley; Nanoparticle measurement by spectroscopic Mie scattering
1205 205. Carla Bellomunno; Experimental correlation between particle size and laser
induced incandescence (LII) time decay in TiO2 flame synthesis
1220 End of Session
Session E2 (Monday, 0900-1215, Biscayne-Siesta) Particle Based Devices
Session Chair: Frank Koo
0900 206. Tadashi Kawazoe; Keynote - Nanophotonic devices using coupled
nanoparticles with virtual photons and polaritons
0935 207. Nick Kotov; Keynote - Driving forces in nanoparticle assembly
1010 Break
1030 208. Seong Jin Koh; Large-scale fabrication of single electron devices utilizing
colloidal nanoparticles
1100 209. Laura Steller; Light-activated nanoparticles for ion channel applications
1115 210. Hans-Gerd Boyen; Nanoparticles for magnetic recording: The pros and cones of
self-assembly
1145 211. Dimitris Tsoukalas; Memory effects in insulators incorporating semiconducting
or metallic nanoparticles
1215 End of Session
Session F3 (Monday, 0900-1210, Jasmine) Particle Based Advanced
Materials
Session Chair: Lyudmila Bronstein
0900 212. Bernie Binks; Keynote - From foams to ‘dry water’: Phase inversion of particlestabilized materials
0930 213. Nathalie Herlin-Boime; Size controled (3-5 nm) silicon nanocrystal synthesis
and applications
22
0945 214. Stefan Bon; Supracolloidal structures through liquid-liquid interface driven
assembly
1010 Break
1030 215. Yunfeng Lu; Novel assembly approach towards energy-material particles
1055 216. Todd D. Krauss; Ultrabright lead selenide quantum dot nanoclusters
1120 217. Vince Rotello; Integrating top-down fabrication with bottom-up self-assembly
1135 218. Elodie Bourgeat-Lami; Incorporation of laponite clay platelets into polymr
latexes: Evidence of clay localization by cryo-TEM imaging
1200 End of Session
Monday Afternoon, May 12, 2008
Session A5 (Monday, 1400-1730, Magnolia) Advanced Particle Synthesis
Session Chair: Richard Brotzman
1400 219. Ganesh Skandan; Strategies for implementing nanomaterials in commercial
applications
1430 220. Ingo H. Leubner; The nucleation phase: An evaluation of two models
1445 221. François Ganachaud; François Ganachaud; New insights on nanopreciptiation
by solvent shifting
1515 Break
1530 222. Chris Roberts; Metal and semiconductor nanoparticle deposition and
separation using CO2-expanded liquids
1600 223. Yousef Bakhbakhi; Supercritical particle formation: Kinetic parameter
estimation
1615 224. Steve R. Duke; Visualization of spray and particle characteristics of SAS
precipitation of PMMA, PVP, and copolymers
1630 225. Liberato Manna; Synthesis, properties and perspectives of complex nanocrystal
structures
1700 226. Jung Hyun Kim; A novel route for nanostructured luminescent nanoparticles via
Fe3+-cata Hoa lyzed oxidative polymerization in aqueous medium
1730 End of Session
Session G3 (Monday, 1400-1725, Oleander B) Particle Based Diagnostics
Session Chair: Qun Huo
1400 227. Vince Rotello; Keynote - Protein sensing using nanoparticle-fluorescent
polymer complexes
1430 228. Nicola Pinna; Resistive chemical sensors from metal oxide nanocrystals
synthesized in organic solvents
1445 229. Wolfgang Parak; Fluorescence labeling of biological cells and creating
programmable materials with biofunctionalized colloidal quantum dots
1510 Break
1530 230. Gil Markovich; Metal nanoparticle plasmons interacting with chiral molecules
1555 231. David Thompson; Rapid detection of S-adenosylhomosysteine using selfassembled opticl diffraction gratings
1620 232. Jawad Naciri; Multicolor liquid crystal nanoparticles as efficient fluorescent
reporters in bioimaging and biosensors
1635 233. Alex Wei; Plasmon-resonant nanorods as theragnostic agents
1700 234. Shengli Zou; Metal nanoparticles and their sensing applications
1725 End of Session
23
Session H2 (Monday, 1400-1715, Oleander A) Particles In Drug and
Chemical Delivery
Session Chair: Si-Shen Feng
1400 235. Giulio F. Paciotti; Keynote - Developing tumor-targeted nanotherapeutics on
colloidal gold nanoparticles
1430 236. Elena Dormidontova; Optimization of nanoparticle architecture for enchanced
targeting in drug deliver
1445 237. Kei Nakai; Development of boron nanocapsules for neutron capture therapy
1510 Break
1530 238. Ram Gupta; Formation of drug particles of controllable size using supercritical
CO2
1555 239. Jennifer Fiegel; Particulate aerosols for the treatment of respiratory infections
1620 240. Janne Raula; Novel inhalation drug powders with crystalline L-leucine
1635 241. Balaji Panchapakesan; Integrated molecular targeting, imaging, and selective
killing of breast cancer cells using carbon nanotubes
1700 242. Xian-Wen Wei; Monodisperse magnetic ferrite/carbon core-shell
nanostructures: Fabrication and applications
1715 End of Session
Session C3 (Monday, 1400-1715, Azaela) Particle Arrays & Photonics
Session Chair: Paul Braun
1400 243. Joydeep Dutta; Keynote - Bacteria and fungi as templates for self-organization
of gold nanoparticles
1440 244. Yadong Yin; Synthesis, self-assembly and field-responsive optical diffractions
of superparamagnetic colloids
1510 Break
1530 245. Tsutomu Sawada; Tunable gel films of single domain colloidal photonic crystals
1600 246. Peng Jiang; Shear-aligned assembly of colloidal photonic crystals
1615 247. Shlomo Berger; Array of non-linear dielectric nanocrystals
1645 248. Zhaoxiang Deng; DNA assisted assembly of linear nanoparticle arrays on
carbon nanotubes
1715 End of Session
Session J2 (Monday, 1400-1710, Marathon-Cedar) Particle Surface
Modification
Session Chair: Dieter Trau
1400 249. Heinrich Hofmann; Keynote - Manufacturing of multifunctional nanoparticles
1435 250. Steffen Pilotek; Chemomechanical surface modification of inorganic
nanoparticles
1450 251. Gil Rosenman; Electron-induced surface modification: Physics and technology
1515 Break
1530 252. Carl Tripp; The use of supercritical CO2 for conducting silane reactions on
surfaces
1555 253. David E. Cliffel; Advances in protein mimics using peptide-coated nanoparticles
1620 254. Ron Cook; Self-assembled nanostructures via nanoparticle surface
functionalization
1645 255. Zheng Hu; Growth mechanism, structural regulation and functionalization of
carbon-based nanotubes
1710 End of Session
24
Session L1 (Monday, 1400-1700, Biscayne-Siesta) ...Somes
Session Chair: Heinrich Haas
1400 256. Wolfgang Meier; Keynote - Polymer vesicles with highly selective permeability
1440 257. Andreas Jahn; Novel formation of nano-liposomes encapsulating a hydrophilic
drug simulant in a continuous flow microfluidic system
1455 258. Stefan Hupfeld; Size analysis of liposomes by both photon correlation
spectroscopy (PCS) and asymmetric flow field-flow fractionation (AF4)
1510 Break
1530 259. David Thompson; Keynote - Vectorial transplantation of phi29 gp10 connector
protein into C20BAS liposome membranes
1610 260. Paul Geutjes; Lyophilisomes: A new type of bio(capsule)
1645 261. Ben J. Boyd; Equilibrium and nonequilibrium structure of liquid crystal
nanoparticles
1700 End of Session
Session F4 (Monday, 1400-1710, Jasmine) Particle Based Advanced
Materials
Session Chair: Gil Markovich
1400
1430
1445
1510
1530
1555
1620
1645
1710
262. Emmanuel P. Giannelis; Keynote - Nanoparticle based ionic material
263. Zhiming Qiu; Nanofluids for coatings and resins
264. Michael Z. Hu; Molecular engineering of inorganic nanoparticle and strucutures
Break
265. Song Jin; Biomimetic assembly of inorganic nanoparticles and nanomaterials
266. Howard Wang; Sintering of metal nanoparticles
267. Lei Zhai; Multifunctional polyelectrolyte/nanoparticle coatings
268. Takeo Ebina; Preparation and properties of clay-based self-standing films
End of Session
Tuesday Morning, May 13, 2008
Plenary 3 (Tuesday 0800-0850), Citrus Ballroom)
Session Chair: Markus Niederberger
0805 324. Plenary 3 - Orlin Velev; Janus particles - Unusual properties and use as
components of complex anisotropic materials
Session A6 (Tuesday, 0900-1205, Magnolia) Advanced Particle Synthesis
Session Chair: Liberato Manna
0900 325. Roger Leblanc; Keynote - Enzyme quantum dot factory
0940 326. Corine Gérardin; Assemblies of hydrophilic block copolymers - Templates for
nanoparticles and nanomaterials synthesis
1010 Break
1030 327. Lakshminarayanan Ragupathy; Lipase catalyzed polycondensation reactions in
miniemulsion to synthesize polyamide nanoparticles
1045 328. Debasis Bera; In situ and ex situ time-evolution study of photoluminescence
from ZnO/MgO core/shell quantum dots
1100 329. Benjamin L. Holt; A novel route to highly tunable emulsions including single
step multiple emulsion formation
1115 330. Roberta Brayner; Micro-algae and nanoparticles: Towards “living” materias.
Bio-controlled synthesis of nanoparticles with optical and magnetic properties
25
1145 331. Fabienne Gauffre; Amphiphilic diblock and triblock stabilizers for waterdispersible nanoparticles
1200 End of Session
Session G4 (Tuesday, 0900-1225, Oleander B) Particle Based Diagnostics
Session Chair: Hedi Mattoussi
0900 332. Tobias Hertel; Development and exploration of carbon nanotubes towards use
as probes and agents in physical and life-sciences
0930 333. Piotr J. Cywinski; Nanosensor-based detection of oxygen in biosamples
0945 334. Kui Yu; Synthesis and characterization of photoluminescent colloidal quantum
dots for cancer cell imaging
1015 Break
1030 335. Tigran Shahbazyan; Cooperative plasmon-mediated molecule fluorescence near
metal nanoparticles
1055 336. Anne-Laure Papa; Titanium oxide nanotubes synthesis and surface
modification for DNA transfection
1110 337. Achim Weber; Biofunctional core-shell nanoparticles for biochip manufacturing
by print processes
1135 338. Swadeshmukal Santra; Multimodal/multifunctional nanoparticles for biomedical
applications
1200 339. Long Jiang; Application of nanogold to biomolecular recognition
1225 End of Session
Session B3 (Tuesday, 0900-1200, Oleander A) Particle Encapsulation
Session Chair: Neal Vail
0900 340. Thomas Scheibel; Spider silk proteins - Biopolymers for encapsulation,
coatings and more
0930 341. Gianny Rossini; Oligonucleotide coated metallic nanoparticles as a flexible
platform for molecular imaging agents
0945 342. Laurie Gower; Biomimetic processing of soft-hard core-shell microcapsules
1015 Break
1030 343. Miriam Gathen; Innovative encapsulation for diamond composite compaction
1100 344. Umaporn Paiphansiri; Fabrication of functionalized polyurethane nanocapsules
via inverse miniemulsion for exploiting as cell markers
1115 345. Curt Thies; The behavior of individual micro/nano capsules immersed in liquids
1145 346. Cornelis G. de Kruif; Casein protein nano gels for encapsulation of minerals
1200 End of Session
Session M1 (Tuesday, 0900-1215, Azaela) Magnetic Particles
Session Chair: Claus Feldmann
0900 347. Geok Bee Teh; Structural and magnetic properties of magnetoplumbite-type
cation-substituted barium ferrite nanoparticles
0925 348. Aiguo Wu; Preparation, characterization, and applications of
superparamagnetic nanoparticles
0940 349. Thibaud Coradin; Design and properties of hybrid magnetic carriers (HYMAC)
0955 350. L. Hong; Synthesis and characterization of magnetic nanoparticles
functionalized with ?–cyclodextrin for bioseparation
1010 Break
1030 351. Tong Leung; Ferromagnetic core-shell nanoparticles: Growth control and
surface chemistry
1055 352. Everett Carpenter; Synthesis of magnetic nanoparticles for biomedical
applications
26
1120 353. Guylhaine Clavel; Nonaqueous sol-gel routes to diluted matnetic oxides
1135 354. Jian-Ping Wang; Design and fabrication of heterostructured magnetic
nanoparticles and nanoparticle-crystals for biomedical applications
1200 355. Chen-Zhong Li; Magnetic particle based nanobiomarkers for sensing
application
1215 End of Session
Session D3 (Tuesday, 0900-1225, Marathon-Cedar) Particle Characterization
Session Chair: Miran Mozetic
0900 356. Richard Vanfleet; Electron microscopy characterization of chemical order in
small nanoparticles
0930 357. Ben Lich; Quantitative particle analysis based on electron microscopy imaging
data
0945 358. Inga Ennen; Magnetic nanoparticles and XMR-technology: A combined tool for
single molecule detection
1010 Break
1030 359. Hani Nur; Heteroflocculation studies of deformable and non-deformable
polymeric particles
1045 360. Leonardo Cinque; Particle outliers and contaminants – Looking for the needle in
the haystack
1100 361. Maria T. Celis; Characterization of dispersed systems using multiwavelength
transmission measurements
1125 362. Milan Sykora; Size-dependent intrinsic radiative decay rates of silicon
nanocrystals at large confinement energies
1140 363. Gautam Mukhopadhyay; Scattering of EM waves by small magnetic particles
1155 364 Paul G. Jones; Characterising the dispersion of fine and ultra-fine calcium
carbonate particles in polypropylene
12105 End of Session
Session E3 (Tuesday, 0900-1215, Biscayne-Siesta) Particle Based Devices
Session Chair: J. Adin Mann, Jr.
0900 365. Sandra Rosenthal; Encapsulated white-light CdSe nanocrystals as
nanophosphors for solid state lighting
0930 366. Wallace C.H. Choy; Improved spontaneous emission of a nano-fluorophore in
metal nanoshells with plasmonic resonance
0945 367. Brian Korgel; Colloidal CIGS particles: A precursor route to ultra low cost
photovoltaics
1015 Break
1030 368. Luigi Martiradonna; Enhancement of the emission of colloidal nanocrystals
embedded in photonic devices
1100 369. Chunye Xu; Electrochromic polymer windows
1130 370. Nina Kovtyukhova; 3D functional heteronanostructures made by assembly and
shaping of nanoparticle-film systems
1200 371. Alessandro Martucci; A novel metal/semiconductor epitaxial interface: SiO2 film
containing cookie-like Au-NiO nanoparticles showing gas sensing properties
1215 End of Session
Session F5 (Tuesday, 0900-1220, Jasmine) Particle Based Advanced
Materials
Session Chair: Marc Porter
0900 372. Martin Steinhart; Morphology design in recyclable nanoporous templates –
Towards high-throughput production of tailor-made nanofiber arrays
27
0930 373. Anitha Ethirajan; Template assisted hydroxyapatite crystallization using gelatin
nanoparticles synthesized via miniemulsion process – A biomimetic approach
0945 374. Michael A. Markowitz; Effects of surface imprinting on the selectivity of
organosilica sorbents for preconcentration
1015 Break
1030 375. Ming Su; Exploring nanostructured materials by fiber-drawing
nanomanufacturing
1100 376. Gil Markovich; Wet chemical deposition of fine metal nanowire network films on
surfaces
1115 377. Mauricio Terrones; Synthesis and applications of doped carbon nanotubes:
New materials with enhanced properties
1145 378. Horng-Show Koo; Synthesis, dispersion and characteristics of nanoparticlebased resists for droplet printing
1215 End of Session
Tuesday Afternoon, May 13, 2008
Session A7 (Tuesday, 1400-1700, Magnolia) Advanced Particle Synthesis
Session Chair: Eric Daniels
1400 379. Claus Feldmann; Nanoscale hollow spheres: Synthesis and properties
1430 380. Du-Jeon Jang; Optical fabrication of hollow and core-shell metal nanospheres
1500 381. Ahmet Faik Demirors; Synthesis and characterization of eccentric titania silica
core-shell and composite particles
1515 Break
1530 382. Kuo Chu Hwang; Production, growth mechanism, and applications of core-shell
iron/carbon nanoparticles
1600 383. Yuri K. Gun’ko; Magnetic nanoparticles from metallorganic precursors
1615 384. Yonglin Liu; Synthesis, characterization and assemblies of gold nanorods and
copper nanocrystals
1630 385. Jitendra Kumar; Magnetic behavior of manganese oxide nanoparticles obtained
by thermal decomposition of sol-gel derived oxalates
1645 386. Xiong Liu; Monofunctional gold nanoparticles prepared from a noncovalent
interaction based solid phase modification approach
1700 End of Session
Session A8 (Tuesday, 1400-1645, Oleander B) Advanced Particle Synthesis
Session Chair: Roberta Brayner
1400 387. Haruma Kawaguchi; Keynote - Inorganic/organic composite microspheres with
temperature sensitivity
1440 388. Rex Hjelm; Synthesis, characterization and phase transitions of small, smart
microgel particles
1510 Break
1530 389. Huiliang Wang; Micro- and nanosphere crosslinked hydrogels with high
mechanical strength and special optical properties
1600 390. Hsien-Hsin Tung; Effects of energy on the nucleation of drug nanoparticles
under high supersaturation
1615 391. John Texter; Nanoparticle latexes from reactive ionic liquid surfactants
1645 End of Session
28
Session H3 (Tuesday, 1400-1715, Oleander A) Particles In Drug and
Chemical Delivery
Session Chair: Manny Perez
1400 392. Tomoaki Hino; Thermal gelation of oil-in-aqueous curdlan emulsions
1430 393. Iris V. Schumacher; Synthesis and characterization of DNA mesospheres as
drug delivery carriers for intratumoral chemotherapy
1445 394. Wolfgang Sigmund; Benign nanoparticles for biomedical applications
1510 Break
1555 396. Adriana R. Pohlmann; Molecular organization of drug carrier polymeric
nanoparticles
1620 397. Clemens K. Weiss; Preparation and functionalization of
poly(butylcyanaoacrylate) nanoparticles as drug carrier systems for the brain
1635 398. Jarno Salonen; Fabrication of ligand-conjugated magnetic nanoparticles from
mesoporous silicon for targeted drug delivery
1650 399. Heinrich Haas; Drug loading to lipid-based colloidal carriers
1715 End of Session
Session C4 (Tuesday, 1400-1655, Azaela) Particle Arrays & Photonics
Session Chair: Stephen Foulger
1400 400. Yoshihiko Takeda; Keynote - Nonlinear dielectric function of metal
nanoparticles and optical switching
1435 401. Seiichi Furumi; Polymer colloidal crystals for laser applications
1510 Break
1530 402. Andre Gesquiere; Composite conjugated polymer-fullerene nanoparticles as
model systems for the study of optoelectronic processes in organic photovoltaic
devices
1605 403. Winston Schoenfeld; Self-assembled quantum dots within photonic crystal
nanocavities for the realization of quantum networks
1640 404. Serge Ravaine; Elaboration of photonic colloidal crystals with a well-defined
architecture
1655 End of Session
Session J3 (Tuesday, 1400-1705, Marathon-Cedar) Particle Surface
Modification
Session Chair: Carl Tripp
1400 405. Jon A. Preece; Keynote - Nanostructuring surfaces into 3D: Integrating
lithography and self-assembly
1430 406. Cédric Louis; New tracers and biological systems based on multifunctionnal
nanosized hybrid particless
1445 407. Serge Ravaine; A chemical synthetic route to colloidal molecules
1510 Break
1530 408. Yoshinori Yamanoi; Structures of gold nanoparticles immobilized onto
hydrogen-terminated silicon(111) surface
1555 409. Jung Jin Park; Langmuir adsorption study of CdSe/ZnS quantum dots on
synthetic templates: Influence of substrate surface chemistry
1610 410. Kenneth Lau; Coating and functionalization of particles using initiated chemical
vapor deposition (iCVD)
1635 411. Lucienne Juillerat-Jeanneret; Surface functionalization of nanoparticles for cellTargeted drug delivery
1650 412. Kamil Rahme; Block copolymers for the stabiliZation of gold nanoparticles in
water
1705 End of Session
29
Session E4 (Tuesday, 1400-1700, Biscayne-Siesta) Particle Based Devices
Session Chair: Chunye Xu
1400 413. Neil Kemp; Keynote - Bridging the gap: From conducting polymer nanowires to
molecular and single atom devices
1430 414. Alireza Nojeh; Electron induced field-emission from carbon nanotubes
1500 415. Jeffrey M. Pietryga; Utilizing the lability of lead chalcogenides to produce
heterostructured nanocrystals with bright, stable infrared emission
1515 Break
1530 416. Yasuhiko Hayashi; Synthesis and characterization of carbon nanotube
encapsulated ferromagnetic metal nanowires: Towards spin electronic
applications
1600 417. Richard Baldwin; Silver nanowires - A low volume additive for high thermal and
electrical conductivity
1615 418. Saiful I. Khondaker; Large scale fabrication approach of carbon nanotube based
electronic devices
1645 419. Giuseppe Compagnini; Raman spectroscopy of carbon nanotubes and
nanowires prepared by arc discharge in liquid nitrogen
1700
End of Session
Session F6 (Tuesday, 1400-1710, Jasmine) Particle Based Advanced
Materials
Session Chair: Lennart Bergstrom
1400
1435
1510
1530
1605
1620
1655
1710
30
420. Muhammed S. Toprak; Cooperative assembly routes for nanocomposites
421. Tommy Horozov; Solid particles in liquid films
Break
422. Miguel A. Garcia; Tailoring the physical properties of gold nanoparticle/polymer
composites
423. Liang Hong; Grafting oligomeric ionomers to silica nanoparticles via ATRP and
applications in PEMs for fuel cells
424. S. S. Wong; Synthesis and applications of classes of non-carbonaceous
nanostructures
425. Pierre Sarrazin; Functional paper based on photoluminescent nanoparticle
adsorption on modified cellulose fibers
End of Session
Technical Program – Poster Sessions
Poster Session P1 (Sunday, 1800-1930, Citrus Ballroom)
Session Chair: John Texter, Eastern Michigan University
Advanced Materials
109. Lisandra Arroyo-Ramírez; Palladium-cobalt nanoparticules on carbon surfaces: An
electrochemical and surface analysis
110. Douglas A. Gish; Optical properties of noble metal nanoparticle films produced by
glancing angle deposition
111. Elin Hammarberg; Microwave-polyol synthesis of TCO nanocrystals
112. Regine Hedderich; Spontaneous structure formation on the nanoscale
113. Dylan D. Jung; Rotational moulding of fiber-reinforced integral skin PE foam
composites
114. Victor M. Menéndez-Flores; Stability of Ag-TiO2 photocatalysts assessed by a
photocatalytic degradation of dichloroacetic acid
115. Priyadarshi Panda; Stop-flow lithography of colloidal, glass, and silicon
microcomponents
116. Renate Rossmanith; Synthesis of porous anatase nanoparticles and Au/TiO2
nanomaterials by miniemulsion technique
117. Steven R. Saunders; Nanoparticle size-selective fractionation process using CO2expanded liquids at different processing scales
118. Alessandro Martucci; Luminescence and amplified stimulated emission of
CdSe@ZnS quantum dots doped TiO2 and ZrO2 waveguides
Advanced Particle Synthesis
119. Nelson S. Bell; Zinc oxide nanorod synthesis from nanoparticles in 1,4-butanediol
solvent
120. Marissa Caldwell; Synthesis and characterization of germanium chalcogenide
nanoparticles
121. Youcun Chen; Synthesis and electrocatalytic activity of Pt/Co3O4 nanocomposites
122. Gregory Kalyuzhny; Ultrasmall magic-size CdSe nanocrystals: Synthesis, chemistry
and optical properties
123. Gabriele Kremser; Characterization of ZnS nanoparticles prepared by a fast and
facile synthesis route
124. Ramalinga Viswanathan Mangalaraja; Synthesis of crystalline rare earth doped ceria
nano-spheroids
125. Yoshitake Masuda; Liquid phase morphology control of anisotropic oxide particles –
TiO2, ZnO, Batio3
126. Nadine Millot; Continuous hydrothermal synthesis of nanometric oxides in
supercritical conditions
127. Nicola Pinna; Nonaqueous sol-gel routes to metal-oxide nanocrystals, hybrid
materials and thin films
128. Dong-June Park; Polycaprolactone nanoparticles as resveratrol carrier systems:
Effect of dispersed phase solvent on properties of nanoparticles prepared by
emulsion solvent evaporation method
129. Vanessa Prevot; Enzymatic synthesis of layered double hydroxides
130. Rocío Redón; Solvent influence on palladium nanoparticle synthesis
131. America Vazquez-Olmos; Spectroscopic study of BiFeO3 and YFeO3 nanocrystals
produced by a solvent-free method
132. Zheng Xu; New electrostatic dispersion method dispersing fine powder in air
31
Technical Poster Program (continued)
Characterization
133. Mo Abubakar; Controlled sedimentation of concentrated colloidal suspensions
134. Steven Africk; A novel method for the characterization of particle and nanoparticle
suspensions
135. Jean-Francois Berret; Size distribution of superparamagnetic particles and clusters
determined by magnetic sedimentation
136. Donald J. Burnett; Surface energy distribution on the surface of milled and
crystallised lactose
137. Donald J. Burnett; Differences in the amorphous state in differently processed
lactose powders
138. Ana Morfesis; Physicochemical characterization of nanosize zinc oxide and titanium
dioxide used as UV sunscreen agents in cosmetic formulations
139. Irina Chernyshova; Probe-molecule FTIR spectroscopy for sensing acid-base and
redox properties of metal oxide nanoparticles in aqueous media
140. Nadia J. Edwin; Use of fluorescence correlation spectroscopy for studying
polyelectrolyte-nanoparticle interaction
141. Mark Gostock; Bionanotechnology and biomolecules on surfaces studied by dual
polarization interferometry
142. Ulf Nobbmann; Sucrose - A new sub-nanometer size standard?
143. Amra Tabakovic; Evaluation of Ag-core silica nanoparticle stability during the high
performance liquid chromatography dispersion process: Surface charge and
solution effects
144. Betina Zanetti-Ramos; Dynamic light scattering, atomic force microscopy and
transmission electron microscopy characterization of polyurethane nanoparticles
Diagnostics
145. Yong Taik Lim; Plasmonic magnetic nanoparticles for biomodal imaging and
photonic-based therapy of cancer cells
146. Erhan I. Altinoglu; Indocyanine green-encapsulated calcium phosphate nanocolloids
as bioresorbable near-infrared imaging agents
147. Piotr J. Cywinski; Biocompatible nanosensor systems for measuring pH in cells
148. Sungho Ko; Sensitivity enhancement of SPR immunosensor by nanoparticles and a
novel biolinker protein
149. Sonia Kumar; Magnetic relaxation diagnostics using superparamagnetic iron oxide
nanoparticles
150. Sudip Nath; Dextran-coated gold nanoparticles for the assessment of antimicrobial
susceptibility
Drug and Chemical Delivery
151. José F. Almeida; Photo-crosslinked dextran gels as drug delivery systems
152. Yao-Da Dong; Adsorption of loaded liquid crystalline particles at surfaces
153. Hanna Mouaziz; An innovative concept of targeting using mononuclear phagocytes
as carrier for therapeutic nanosystems
154. Aravind Chakrapani; Evaluation of nanoparticles as a vaccine delivery system
155. Thuy T. Chastek; Monodispersed biocompatible thermally responsive nanoparticle
hydrogels
Surface Modification
156. Brian C. Benicewicz; Functionalization of silica nanoparticles by surface-initiated
RAFT polymerization and click chemistry
32
157. Hee Jung Choi; Preparation of surface modifiers for multi-walled carbon nanotubes
through nitroxide mediated polymerization technique and their application for the
fabrication of counter electrodes for dye sensitized solar cells
158. Qiu Dai; Synthesis and surface modification of citrate-protected gold nanoparticles
for biomolecular detection
159. Sung Chul Hong; Preparation of polystyrene based functional block copolymers
through nitroxide mediated polymerization technique and their applications as
surface modifiers for nanoparticles and nanotubes
160. Nanjundan Ashok Kumar; A facile approach to graft poly(3,4propylenedioxythiophene) on multiwalled carbon nanotubes
161. Jung Min Lee; Adhesion and particle deformation of submicron-sized latex particle
on hydrophobically-modified solid substrates at room temperature
162. Yu Li; Functionalization of silica nanoparticles by surface initiated RAFT
polymerization and click chemistry
163. Clara Pereira; Silica nanoparticles functionalized with organosilanes for
immobilization of chiral and Mn(III) salen complexes
164. Parul Rungta; Dynamic light scattering study of propargyl acrylate particles modified
with poly(ethylene glycol)
Poster Session P2 (Monday, 1800-1930, Citrus Ballroom)
Session Chair: John Texter, Eastern Michigan University
Advanced Materials
269. Emanuela Tamburri; Nanoparticles of high dielectric materials as innovative coating
of carbon nanotubes
270. Doris M. Spori; Self-cleaning surfaces by the use of silica nanoparticles
271. Pagati Mukhopadhya; On magnetic nanoparticles in a colloidal fluid
272. Eckhard Goernitz; Self-assembly of polymer microspheres for the preparation of 3D
optical phase gratings
273. Eckhard Goernitz; Organic-inorganic nanocomposites for volume holographic
elements
274. Hyun Woo Lee; One-pot synthesis of titania based sulfonated polyaniline
nanocomposites by UV-curing
275. Mohammad Rezaul Karim; UV-curing synthesis of water soluble sulfonated
polyaniline-silver nanocomposites by in situ reduction
276. Min Sung Kim; UV cross-linked poly(4-vinylpyridine) polymer surfaces as templates
for the preparation of bi-modal gold nanoparticles
277. Jasmeen Kaur; Effect of particle surface area on properties of hydroxyapatite
nanocomposites
278. Andreas Pein; Synthesis and characteriZation of ZnO-nanoparticles and ZnOpolymer nanocomposites
279. Lei Qian; High efficiency photoluminescence from silica-coated CdSe quantum dots
280. Isaac Ojea Jiménez; Study of induced aggregation of gold nanoparticles capped by
peptides: The destabilizing role of the stabilizer
281. Johan Stiefelhagen; Incorporating lanthanides in silica colloids
282. Donald J. Burnett; Determining the moisture-induced glass transition in amorphous
pharmaceutical powders
283. Kee Wu; Nanopigments for flat panel displays
33
Advanced Particle Synthesis
284. Mathias Lakatos; Fluorescent Au clusters surrounded by dendritic oligosaccharide
shells and their optical properties in water
285. Wensheng Lu; The photoelectric response of hydrophobic gold nanoparticles and
gold/silica monolayers
286. Kendal M. Hurst; Gold nanoparticle deposition via gas-expanded liquids for improved
micromachine reliability
287. Ekaterina Dovgolevsky; Probong the transition mechanism between quasi-spherical
and cubic gold nanoparticles
288. Geok Bee Teh; Effect of CTAB on the synthesis of photoluminescent silver
nanoparticles
289. Alexander Türke; Conducting silver nano-hybrid particles
290. Trong-On Do; Synthesis of nanoporous network materials with high surface areas
from the cooperative assemblage of alkyl chain-capped metal/metal oxide
nanoparticles
291. Trong-On Do; Synthesis and self-assembly of uniform rare earth orthovaladate or
molybdate nanocrystals using a solvothermal approach
292. Sanjay R. Mishra; Carbon nanospheres: “Green” synthesis, characterization, and
growth kinetics
293. Hendrik Frank; Heterophase polycondensation of polyimides in ionic liquids
294. Jessie Desbiens; Polymer core-shell nanoparticles doped with luminescent
complexes
295. Hani Nur; Analysis of monomer composition in copolymer microgel particles
296. Hani Nur; Novel surfactant microgel particles: Synthesis and applications
297. Keith Redford; Monodisperse polymer particles: Characterisation and self-assembly
in suspension
298. Andreas Lammel; Formation mechanisms and processing conditions for engineered
spider silk microspheres
299. Jeong Geun Kim; Particle size control of carboxylate SB-latex
300. Sun Jong Lee; Luminescent polystyrene nanoparticles prepared by Fe3+ catalyzed
oxidative polymerization in aqueous medium
301. Ramalinga Viswanathan Mangalaraja; A facile route for the synthesis of crystalline
yttria nanospheroids
302. Ramalinga Viswanathan Mangalaraja; Nano-grained zirconia ceramics through
extrusion of particulate gels
303. Elodie Bourgeat-Lami; Miniemulsion copolymerization of styrene and gamma
methacryloxy propyl trimethoxysilane
304. Marcel Ruppert; Polymerization of 3,4-ethylenedioxythiophene in miniemulsion with
Fenton’s reagent
305. Maiby Valle-Orta; Easy and fast zero-valent copper and iron nanoparticles synthesis
306. Anna Lähde; Simultaneous synthesis and coating of pharmaceutical nanoparticles
with L-leucine in the gas phase
307. Ingo H. Leubner; Four crystal nucleation models: An evaluation for practical
applications
308. Kouki Fujioka; Silicon dots and their cyto-toxicity
309. Pilaslak Akarachalanon; Preparation and evaluation of liposomes containing clove oil
Diagnostics
310. Noriyoshi Manabe; Imaging transparent vitreous of the eye using nanoparticles
311. Charalambos Kaittanis; One-step nanoparticle-mediated bacterial detection with
magnetic relaxation
34
312. Virginia Bouzas; Iron oxide nanoparticles prepared by laser pyrolysis for biomedical
applications
313. Mark Gostock; Bionanotechnology and biomolecules on surfaces studied by dual
polarization interferometry
314. Xiong Liu; A one-step homogeneous immunoassay for cancer biomarker detection
using gold nanoparticle probes coupled with dynamic light scattering
315. Christian Zink; Morphological gradients for cell biology
316. Chiung Wen Kuo; Selected cell patterning using colloidal lithography
Drug and Chemical Delivery
317. Ben J. Boyd; Tailoring the pharmacokinetic behavior of poly-L-lysine dendrimers for
their use as controlled drug delivery vehicles
318. Corine Gérardin; Polyion complex micelles for ex vivo dendritic cell therapy:
Formation and characterization
319. Susann Schachschal; Novel stimuli-responsive microgel systems with amphoteric
behaviour for enzyme immobilization
Encapsulation
320. Edurne Erkizia; Synthesis and characterization of silica microcapsules containing
materials of different viscosity
321. Thomas T. Morgan; The synthesis and characterization of dye-encapsulated calcium
phosphate nanoparticles
322. Joseph Reiner; Fluorescence based liposome encapsulation studies
323. Eva Rosenbauer; Functionalized polyurea nanocapsules via reaction at interface of
miniemulsion droplets
35
36
Abstracts of Oral Program
Plenary 1
1
BUILDING WITH ARTIFICIAL ATOMS: ROUTES TO MULTIFUNCTIONAL NANOCRYSTAL BASED MATERIALS AND DEVICES
E. Shevchenko, J. Urban, D. V. Talapin. and Christopher. B. Murray,
Departments of Chemistry and Materials Science and Engineerin, University
of Pennsylvania, 231 South 34th Street, P.O. Box 394, Philadelphia PA
19104-6323, USA; [email protected]
The synthesis of colloidal nanocrystals with controlled crystal shape, structure and
surface passivation provides a rich family of nanoscale building blocks for the assembly
of new solid thin films and novel devices. The tunability of the electronic, magnetic, and
optical properties of the nanocrystals has lead to them being compared to a set of
"artificial atoms". This talk will briefly outline some of the current "best practices" in
preparation, isolation and characterization of semiconducting quantum dots and magnetic
nanoparticles. I will next discuss the organization of monodisperse nanocrystals in to
single component superlattices that retain and enhance many of the desirable mesoscopic
properties of individual nanocrystals. The potential to design new materials expands
dramatically with the creation binary nanoparticle superlattices BNSLs(4). I will show
how we synthesized differently sized PbS, PbSe, CoPt3, Fe2O3, Au, Ag and Pd
nanocrystals and then these nanoscale building blocks into a rich array of multifunctional nanocomposites (metamaterials). Binary superlattices with AB, AB2, AB3,
AB4, AB5, AB6 and AB13 stoichiometry and with cubic, hexagonal, tetragonal and
orthorhombic packing symmetries have been grown. We have also identified a novel
method to direct superlattice formation by control of nanoparticle charging. Although
modular nano-assembly approach has already been extended to a wide range of
nanoparticle systems, we are confident that we have produced only a tiny fraction of the
materials that will soon accessible.
37
Abstracts of the Oral Program (continued)
A1 – Invited Paper
CARBON NANOBUDTM – A NOVEL NANOMATERIAL:
SYNTHESIS, STRUCTURE, FIELD EMISSION AND TRANSPORT
PROPERTIES
Esko I. Kauppinen, NanoMaterials Group, Center for New Materials and
Laboratory of Physics, Helsinki University of Technology & VTT
Biotechnology. Puumiehenkuja 2, FIN-02150 Espoo, Finland;
[email protected]
2
We present synthesis, structure and field emission properties of a novel hybrid carbon
nanomaterial, NanoBudsTM, combining fullerenes and single-walled carbon nanotubes
(CNTs) . NanoBuds consist of fullerenes attached to the outside surface of CNTs, i.e.
nanotubes are functionalized with fullerenes. Two floating catalyst methods for their
selective synthesis have been developed, using pre-made iron catalyst particles by a hot
wire based PVD method or grown in situ via ferrocene vapour decomposition in the
presence of CO and trace amounts of H2O and CO2. TEM images show spherical
structures i.e. fullerenes at the surface of the tube. Their spherical nature was confirmed
by tilting samples within a HR-TEM. Statistical size measurements on the basis of HRTEM images revealed that the majority of fullerenes consists of C42 and C60.
Interestingly, evidence of C20 fullerenes, the smallest possible dodecahedra is found.
Raman spectra show a pronounced G-band at 1600 cm-1 associated with CNTs, and only
a weak D-band at 1320-1350 cm-1. The main peaks in MALDI-TOF spectrum are
attributed to C60 (C60H2, C60H2O) and C42 (C42COO) fullerenes. Accordingly, fullerenes
are attached to CNTs via either oxygen (preferable for fullerenes larger than C54) or
carboxylic (for smaller fullerenes) bridges, which was confirmed by FT-IR
measurements. EELS observations with TEM also showed the existence of oxygen.
Scanning tunneling microscopy (STM) and spectroscopy (STS) measurements of samples
deposited on Au(111) substrate confirmed the covalent nature of fullerene bonding to the
tube. Atomistic density-functional-theory based calculations showed that systems
composed of fullerenes and nanotubes with single vacancies covalently functionalized
through ester groups can indeed exist. In-situ deposited i.e. non-purified planar NanoBud
mats showed stable cold electron field emission with a current density of 189 µA/cm2 at
1.26 V/µm. The threshold voltage was about 0.6 V/µm, compared to over 2 V/µm for
similarly produced planar nanotube mats. We discuss sheet conductivity of nanotube and
–bud films.
A1 – Contributed Paper
MANIPULATION OF FILMS OF NANOPARTICLES
Stefan Jaksch, Fabio Zappa, Paul Scheier, Institut für Ionenphysik und
Angewandte Physik, Technikerstrasse 25, University of Innsbruck, A-6020
Innsbruck, Austria; [email protected]
3
Nanoparticles are formed upon magnetron sputtering and deposited onto highly oriented
pyrolytic graphite (HOPG). Thereby homogeneous films are grown layer by layer. The
effect of different parameters such as the distance between magnetron and graphite
surface, pressure, discharge current, deposition time and bias-voltage of the HOPG is
38
analyzed with an ultra high vacuum scanning tunneling microscope (UHV-STM) directly
connected via a shutter to the sample preparation chamber. For the present study we
analyze the dependence on the distance/geometry, pressure, current, time and also biasvoltage of the substrate. The distance/geometry has the strongest influence on the
resulting films. It is only possible to grow films of nanoparticles in a distance regime of
approximately 8cm from the sample. A bias voltage applied to the HOPG surface
indicates that the nanoparticles are predominantly negatively charged. Manipulation on
the nanometer scale such as vaporization and fusion of nanoparticles with the STM tip
can be achieved with high precision by scanning the films with increased tunneling
currents, or high bias voltages, respectively. By scanning a specific area with increased
tunneling current nanoparticles are vaporized and linescans through these regions reveal
sharp transitions from the treated to the untreated areas. Scanning with increased biasvoltage results in fusion of the nanoparticles. Furthermore the electronic density of states
is increased by this process and also better mechanical stability is observed. Lowering the
bias-voltage between tip and sample leads to the effect, that the tip wipes away the
nanoparticles without obvious damage to the tip. A combination of the above mentioned
techniques enables the formation of three dimensional relief like structures in the
nanometer regime that can be probed in STM topographs taken at non-manipulating
conditions. This work was supported by the Integrated Infrastructure Initiative ITS-LEIF.
WATER-REDISPERSIBLE SINGLE WALL CARBON NANOTUBES
FABRICATED BY IN SITU POLYMERIZATION OF MICELLES
Sung-Min Choi, Tae-Hwan Kim, Changwoo Doe, and Steven R. Kline,
Department of Nuclear and Quantum Engineering, KAIST, Daejeon, 305701, Republic of Korea; [email protected]
4
We developed a new type of non-covalently (no covalent bonding between the
dispersants and SWNTs) functionalized and individually isolated SWNTs (p-SWNT) that
are readily re-dispersible (by only 10 minutes of mild vortex mixing) in water even after
freeze-drying and stable for months long time period. This was achieved by 1) dispersing
SWNTs in water using cationic surfactants, Cetyltrimethylammonium 4-vinylbenzoate
(CTVB), which have polymerizable counterions (VB- ions), and 2) permanently fixing
the surfactant layer on the SWNTs by polymerizing the counterions. The small-angle
neutron scattering, AFM and UV-vis-NIR measurements show that the p-SWNT exists in
isolated form, being encapsulated by a cylindrical surfactant monolayer. The properties
of the p-SWNT may make it possible to prepare highly controlled dispersions of SWNTs
in water and enhance further processing in various practical applications. Support from
the BAERI program of the ministry of science and technology of Korea.
39
CHEMICALLY MODIFIED SINGLE-WALLED CARBON NANOTUBES:
SYNTHESIS AND APPLICATION IN POLYMER COMPOSITES
Karl Coleman, Christopher Herron, Anil Suri and Amit Chakraborty,
Department of Chemistry, Durham University, South Road, Durham, DH1
3LE, UK; [email protected]
5
Owing to the exceptional electronic, thermal and mechanical properties of single-walled
carbon nanotubes (SWNTs) much interest has been focused on the properties of nanotube
based polymer composites. Such composites have been found to have exceptional
strength, thermal transport properties and behave as excellent conductive plastics.
Uniform dispersion within the polymer matrix and nanotube / matrix wetting and
adhesion are all said to be important issues in the development of nanotube composites.
To date nanotube based polymer composites have focussed primarily on pristine
nanotubes, although due to their relatively inert nature the successful incorporation into a
polymer matrix to produce high performance composites has been difficult. The
interaction of the nanotube with the polymer matrix is critical. However, it should be
possible to engineer such interactions by careful control of the surface groups (and
therefore properties) of the SWNTs. It is also envisaged that modifying the surface of
SWNTs will allow us to control the dispersion of the nanotubes and avoid aggregation, a
major problem in the processing of nanocomposites. Here we present some of our recent
results in the chemical modification of SWNTs with tertiary phosphines, which have a
dramatic influence on dispersability, and describe some of their properties. The enhanced
mechanical properties of some PMMA and PEG nanocoposites containing functionalized
SWNTs (over 70% increase in Young’s modulus is observed in some cases) will also be
discussed.
MONODISPERSE SINGLE-NANO DIAMOND PARTICLES
Eiji Osawa, NanoCarbon Research Institute, AREC, Fac. Textile Sci. Eng.,
Shinshu University, 3.15-1, Tokida, Ueda, Nagano 386-8567, Japan;
[email protected]
6
Highly interesting and useful particles of single-nano diamond (SND) crystals have long
been set aside, but recent developments in the stirred-media milling technique with
micro-beads of zirconia made it possible to produce the primary particles of SND with an
average diameter of 4.8±0.8 nm in well-dispersed state on commercial basis. While it
would be a matter of time until we could isolate analytically pure and structurally simple
samples, a plethora of applicative possibilities are springing up even by using the
presently available, dark colored and a complex surface structure. This review will
disclose the latest stage of characterization, physico-chemical properties, and unexpected
behaviors of the new nanoparticles, and introduce the more promising applications under
developments in our laboratories and by the outside collaborators. By far the most
extensive efforts have been devoted to the use of SND particles as the nucleation for
growing nanocrystalline diamond (NCD) films by CVD method. Simple immersion or
40
dipping of a silicon wafer into 0.01% SND colloid in water produced even coating of the
surface with a seed density exceeding 1011/cm2. MPE-CVD on such a seeded substrate
for about 20 min afforded a 70 nm thick NCD film from grains smaller than 100 nm and
without recognizable pin holes. In order to increase the seed density towards a
theoretically attainable value of 4 1012/cm2, we are examining an ink jet patterning
instrument for propelling micro-droplets of SND colloidal solution in viscous solvent
onto a substrate surface. One interesting characteristic that were totally unknown before,
but became evident during the developments of SND is its excellent lubricating capability
in liquid media including water. While excellent friction-reducing performance was
observed with dispersions of SND in oil, frictional coefficient of the order of 0.01 has
often been recorded on metal surfaces with dilute aqueous colloids of SND. Exploration
in the nano-bio fields is by no means less vigorous. Remarkable activity of SND hydrogel
in the drug delivery recently aroused a lot of interests among nanomedical circles. Total
absence of cytotoxicity in SND, controllable and slow release of drugs in the cell from
the hydrogel, and chemical inertness of SND particles are unique advantages of the
hydrogen drug delivery. One more highly promising area of application for SND is to use
the dispersed SND particles as a reinforcing component in various solid matrices
including synthetic polymers, resins, cements, ceramics, glasses, metals and alloys.
Successful incorporation into copper and silicon will be mentioned with acquired novel
properties.
SYNTHESIS AND PROPERTIES OF NANOPARTICLES AND
NANWIRES BY LASER ABLATION IN LIQUID ENVIRONMENTS
Giuseppe Compagnini, Dipartimento di Scienze Chimiche, Università di
Catania, Viale A.Doria 6, Catania 95125 Italy; [email protected]
7
The interest around the physics and chemistry of laser ablation of solid targets submerged
in liquid environments is growing in the last few years. This is because it has been
observed that the species emerging under the non-equilibrium conditions as those
generated by the ignition of plasmas in highly confined media, can lead a variety of
different nano-systems with peculiar features, generally not achievable with other
processes. For instance these kind of procedures can be used to obtain metallic and
semiconducting nanoparticles dispersed in colloidal systems as well as a number of
different metasable phases. In this work we present the possibility to obtain a wide
variety of metallic nano-objects by ablating solid targets in liquids and by changing either
the ablation parameters (wavelength, power density, target material) and/or by
performing the ablation in different liquid environments. Most of the results will be
dedicated to the formation and properties of noble metal clusters (including monolayer
protected metal nanoparticles) and carbon nanowires. In particular laser ablation of metal
targets in water and organic liquids will be shown to generate metal colloids and to allow
the control of their shape, size and composition. Clusters’ re-shaping effects and the
formation of colloidal nano-alloys are possible through the irradiation of the formerly
obtained colloidal mixtures. Monolayer protected metal clusters will be generated
through the use of suitable organic solutions as environmental media for the ablation.
41
Carbon nanowires and other highly conjugated carbon nanostructures will be show to be
the relevant species produced after the plasma ignition in a graphite laser ablation
experiment, conducted in liquids. A variety of different chain lengths as well as hydrogen
capping or CN capping will be obtained and discussed. A comparison with other methods
in which plasmas are ignited in high density media will be provided such as those in arc
discharge experiments or laser vaporization cluster beam sources.
METALLIC NANOPARTICLES GENERATED BY ULTRA-SHORT
PULSED LASER ABLATION IN LIQUID MEDIA
Ana Menéndez-Manjón, Anne Hahn, Stephan Barcikowski; Laser Zentrum
Hannover, Hollerithalle 8, D-30419 Hannover, Germany;
[email protected], [email protected], [email protected]
8
Ultra-short pulsed laser ablation has been established as an efficient method for the
generation of nanoparticles in solution. Almost no material restrictions, stability only due
to electrostatic repulsion, preservation of stochiometry, no thermal load on the ablated
target, and the high grade of purity of obtained colloids provide advantage over other
processes. Because of these characteristics, laser-based nanoparticles are especially
demanded for the improvement of medical implants. In this field, minimal invasive
devices, such as neural electrodes, are tailored to improve bioactivity using controlled
electrophoretic deposition of nanoparticles. Pure colloidal solutions of metallic
nanoparticles were prepared in organic solvents by laser ablation. Productivity and
particle size can be controlled by ablation parameters such as laser fluence, pulse length
or pulse overlap. Higher reproducibility, productivity and stability of the colloids are
achieved inducing a circular flow in the matrix, which reduces shielding and disturbing
effects on the laser beam, and prevents initial agglomeration. Dynamics (ejection speed)
of nanoparticle generation in liquid are studied on-line by laser light scattering
velocimetry. For comparison of laser pulse duration effects, silver nanoparticles are
generated in de-ionized water with femto- and picosecond laser pulses. Productivity is
determined gravimetrically and size distributions, with TEM-imaging (Feret diameter)
and dynamic light scattering (hydrodynamic diameter). Nanoparticles are superficially
charged during the laser process. Tracking analysis of gold and NiTi alloy particles in an
electric field permits better understanding of electrophoretic mobility and the
electrophoretic deposition method. Coated devices are improved through a combination
of surface structuring and biological impact of the nanoparticulate material. Bioactivity of
silver and copper nanoparticles embedded in polymers is also demonstrated using
standard cell culture tests. These investigations show the controlled laser-based
fabrication of nanomaterials and nanofunctionalised materials in liquids, with high purity
required for biomedical, sensoric and optoelectronic applications.
42
SYNTHESIS OF IRON CONTAINING NANOPOWDERS BY LASER
PYROLYSIS FOR BIOMEDICAL APPLICATIONS
Sophie Giraud and Hicham Maskrot, CEA-Saclay,DENDANS/DMN/SRMA/LTMEx, Bât.460, 91191 Gif sur Yvette, France;
[email protected]
9
Magnetic nanoparticles present a great interest for a wide range of disciplines, such as
magnetic data storage, magnetic inks or ferrofluids, magnetic resonance imaging (as
contrast agents) and hyperthermia. However, small particles tend to agglomerate;
moreover, metal nanoparticles are chemically highly active and tend to oxidise easily in
the presence of air. In order to prevent these phenomena, it is possible to chemically
stabilize the nanoparticles by the encapsulation of the particles in polymer, silica or
carbon coatings. In the framework of the European research project MEDITRANS, we
synthesized some iron containing nanopowders for biomedical applications by the laser
pyrolysis method. Laser pyrolysis is a very versatile process which allows the synthesis
of a wide range of nanoparticles (carbides, nitrides, oxides, metals and composites
nanoparticles). The method is based on the decomposition of gaseous or liquid reactants
by a powerful CO2 laser radiation followed by a quenching effect. The mixture of
reactants must absorb the radiation of the laser and if necessary an absorber can be added
(as SF6, C2H4 for example). To produce iron containing nanoparticles, iron
organometallic precursors (such as ferrocene and iron acetylacetonate) were solubilised
in various mixtures of solvents. An ultrasonic generator was used to produce an aerosol
of the solution in argon gas. The process parameters (precursors, solvents, gases, laser
parameters) were varied in order to study their effect on the properties of the recovered
nanopowders. All the synthesized powders are black. Examination of the products by
microscopy TEM shows small iron compounds embedded in carbon. X-ray diffraction
gives information on the species encapsulated in carbon. Indeed most of the powders
seem to contain iron metal and/or iron carbide. Only a few samples show the presence of
iron oxide. The addition of C2H4 (absorber) or N2O (oxidizer) tends to strongly increase
the quantity of carbon contained in the powder and therefore wrongly raises the
production rate. Characterization of the magnetic properties and chemical analyses are
ongoing and will be very helpful to determine and optimize the process parameters in
order to fulfil the requirement for MRI and hyperthermia.
A2 – Keynote Paper
METAL OXIDE NANOPARTICLE SYNTHESIS: FROM BINARY
METAL TO MULTI METAL AND DOPED METAL OXIDES
Markus Niederberger, Laboratory for Multifunctional Materials,
Department of Materials, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093
Zürich, Switzerland; [email protected]
10
Surfactant-free nonaqueous sol-gel routes constitute one of the most versatile and
powerful synthesis methodologies for nanocrystalline metal oxides with high
compositional homogeneity and purity. Although the synthesis protocols are particularly
43
simple, just involving metal oxide precursors and common organic solvents, the obtained
nanocrystals are characterized by a wide variety of sizes and shapes, however are rather
uniform and monodisperse within one reaction system. Surfactant-free sol-gel routes in
organic solvents provide several advantages. The small number of reactants on the one
hand makes it possible to study the chemical mechanisms involved in metal oxide
formation. On the other hand, the relatively slow reaction rates facilitate the preparation
of multi metal and doped metal oxide nanoparticles, because it is easier to match the
reactivity of the metal oxide precursors in nonaqueous media than in water. This talk will
give an overview of i) surfactant-free nonaqueous sol-gel routes to binary, ternary, and
doped metal oxide nanoparticles, ii) the basic chemical pathways involved in metal oxide
formation, iii) selected applications, and iv) how microwave irradiation can be used to
shorten the reaction times from days to minutes and seconds.
Session A2 – Contributed Paper
SYNTHESIS OF MANGANESE OXIDE NANOCUBES
Lorette Sicard, Fréderic Herbst, Marie-Josèphe Vaulay, Souad Ammar, JeanYves Piquemal and Fernand Fiévet, ITODYS, Université Paris 7, UMR
CNRS 7086, 2 place Jussieu, 75251 Paris Cedex 05, France;
[email protected]
11
Manganese oxide nanocubes have been obtained by the so-called polyol route. The
synthesis is very simple, without the need of additives, and consists of dissolving
manganese acetate in diethylene gycol and to add water at 100 °C. Before the addition of
water, a rose powder precipitate. This product can be recovered. It has been identified as
a manganese alkoxide, or acetate-alkoxide, with a lamellar-like morphology. The
addition of water allows to obtain the manganese oxide Mn3O4. This brown powder has
an hausmanite structure and is composed of single-cristal nanocubes, monodisperse in
size and measuring 12 nanometer side. The magnetic properties of the oxide were
studied: it is paramagnetic at ambient temperature and becomes ferrimagnetic below 40
K. In the litterature, a confusion is often made between the Curie and the blocking
temperature for the nanocrystals of Mn3O4. Here we confirme by magnetic measurments
that it is a Curie Temperature and that the particles do not exhibit a superparamagnetic
behavior. The change of the synthesis conditions (temperature and pH) allows to tune the
aspect ratio and to obtain nanorods.
Session A2 – Invited Paper
SYNTHESIS OF HIGH PURITY HYDROXYAPATITE NANOPOWDER
BY THE SURFACTANT-ASSISTED AND HYDROTHERMAL METHOD
Xinlong Wang and Ying Zheng, Department of Chemical Engineering,
University of New Brunswick, Fredericton, NB E3B 5A3 Canada;
[email protected]
12
High purity hydroxyapatite nanopowders similar with bone have been successfully
prepared by chemical precipitation followed by low-temperature hydrothermal treatment
using citrate acid as organic modifiers and starting from calcium chloride and trisodium
phosphate. Several techniques including XRD, FTIR, TEM and SAED were used to
44
characterize the as-prepared hydroxyapatite nanopowders. The results indicated that the
purity of the synthesized powders varied with the reactive pH value and the particle sizes
and the crystallinity of the resultant hydroxyapatite nanorods increased with an increasing
autoclaving temperature. The hydroxyapatites obtained at 60°C were fiber-like powders
with weak crystallization and after hydrothermal treatment at 110°C, well crystallized
nanorods (37.6nm×13.3nm) with uniform morphology. The process of crystal growth
was also discussed.
Session A2 – Keynote Paper
TRENDS IN NANOMATERIALS SYNTHESIS AND APPLICATIONS
Richard Brotzman, Patrick Murray, Glenn Judd, and Harry Sarkas,
Nanophase Technologies Corporation, Romeoville, IL 60446, USA;
[email protected]
13
The global adoption rate for nanomaterials continues to increase, not only in the US but
also in Europe and Asia. Successful commercial application development requires each
market be understood and the value proposition of a nanomaterial-based solution
quantified. This is a market environment where nanomaterials compete with other
technologies to bring value to new products.
There are several market realities
• Application success is higher with customer application collaboration
• No one wants nanoparticles in the powder state
• One type of nanoparticle will not provide solutions to all applications
• Commercial quality and quantity is required to participate in the market(s)
• Market success requires nanoparticles, surface engineering, and dispersing
capability
Differences between nanoparticles produced by different synthesis strategies will be
discussed along with applications most appropriate to the specific synthesis method.
NTC’s integrated technology platform – nanoparticle synthesis, surface treatment,
dispersion – will be discussed and market successes in several market segments presented
(personal care, polishing, polymer additives and coatings, textiles). But the production of
high quality dispersions is not enough. NTC has learned the dispersions must be tailored
for specific formulations to achieve the efficacy required for market success. The
specific example of a new family of formulated, nano-alumina based dispersions for
coating applications will be presented. These formulation-tailored dispersions enable the
scratch resistance of water-based coatings to be equal or better than solvent-based
coatings.
DISPERSION AND STABILITY OF TiO2 NANOPARTICULES
SYNTHESIZED BY LASER PYROLYSIS IN AQUEOUS SUSPENSIONS
Carole Sentein, Benoit Guizard, Sophie Giraud, Chang Yé and François
Ténégal, CEA-Saclay,DEN-DANS/DMN/SRMA/LTMEx, Bât.460, 91191
Gif sur Yvette, France; [email protected]
14
45
In the framework of the European Project NANOSAFE2, the development of secure
industrial production systems and safe applications is of major interest. For this goal, we
worked on the development of equipment able to collect in liquids the nanoparticles
produced by gas-phase processes such as laser pyrolysis. Hence, synthesis and liquid
collection of TiO2 nanoparticles was developed on one hand and on the other hand,
dispersion in water and stability of TiO2 nanoparticles synthesized by laser pyrolysis was
studied. In the perspective to recover/collect in water the TiO2 nanoparticles produced by
laser pyrolysis, studies were held to optimize the dispersion and the stability of the
suspensions of TiO2 nanoparticles. The objective is to favour the slurrying of the
nanoparticles in the liquid and to produce stable suspensions for storage and applications.
The influence of different parameters on the dispersion and the stability was studied. The
evolution in time of suspensions for TiO2 nanoparticles with different specific surface
areas was studied. The effect of the free carbon content upon the powder characteristics
was also considered. The effect of the addition of dispersing agents (10 different were
tested) on the suspensions behaviour was measured. Characterization of the particle size
distribution was performed by Dynamic Light Scattering (DLS). DLS measures the
Brownian motion of the particles and relates it to the particle size. Particle size and shape
of the TiO2 nanoparticles were also studied by AFM and TEM. Comparison of the
powder characteristics produced after a dry or a liquid recovery was performed. Specific
surface areas and density are almost the same and the main difference concerns the
carbon content rate which is much higher after a dry recovery. As the TTIP (titanium
isopropoxide), reactant used for the TiO2 synthesis, is very reactive with water, non
pyrolysed part of it may hydrolyses during liquid collection and leads to different volatile
sub-products which disappear during powder recovery. At last, the characteristics
reproducibility for the powders issued from the liquid recovery means was tested. A good
reproducibility was noticed for specific surface area, density and anatase versus rutile
rate.
AN EASY PROCEDURE FOR THE PREPARATION OF
FERROMAGNETIC COBALT NANORODS VIA THE POLYOL
PROCESS: TOWARDS THE FORMATION OF PERMANENT MAGNETS
Yaghoub Soumare,a Jean-Yves Piquemal,a Guillaume Viau,b Thomas
Maurer,c Frédéric Ott,c Grégory Chaboussantc and Fernand Fiévet.a
a
ITODYS, Université Paris 7, case 7090, 2 place Jussieu, 75251 Paris cedex
05, France ; [email protected]; b Université de
Toulouse, INSA, LPCNO, UMR CNRS 5215, 135, avenue de Rangueil,
31077 Toulouse Cedex4, France ; c Laboratoire Léon Brillouin, CEA/CNRS
UMR12, Centre d’Etudes de Saclay 91191 Gif sur Yvette Cedex
15
The preparation of anisotropic metal nanoparticles has attracted many attention because
of their unique properties. Solid templates with nanometer-sized pores, such as anodic
aluminium oxide or polycarbonate membranes prepared by nuclear track etching, have
been widely used, but methods involving the direct precipitation of anisotropic
nanoparticules are highly attractive because they allow, a priori, easy scale-up. In
solution, anisotropic growth is achieved either by addition of a mixture of surfactants that
46
adsorb selectively on different crystallographic faces or by controlling the growth rate of
the different crystallographic planes of the particles. Several studies report the synthesis
of metallic nanowires or nanorods using organometallic complexes but the reaction is
generally carried out under hydrogen pressure for long periods (48 h). nother alternative
is the polyol process which has proven to be an interesting route for the production of
oxide and metal nanoparticles. One of the characteristics of the process is the possibility
of finely adjusting the reaction conditions by the choice of the polyol. Recently, we
reported on the formation of well isolated wires with the composition Co80Ni20 using 1,2butanediol as the solvent. Application of an external magnetic field (H = 10 kOe) at 140
K resulted in the alignment of the nanowires with a very high observed coercive field (6.5
kOe). Given that Co presents a higher saturation magnetization than Ni, the preparation
of anisotropic particles of pure cobalt should lead to materials displaying better magnetic
properties than their alloys. We present a simple, rapid (15 min) procedure for the
preparation of metallic nanorods using the polyol process with heterogeneous nucleation
(Ru) without the need for a solid template. The key parameters are: i) the nature of the
cobalt source and ii) the basicity of the medium. No other surfactant was used in the
course of the synthesis. Transmission electron microscopy reveals that the nanorods have
a mean diameter of 20 nm and a mean length of 100 nm. They crystallize with the hcp
structure, the long axis of the particles being parallel to the crystallographic c axis. They
are ferromagnetic at room temperature and can be aligned by an external magnetic field,
leading to coercivities higher than those of the non-oriented pressed powders. High
coercive fields, up to 9 kOe at 140 K (10 kOe at 5 K) are observed.. Compared to
metallic nanowires prepared with a solid template, the good results obtained here are
explained by the small diameter of the wires and their very good cristallinity. These
results open up new possibilities for the preparation of high-temperature magnets that can
compete with existing permanent magnets such as “AlNiCo” and “SmCo”.
SUPERCRITICAL HYDROTHERMAL SYNTHESIS OF ORGANIC
INORGANIC HYBRID NANOCOLLOIDS
Tadafumi Adschiri, Advanced Institute for Materials Research, WPI, Tohoku
University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan;
[email protected]
16
We propose a new method to synthesize organic-inorganic hybrid nanoparticles at
supercritical hydrothermal conditions. By introducing organic ligands (amino acids,
carboxylic acids, amines, alcohols, aldehydes, etc.) into supercritical hydrothermal
synthesis atmosphere, organic -inorganic hybrid nanocrystals are synthesized. This is due
to the homogeneous phase formation for the organic substance and metal salt aqueous
solutions at supercritical conditions. Particle size is in the range from 2.5 nm to 10 nm,
and particle size dispersion is extremely narrow. Crystal shape can be controlled to be
sphere, nano-cube, nano-ribbon etc. By selecting a proper modifier, particles can be
dispersed perfectly in organic solvents or in aqueous solutions. By drying the colloidal
solution, self-assembly structure of nanocrystals can be obtained. This implies a variety of
applications of the nanoparticles including nanohybrid polymers, nano-ink, nano-paints,
and bio-imaging probe.
47
Session B1 – Keynote Paper
ENCAPSULATION OF DRUG NANOPARTICLES IN SELFASSEMBLED MACROMOLECULAR NANOSHELLS
Michael Pishko, Artie McFerrin Department of Chemical Engineering, 3122
TAMU, Texas A&M University, College Station, TX 77845.
[email protected]
17
A layer-by-layer (LbL) self-assembly technique was used to encapsulate core charged
drug particles in a polymeric nanoshell. This approach provides a new strategy in the
development of polymeric vehicles for controlled release and targeting to diseased tissues
and cells. A nanoshell composed of two biopolymers, poly-L-lysine and heparin sulfate,
were assembled stepwise onto core charged drug nanoparticles. The exterior surface of
the nanoshell was functionalized with biocompatible polymers(poly(ethylene glycol)) and
targeting functional moieties, such as folic acid or protein ligands. Drug nanoparticles of
dexamethasone, paclitaxol, and 5-fluorouracil were fabricated using a modified solvent
evaporation technique, producing particles within a range of 150 to 300 nm. Assembly of
the nanoshell was characterized by zeta potential measurements and XPS. Surface
morphology of the encapsulated drug nanoparticles were viewed by TEM and SEM.
XPS data collected for PEG modified drug nanoparticles confirmed that the peak at 286
eV represented the repeat unit in a PEG molecule. Zeta potential results re-confirmed
PEG’s presence at the surface. Cell uptake studies of PEG modified drug particles were
performed using a flow cytometric assay and suggested that the neutral charge of the
nanoshell results in decreased phagocytosis after 48 hours of incubation. Using
paclitaxel nanoparticles with a breast cancer cell line, the nanoparticiles were found to be
effective in the absence of an excipient such as Cremophor EL. Strategies to create
multifunctional nanoparticles will also be discussed.
Session B1 – Contributed Paper
MICROENCAPSULATION OF ACTIVE NUTRACEUTICAL
INGREDIENTS FOR CONTROLLED DELIVERY
Rachel M. Frazier1, Whitney L. Hough-Troutman2, Daniel T. Daly1, Robin
D. Rogers2,3; 1Alabama Institute of Manufacturing Excellence, University of
Alabama, Box 870204, Tuscaloosa, AL 35487, USA; 2Department of
Chemistry, University of Alabama, Box 870204, Tuscaloosa, AL 35487,
USA; 3School of Chemistry & Chemical Engineering, The Queen's University
of Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK;
[email protected]
18
Controlled delivery of active nutraceutical ingredients (ANIs) has been a hot topic in
recent years as consumers desire continuous sugar release. Blood glucose levels are
subjected to a sudden burst of sugar after a meal, which then levels off as time
progresses. Although many delivery systems are available, they can be complex and
utilize a variety of binders and other inactive ingredients, which may be deleterious to the
digestive system. A relatively simple delivery module has been designed to attach and
48
encapsulate sugars and flavorants, which are then released in an acidic environment
similar to the stomach. Polyetheramines are the basis of the molecular scaffold by which
ANIs are attached via hydrolyzable bonds such as ether, ester, and imine. The molecular
scaffold with attached ANI is then encapsulated into cellulose beads that can be ingested.
The bonds between the ANI and molecular scaffold are then cleaved in an acidic
environment to release the ANI, chemically unchanged and without additional release of
any by products. This process also utilizes the reusable and renewable resources of
cellulose, ethanol, and polypropylglycol that allow this to be a viable industrial process.
We have demonstrated controlled release of ANIs in acidic solution of pH ~ 2. The ANIs
are released after approximately 200 minutes. When compared to the hydrolysis of the
bonds from the molecular scaffold alone, this is 30 times slower to release into solution.
This demonstrates the effectiveness of the bead encapsulation of the molecular scaffold to
provide continuous release of ANIs. The controlled release of ANIs and the dependence
on process variables will be presented.
Session B1 – Invited Paper
ENCAPSULATION PROPERTY OF UNIMOLECULAR NANOCAPSULE
BASED ON HYPERBRANCHED POLYMER
Toshifumi Satoh, Graduate School of Engineering, Hokkaido University,
N13W8, Sapporo 060-8628, JAPAN; [email protected]
19
The novel unimolecular nanocapsule consisting of hyperbranched carbohydrate polymer
(1) as a core and L-leucine ethyl ester as the shell was synthesized by the reaction of 1
with the N-carbonyl L-leucine ethyl ester. The carbamation reaction was found to be a
convenient method for preparing the organic solvent-soluble amphiphilic hyperbranched
carbohydrate polymer (2). The encapsulation ability of 2 toward water-soluble dyes has
been investigated by UV-vis and CD measurements in chloroform. These results
indicated that 2 was a unimolecular nanocapsule with an encapsulation ability toward
hydrophilic dye molecules, such as rose bengal. In addition, the rose bengal encapsulated
in 2 showed a slow release, and its release rate was extremely accelerated under basic
conditions. Hence, 2 was a good candidate for pH-sensitive controlled-release systems,
and the encapsulation-release property of 2 possibly provides a strategy for designing
new drug delivery systems.
NANOENCAPSULATION VIA INTERFACICALLY CONFINED
REVERSIBLE ADDITION FRAGMENTATION TRANSFER (RAFT)
MINIEMULSION POLYMERIZATION
Yingwu Luo, The State Key Laboratory of Chemical Engineering,
Department of Chemical Engineering and Bio-Chemical Engineering,
Zhejiang University, Hangzhou 310027, China;
[email protected]
Nanocapsules of functional substances have shown promising applications in the area of
drug delivery, catalysis, dye dispersion, optical medium, data storage, and so on. Many
20
49
different innovative technologies of nano-encapsulation have been developed recently.
Most of these technologies are of low efficiency or difficult to scale up due to involving
complicated many-step procedures such as repeated centrifugation or filtration, core
removal and re-filling or involving a very dilute system. In view of large-scale practical
applications, it is very desirable to have a versatile approach of nano-encapusulation with
high efficiency. We invented a general strategy of nanoencapsulation of liquid substance
by the interfacially confined RAFT miniemulsion polymerization, which is high efficient,
environmentally benign, and easy to scale up. An amphiphilic RAFT oligomer was
designed and used as a surfactant to prepare miniemulsion (oil droplets of 50~500nm
dispersed in water). Due to their amphiphilic properties, the amphihilic RAFT molecules
will self assemble on the interface of water/droplets once miniemulsion is formed via
ultrasonication. When a water-soluble initiator like potassium persulfate (KPS) is
introduced, water-soluble primary radicals are born in the water. After several additions
of monomer, the oligoradicals become surface active and are captured by mini-droplets.
The surface-active radicals with anionic head groups are anchored on the interface of
mini-droplets and water. Since the RAFT agent molecules are also anchored on the
interface, the radicals would transfer among the RAFT agents via RAFT reactions. By
this way, the radical is located at the interface during most of polymerization time, so the
polymerization is confined on the interface. The polymer chains would grow inwards
gradually, leading to the formation of a polymer shell. The approach will be
demonstrated in synthesizing a variety of nanocapsules with different core materials
(phase change materials, dyes), shell properties (crosslinked, Tg), and capsule sizes and
its distributions (uniform in size). The key parameters controlling the formation of the
nanocapsules were identified. This work is financially supported by NSFC (#20474057).
SYNTHESIS OF MONODISPERSE PARTICLES AND CAPSULES BY
SUBMERGED INKJET-PRINTING
Marcel Böhmer, Jan Steenbakkers and Ceciel Chlon, Biomolecular
Engineering, Philips Research, NL, [email protected]
21
Monodisperse microparticles of biodegradable polymers of a controlled size and
composition were synthesized using a drop on demand inkjet nozzle operating at 24,000
Hz, jetting monodisperse emulsion droplets into an aqueous solution of poly-vinyl
alcohol. These emulsion droplets were converted to polymer particles by selective
removal of the carrier solvent. The polymer concentration in the ink and emulsion droplet
size determine the final particle size. Inclusion of alkanes leads to the formation of
polymer-shelled oil-filled capsules and the subsequent removal of the alkane gives
monodisperse hollow particles that can be activated with ultrasound to release their
contents. To include hydrophilic, high molecular weight drugs into such particles double
emulsion techniques are applied. Ink-jetting a first emulsion instead of a homogeneous
solution leads to exactly the same particle size as inkjetting the pure polymer solution at
the same concentration, indicating that all the water incorporated in the first emulsion is
extracted. As particle sizes obtained with this techniques are highly predictable
submerged inkjet-printing can be used effectively to study polymer combinations, the
swelling of hydrogels and incorporation efficiencies of high molecular weight drugs.
50
INCORPORATION IN POLYMERIC NANOCAPSULES IMPROVES THE
ANTIOXIDANT EFFECT OF MELATONIN AGAINST LIPID
PEROXIDATION IN MICE BRAIN AND LIVER
Scheila R. Schaffazicka, Ionara R. Siqueirab, Alessandra S. Badejoa, Denise S.
Jornadaa, Adriana R. Pohlmanna,c, Carlos Alexandre Nettod,, Sílvia S.
Guterresa*; a Programa de Pós-Graduação em Ciências Farmacêuticas,
Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto
Alegre (UFRGS)-RS, Brazil; b Departamento de Farmacologia, Instituto de
Ciências Básicas da Saúde (UFRGS)- Brazil; c Departamento de Química
Orgânica, Instituto de Química (UFRGS)- Brazil; d * Departamento de
Bioquímica, Instituto de Ciências Básicas da Saúde (UFRGS)- RS, Brazil;
[email protected]
22
It has been recently shown that the association of melatonin with polymeric nanoparticles
causes a significant increase of the in vitro effect against lipid peroxidation. Hence, the
aim of the present study was to compare the in vivo acute antioxidant effect of
intraperitoneal administration of melatonin-loaded polysorbate 80-coated nanocapsules
with that of melatonin aqueous solution in mice brain (frontal cortex and hippocampus)
and liver. The lipid peroxidation through thiobarbituric acid reactive substance levels, the
total antioxidant reactivity (luminol-enhanced chemiluminescence) and the free radical
levels (formed dichlorofluorescein) have been carried out. Our results show that a single
melatonin aqueous solution injection exerted no antioxidant activity in the evaluated
range, while the administration of the melatonin-loaded polysorbate 80-coated
nanocapsules caused a marked reduction on lipid peroxidation levels in all studied
tissues. No differences on free radical content were found in the tissues. The melatoninloaded nanocapsules also increased the total antioxidant reactivity in the hippocampus.
These in vivo results are in accordance with our previous in vitro findings and confirm
the hypothesis that polymeric nanocapsules improve the antioxidant effect of melatonin
against lipid peroxidation.
REVERSE PHASE LAYER-BY-LAYER POLYELECTROLYTE SELF
ASSEMBLY ENCAPSULATION OF WATER SOLUBLE
MICROPARTICULAR MATERIALS
Sebastian Beyer1, Mak Wing Cheung2, Marten Werner3, Dieter Trau2, 4 ,*;
1
Gelsenkirchen University of Applied Sciences, Germany; 2Division of
Bioengineering, National University of Singapore, Singapore,
[email protected]; 3Lund University, Sweden; Department of Chemical &
Biomolecular Engineering, National University of Singapore, Singapore;
*presenting and corresponding author; all authors contributed equally
23
We report on a novel method for the encapsulation of highly water soluble
microparticular materials by using Reverse Phase Layer-by-Layer (LbL) polyelectrolyte
self assembly. Until now LbL polyelectrolyte self assembly coating and encapsulation
51
methods were only applicable to none or poorly water soluble materials. Our method
extends the material spectrum for the first time into highly water soluble materials
including drugs, vitamins and other compounds with potential applications in
Bioengineering. By using our novel method Reverse Phase Layer-by-Layer (LbL)
polyelectrolyte self assembly we have demonstrated the direct encapsulation of crystals
of proteins, insulin, carbohydrates, vitamins, organic and inorganic salts. The method is
simple and robust and applicable to a broad range of substances. Typically applications of
this new method can be the protection of enzyme sensitive highly water soluble drugs by
the nanometer thick capsule membrane, a controlled release of the template material,
coatings for biomaterials. Advantages of this new method are for example the very high
encapsulation efficiency for microcrystals or other microparticular materials as well as
for gel-beads with entrapped water soluble substances and the creation of powders and
solids of encapsulated materials. Multilayer deposition was proven, layer thickness was
determined by Atomic force microscopy and the releases of several encapsulated
substances with potential applications in drug delivery were studied.
LAYER-BY-LAYER ASSEMBLY ON GOLD NANOPARTICLES
Emek Seyrek, Gregory Schneider, Gero Decher; CNRS - Institute Charles
Sadron, 23 Rue du Loess, BP 84047, Strasbourg 67034, France;
[email protected]
24
Methods for preparation and characterization of core/shell gold nanoparticles (AuNPs)
using electrostatic layer-by layer (LbL) assembly will be presented. Different gold cores
were prepared with sodium citrate or L-ascorbic acid as the reducing agent, which
required different parameters for LbL deposition. LbL was performed by sequential
deposition of cationic and anionic polyelectrolytes, utilizing centrifugation and/or
ultrafiltration techniques. The polyelectrolytes employed were polyallylamine
hydrochloride (PAH), polystyrene sulfonate (PS) and dextran sulfate (DS). The
parameters that effect the efficiency and reproducibility of the methods, i.e. the
concentration of reducing agent for AuNP synthesis, type and concentration of
polyelectrolytes, concentration of AuNPs, parameters of centrifugation and ultrafiltration,
will be discussed in detail. The current challenges and future potential applications for
these core/shell AuNPs will also be presented.
Session C1 – Invited Paper
DIRECTED ASSEMBLY WITH NANOPARTICLE SYSTEMS
Kevin Yager, Jason Benkoski, Eric J. Amis, and Alamgir Karim, Polymers
Division, NIST, Gaithersburg, MD 20899, USA; [email protected]
25
The use of functional nanostructured and nanofilled polymer films as templates for
advanced lithography, solar cell films or nanoporous membranes, is limited by
prohibitively long time required for defect annihilation, and the typically stringent
preparation conditions. We have previously reported some of our work on directed self-
52
assembly methods for block copolymers that include thermal gradient zone annealing,
environmental vapor spin-coating, and physically confining and chemical patterned
substrates. This talk will describe a new approach, the facile directed assembly of blockcopolymer of PS-PMMA using a nanoparticle coating cast on silicon substrates. The
partial substrate coverage and average surface energy of the coating are loosely
controlled to achieve a near-neutral condition for both blocks. This strategy combines the
topographically disrupting effect of nanoparticles on block-copolymer surface ordering
with competitive surface wetting energetics for the blocks to achieve parallel and
perpendicular orientations. Finally, the self-assembly characteristics of the cast
nanoparticles are compared to the nearly unperturbed state at a liquid-liquid interface.
Session C1 – Contributed Paper
FORMATION OF HIGHLY ORDERED ANISOTROPIC NANOPARTICLE
SUPERLATTICES BY SELF-ASSEMBLY ON WATER SURFACES
Takuya Harada and T. Alan. Hatton, Department of Chemical Engineering,
Massachusetts Institute of Technology, Cambridge, MA 02140, USA
[email protected]
26
The establishment of well defined methods for the fabrication of highly ordered, twodimensional nanoparticle assemblies (superlattices) is crucial if various future
applications based on functional nanoparticles are to be realized. We report here on the
self-assembly of nanoparticles on liquid surfaces as a potential approach for the
generation of homogeneous, relatively defect-free, large-area, nanoparticle films, and
explore means for the facile control of the self-assembled nanoparticle layer properties.
We have shown that a peculiar, planar anisotropic, highly ordered nanoparticle
superlattice is formed when the colloidal dispersion of magnetic (such as Fe3O4)
nanoparticles is dried on the water surface under certain controlled conditions. In this
presentation, we will detail the experimental conditions under which these anisotropic
nanoparticle superlattices are formed, and discuss possible mechanisms for the formation
of such anomalous self-assembled nanoparticle layers.
LARGE DNA-BASED PARTICLES FROM OLIGONUCLEOTIDE
HYBRIDS WITH ORGANIC CORES
Martin Meng, Matthias Bauer, Oliver Plietzsch, Carolin Ahlborn, Shahid
Soomro, Thierry Muller, Stefan Bräse, Wolfgang Wenzel, and Clemens
Richert; University of Karlsruhe and Forschungszentrum Karlsruhe, 76131
Karlsruhe and 76344 Eggenstein-Leopoldshafen, Germany; [email protected]
27
Small nanoparticles of defined three-dimensional structure can be formed through the
programmed, sequence-specific assembly of short DNA strands. The extension of this
concept to large nanoparticles of > 100 nm diameter, let alone macroscopic crystals has
proven challenging. To date, no designed crystals, generated through base pairing
between complementary nucleic acid strands have been reported. We have initiated a
research program focused on the assembly of oligonucleotides covalently linked to
organic core molecules. As a first example, we present DNA-based assemblies of sub53
micrometer size that are generated through hybridization in aqueous buffer. These were
characterized by electron microscopy and spectroscopic techniques. Another sequence
was found to assemble into an insoluble solid upon cooling in aqueous solution.
SYNTHESIS AND SELF-ASSEMBLY OF GOLD NANORODS
Eugene R. Zubarev, Department of Chemistry, Rice University, Houston,
Texas 77005, USA; [email protected]
28
Gold nanorods exhibit strong optical scattering and absorption in the visible and nearinfrared regions due to the localized surface-plasmon resonance. The longitudinal
plasmon of gold nanorods is dependent on their aspect ratio. However, the nanorods
synthesized by classical seed-mediated method have a very limited range of achievable
aspect ratios (3-5). Numerous attempts to increase the aspect ratio to values greater than 5
have met little success so far. This presentation will describe methods to tune the
plasmon peak in a reversible fashion and obtain nanorods with any aspect ratio ranging
from 1 to 200. One-dimensional growth and shortening of nanorods in aqueous solution
in the presence of Au (I) and Au (III) ions, respectively, will be discussed. Self-assembly
and the preparation of the periodic arrays of nanorods from organic and aqueous
solutions will be discussed as well.
LIPID TUBULES WITH BIREFRINGENT CORES AND THEIR
ORDERED ARRAYS
Jiyu Fang, Advanced Materials Processing and Analysis Center and
Department of Mechanical, Materials, and Aerospace Engineering, University
of Central Florida, Orlando, FL 32816, USA; [email protected]
Self-assembled lipid tubules with crystalline bilayer walls are supramolecular
architectures. By filling lipid tubules with nematic liquid crystals, we have formed optical
anisotropic fibers. Due to the tunable refractive index of namatic liquid crystals, the lipid
tubules with liquid crystal cores might have potential applications in sensors, photonic
devices, and optical communications. We have shown that 2-D ordered arrays and 3-D
cross-bar junctions of the lipid tubules with liquid crystal cores can be fabricated on a
verity of substrates by confined dewetting, microfluidic networks, and microcontact
printing. The ability of fabricating lipid tubules into ordered arrays is an important step in
integrating them with functional devices.
29
ARRAYS OF CARBON NANOTUBES COATED BY NANOPARTICLES
OF METALS AND METAL-OXIDES
Emanuela Tamburri, Silvia Orlanducci, Francesco Toschi, Valeria
Guglielmotti, Maria Letizia Terranova, Università di Roma “Tor Vergata”,
Dip.to Scienze e Tecnologie Chimiche and MINASlab,Via della Ricerca
Scientifica, Roma, 00133, Italy; [email protected]
30
Ordered arrays of carbon nanotubes (CNTs) have been utilized as a suitable platform for
the growth of nickel nanoparticles and nanocrystalline metal-oxide. The CNTs systems
54
have been prepared following two different methodologies. In a case, well organized
CNTs arrays have been grown on a Si substrate by Chemical Vapour Deposition (CVD)
techniques whereas in the other case the CNTs have been opportunely aligned on a
multifinger interdigitated electrode via a dielectrophoretic post synthesis process. The
metal-oxide coatings (TiO2, Ta2O5, ecc) have been realized during the CVD growth
process of nanotubes. The nickel nanoparticles have been deposited on the CNTs arrays
by means of electrochemical methods. In this case the ordered arrays of CNTs on the Si
and on the multifinger substrates act as electrode surface for the electro-reduction of the
metal. The morphology and structure of the Ni-coated CNT bundles have been
characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and X-Ray
diffraction (XRD). By changing the parameters of the electrochemical process, it is
possible to modulate the morphological characteristics of the Ni deposits, which can be
obtained in form of nanoparticles uniformly distributed along the whole length of the
CNT bundles. A detailed study of the nucleation mechanism of Ni onto CNT has been
performed using transient current technique and a correlation between growth mechanism
and samples morphology is presented and discussed. The possibility to maintain the
architecture of the pristine nanotube deposits after the Ni coating process opens new
perspectives for integration of CNT/Ni systems in magnetic and spintronics devices.
Moreover the metal-CNTs systems could have some interesting applications as protective
coatings against corrosion and electrochemical detection of traditional “nonelectroactive” amino acids.
SURFACE PATTERNING USING INTERFACIAL COLLOIDAL
CRYSTALS
Li Jia, Department of Polymer Science, University of Akron, Akron, OH
Charged colloidal particles experience long-range electrostatic repulsion at the air-water
interface. Within a confined space, the monodisperse spheres form 2-dimensional
hexagonal crystals with the adjuestable lattice constant by the surface pressure. Such
interfacial films are difficult to be transferred onto a solid substrate with the order intact
because the noncontiguous particles in the films can be easily moved out of their lattice
positions. This presentation will describe a process that allows the transfer of the
hexagonal non-contiguously packed (HNCP) interfacial colloidal crystal onto a solid
substrate. The process requires the optimization of the attractive forces between the
colloidal particles and the substrate and the minimization of the water-wettability of the
substrate surface. After the initial transfer, manipulations to minimize the destructive
capillary force or to improve adhesion are sometimes necessary to secure the particles in
their lattice positions. The resulting pattern on the solid substrate possesses long-range
order on the square millimeter scale. Two particle systems will be discussed, the 258 nm
positive particles and the 2.7 mm negative particles. Depending on the particle size and
periodicity, the patterned surfaces display diffractive or antireflective properties.
31
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Session D1 – Keynote Paper
NANOPOWDER SURFACE CHARACTERIZATION
Ian Morrison and Ani Nikova, Cabot Corporation, Billerica MA 01821,
USA; [email protected]
32
Many nanoparticles are most interesting when dispersed in a medium such as a liquid or a
polymer. For these, understanding interfacial interactions is key to advancing the
technology. Typically, predicting interfacial interactions is sought by measuring surface
chemistry and surface morphology, particularly surface area. In principle, statistical
thermodynamics tells us how to estimate interfacial interactions from the properties of the
particle surface and the medium. In practice, predictions have been illusive and only
correlations are the result, loosing the advantage of detailed surface analysis. For flat
surfaces useful progress has been made by measuring contact angles of liquids of known
surface tensions on solids of interest, primarily low surface energy polymers. It has been
found that measuring the interfacial interactions for a few, carefully selected materials
gives information to predict the interactions with other media. This is the idea behind
characterizing surfaces with dispersion-energy and Lewis acid-base components. Contact
angles on nanopowders cannot be measured by observation. We find that a fruitful
method is to measure the gas adsorption isotherm over the full range of vapor pressure up
to the vapor pressure of the liquid. As is well known, when the liquid has a finite contact
angle with the solid, then the integral of the data gives the spreading pressure. The
contact angle is still unknown. It is certainly likely that the greater the spreading pressure,
the lower the contact angle. This is a hint. If liquids that interact strongly with the
nanopowder surface are measured, the contact angle is zero (the liquid spreads). The
integral of this data (plus the liquid surface tension) is the work of adhesion. We easily
measure the work of adhesion on any (nonvolatile) nanopowder with several stronglyinteracting liquids. The use of dispersion-energy and Lewis acid-base theories to predict
interfacial interactions are now practicable and verifiable; a goal not previously attained,
even for systems with observable contact angles.
Session D1 – Contributed Paper
ZETA POTENTIAL CHARACTERIZATION OF PARTICLES IN
SUSPENSION
Ren Xu, Particle Characterization, Beckman Coulter, Inc., 11800 SW 147
Ave., Miami, FL 33116-9015, USA, [email protected]
33
Zeta potential measurement of particles in suspension is a very important research tool
and quality control means for dispersion stability and product performance of nano or
submicron particulate materials. There are two technologies that are commonly used for
zeta potential measurement, i.e., electrophoretic light scattering (ELS) and acoustic. The
ELS technology produces accurate and high resolution results for both aqueous and nonaqueous suspensions. However, its current applications are limited to dilute samples due
to the conventional optical arrangement. On the other hand, the acoustic technology can
only measure zeta potential of concentrated samples and provides only average zeta
potential with low sensitivity and low resolution. In this presentation, a novel technology
(FST) used for ELS measurement is introduced. In the patented FST technology,
56
measurements are performed on particles near the electrode therefore avoiding multiple
scattering and scattering attenuation due to high solid concentration. Combined with
photon correlation spectroscopy (PCS) measurement capabilities, this new generation of
zeta potential and particle size measurement instrument from Beckman Coulter
demonstrates that it can perform both size and zeta potential measurements for
polystyrene latex suspensions covering four decades, ranging from 0.001% to 10% of
solid concentration and obtain concentration independent results for both particle size and
zeta potential. This instrument can also measure dilute samples or small scatterers with
unprecedented sensitivity, sizing 0.6 nm Thiamin molecules (Mw~337 Dalton), and
resolution, distinguishing generation 3 dendrimer with generation 5 dendrimer.
Session #
THE REAL-TIME, SIMULTANEOUS ANALYSIS OF NANOPARTICLE
SIZE, ZETA POTENTIAL, COUNT, ASYMMETRY AND
FLUORESCENCE IN LIQUIDS
Bob Carr, Patrick Hole, Andrew Malloy, Jonathan Smith, Andrew Weld and
Jeremy Warren, NanoSight Ltd, Salisbury, UK; [email protected]
A new nanoparticle sizing and characterization technique is described which allows
nanoparticles in a suspension to be individually but simultaneously detected and analysed
in real time using a low cost instrument. Nanoparticles of all types and in any solvent can
be detected, sized and counted through video-based tracking of their Brownian motion
when illuminated by a specially configured laser beam. Depending on particle type,
nanoparticles as small as 10nm can be visualized (though not imaged). The technique is
robust and low cost representing an attractive alternative or complement to higher cost
and more complex methods of nanoparticle analysis such as photon correlation
spectroscopy (PCS) or electron microscopy that are currently employed in a wide range
of technical and scientific sectors. The technique uniquely allows the user a simple and
direct qualitative view of the sample under analysis (perhaps to validate data obtained
from other techniques such as PCS) and from which an independent quantitative
estimation of sample size, size distribution and concentration can be immediately
obtained. Examples of analyses of a wide range of sample types will be shown including
nano-emulsions from pharmaceutical and clinical applications and metal oxides and
nano-ceramics from the chemical, pigments and coatings industries. Advances in the
technique will be described which allow each particle to be simultaneously analysed not
just in terms of its size but also light scattering power (mass/refractive index) from which
3D plots of size v. tight scatter can be produced. Similarly, through the addition of
electrodes in the device head, charged particles can be identified through their
electrophoretic mobility, from which an estimate of zeta potential can be obtained on a
particle-by-particle basis. Importantly, a mixture of negatively and positively charged
particles can be resolved, each particle being simultaneously analysed in terms of its
Brownian motion-derived size and scattered intensity. Furthermore, preliminary results
will be presented that show an unprecedented ability to identify nanoparticle asymmetry
in real time, again on a particle-by-particle basis and simultaneously linked to the
parameters described above. Finally, by employing suitably shorter wavelength optical
sources it is possible to excite fluorophores attached by antibodies, for instance, to
specific types of biological nanoparticle. Accordingly, a wide range of fluorophores
34
57
currently employed in conventional flow cytometry for phenotyping cell lines and other
biological particles, is currently being tested and which show promise as labels of
sufficient efficiency to allow real time monitoring of biological microparticles at video
frame rates. It should be noted that it remains possible to simultaneously determine
nanoparticle size and surface charge under fluorescence analysis. In conclusion, the
technique will uniquely offer a real-time, simultaneous multiparameter analysis (size, Ri,
zeta potential, count and shape factor) of individual nanoparticles in suspension. The
inclusion of a fluorescence capability significantly enhances the technique. This
capability would, in effect, extend the current flow cytometric capability down one order
of magnitude while uniquely adding a particle surface charge analysis.
Session D1 – Invited Paper
ULTRASOUND FOR CHARACTERIZING NANO-COLLOIDS: SIZING,
ZETA POTENTIAL, RHEOLOGY.
A.Dukhin and P.Goetz , Dispersion Technology Inc., 364 Adams Street,
Bedford Hills, NY 10507 , USA; [email protected]
35
The scope of this talk includes description of several analytical techniques, which employ
ultrasound for extracting information about the properties of nano-colloids. Ultrasound
can propagate through samples that are not transparent for light, which open up many
new applications not possible with classical light scattering methods. These ultrasound
techniques offer a unique opportunity to characterize concentrated nano- and micro
dispersion, emulsions and micro-emulsions in their natural states. Elimination of a
dilution step required for most other techniques (light scattering, sedimentation,
electrophoresis) is crucial for an adequate characterization of liquid heterogeneous
systems, especially when the high concentration leads to structured systems. As with any
macroscopic method, ultrasonic techniques characterize the sample in two steps. The first
step is measurement of particular macroscopic property, which might be ultrasound
attenuation, or sound speed, or electroacoustic signal. These raw data can be interpreted
initially on phenomenological level. Acoustic spectrometer at this point can be
considered as Acoustic Rheometer. We present phenomenological link between
Acoustics and Rheology, and various applications, including characterization of chemical
relaxation in homogeneous fluids, Newtonian fluid test, measurement of bulk viscosity.
Longitudinal visco-elastic modulus can be used as system fingerprint similarly to the
traditional shear visco-elastic modulus. There is possibility of the second step in the raw
data theoretical interpretation. It would involve appropriate microscopic model of
heterogeneous system, like separate spherical particles in Newtonian liquid. Alternatively
it could be model of particles bounded into a network. Theoretical treatment allows
extraction information on particle size, zeta potential, micro-rheological properties. We
briefly discuss existing theories and concentrate more attention on the nanotechnology
applications.
58
CHARACTERIZATION OF PARTICLE DISTRIBUTION AND
ORIENTATION IN SOLID MEDIA
Miran Mozetic, Plasma Laboratory, Jozef Stefan Institute, Jamova cesta 39,
1000 Ljubljana, Slovenia; [email protected]
36
A method for determination of particle distribution in solid media is presented. The
method is based on selective etching of the solid medium from the surface of the object
composing small particles distributed in the medium. The method performs best for
characterization of objects made from any particles distributed in organic (often polymer)
matrix. Samples are mounted in a vacuum chamber and exposed to a flux of oxidizing
radicals, often neutral oxygen atoms in the ground state. The source of the atoms is
weakly ionized highly dissociated plasma created in an inductively coupled radiofrequency discharge. Oxygen atoms react with the organic matrix even at room
temperature causing slow etching of the matrix while leaving the particles intact. The
etching rate depends on the treatment time and the flux of atoms, and is typically about a
minute. After the treatment, the surface layer of organic material is removed and the
particles become visible. The object is then imaged by a scanning electron microscope.
Since the etching is performed at room (or slightly elevated) temperature, and since the
particles do not react with oxygen atoms, the original distribution is preserved. The
method is used routinely for characterization of polymer matrix composites. Several
examples of application are presented ranging from bulk materials to coatings with an
emphasis on different paints.
HIGHLY STABLE SUSPENSIONS OF METAL OXIDE
NANOPARTICLES
Ali Bumajdad and Asha Mathew, Kuwait University, Faculty of Science,
Chemsitry Department, P.O. Box 5969 Safat 13060, Kuwait;
[email protected]
37
Highly dispersed nanoparticles of variety of pure- and mixed-metal oxides (namely
Fe2O3; CeO2; CuCeO2; KCeO2; MgCeO2; NiCeO2; TiO2; and Cr2O3) were prepared using
water-in-n-heptane microemulsion as template and stabilizing media. The employed
surfactants were mixture of the cationic di-n-dodecyldimethylammonium bromide,
DDAB, and the nonionic is polyoxyethylene 23 lauryl ether, Brij®35, at molar ratio
equal 9:1. The effect of different variables on the suspension stability will be explained.
Focus will be given to microemulsion droplet concentration, droplet size, nanoparticles
concentration, and type of precipitating agent. Using SEM, HR-TEM, AFM, XRD, XPS,
Viscometer, DSC, FT-IR, UV and other techniques, the properties of the nanoparticle
suspensions (e.g. stability, amount stabilized, viscosity, etc.) and nanopowders (e.g. size,
polydispersity, shape, crystallinity, composition, etc.) were studied and correlated with
amount of surfactants used and water-to-n-heptane molar ratio. It is worth mentioning
that such suspensions and powders have industrial applications like additives to coating
and lubricant and also can be used as a catalyst.
59
ORTHOGONAL TRACKING MICROSCOPY FOR NANOFABRICATION
RESEARCH
Matthew D. McMahon, Andrew J. Berglund, Peter Carmichael, Jabez J.
McClelland, J. Alexander Liddle; Center for Nanoscale Science and
Technology, National Institute of Standards and Technology, Gaithersburg,
MD 20899, USA; [email protected]
38
Particle tracking in two lateral dimensions by digital video microscopy can be
implemented in a straightforward manner by the use of centroid algorithms. Obtaining
position information in the out-of-plane dimension has been more difficult, typically
requiring fitting to complicated Airy patterns. We introduce a technique called
orthogonal tracking microscopy, in which we use micromirrors integrated with the
sample to project a side-on view of the region of interest. The mirrors project vertical
motion into lateral motion, allowing us to obtain full three-dimensional tracks from
purely two-dimensional images using simple centroiding, and with vertical resolution
comparable to lateral resolution.
FT-IR AND DIFFUSE REFLECTANCE FT-IR FOR QUANTITATIVE
DRUG LOAD ESTIMATION IN ALGINATE NANOCAPSULES WITH
TESTOSTERONE PAYLOAD
Arup Mukherjee and Benoy B. Bhowmik, Division of Pharmaceutical &
Fine Chemicals Technology, Department of Chemical Technology, Calcutta
University, 92,A.P.C. Road, Kolkata- 700009,India; [email protected]
39
Precise quantization of drug load in nanoparticle delivery devices have often suffered for
multiple of factors. Large preparation batch to batch variations are a reality and complete
dissolution requirements for drug molecules in interactive polymer colloid environment is
in itself a dynamic inaccuracy. Additionally, the drug being present in a multi -chemical
environment often require destructive sample dissolution treatments, chromatography or
dialysis separation before any load estimation can actually be made. Transmittance FTIR and Diffuse Reflectance FT-IR (DR FT-IR) are powerful tools for accurate and
nondestructive evaluation of a chemical component even when it is present in a complex
physical mixture. The estimation is dependent upon fundamental vibrations due to
specific functional groups and can be performed on a routine basis. This work deals in
synthesis of steroid drug testosterone loaded hydro polymer alginate nanocapsules
followed by, drug pay load estimation in FT-IR, DR FT-IR and in HPLC. Nanocapsules
were prepared in a nano-emulsion, polymer cross linking technique and particles
visualized in transmission electron microscopy (TEM). Particles appeared spherical and
in uniform coating in TEM micrographs. Photon correlation spectroscopy, PCS, diameter
was observed 35nm, zeta potential – 5.2 and polydispersity 0.22. Differential scanning
calorimetery, DSC, studies confirmed nanocapsules testosterone payload with specific
endotherm appearing at 1510C independent of polymer decomposition response at 2920C.
In KBr pellet, FT-IR, testosterone responded with CH2 stretching at 2939cm-1, alcoholic
60
OH band at 3395cm-1 and characteristic C=O vibrations at 1665cm-1 with aldehydic C-H
stretching at 2874cm-1 and similar observations were corroborated with somewhat
flattened OH vibration response in DR FT-IR gatherings. In FT-IR drug load quantization
experiments, concentration versus absorbance standard graph were first drawn for
testosterone C=O vibrations peak height ratio, against weighed drug concentration range.
Base points were taken at 1720± 2.5 cm-1 and 1626± 2.5 cm-1. Validated JASCO QAU400 quantitative analysis suite software was used throughout accumulating 245 scans for
each pure testosterone concentration points. Testosterone pay loaded alginate
nanocapsules were then sampled and absorbance due to C=O vibrations were used for
estimation of drug load. In parallel experiments, testosterone pay loads in nanocapsules
were evaluated in DR FT-IR following Kubelka-Munk transform and in HPLC after
dissolving the polymer coat in 1 % w/v sodium citrate solution. The drug load appeared
30.2% in HPLC and 31.2% in FT-IR quantization. FT-IR can be routinely used for
precise and non destructive drug payload studies in nano-drug delivery devices.
Session E1 – Keynote Paper
TRANSPARENT, POLYCRYSTALLINE UPCONVERTING
NANOCERAMICS: TOWARDS 3-D DISPLAYS
Thomas R. Hinklin, Stephen C. Rand and Richard M. Laine, University of
Michigan, Ann Arbor, MI. 48109-2136, USA; [email protected]
40
We describe here the concept of a 3-D display wherein arrays of transparent upconverting
phosphor pixels are formed in a 3-D hollow shape. This shape is then illuminated from
within with a rastered IR source which in turn upconverts the IR to red, green and blue
light in an “inverse planetarium” format to provide 3-D images. To realize such a display,
one of the key steps must be the ability to produce transparent polycrystalline pixels. We
report here the production of (Y0.86Yb0.11Er0.03)2O3 and (Y0.929Yb0.070Tm0.001)2O3
composition nanopowders, their characterization and processing to transparent,
polycrystalline red and blue upconverting phosphors. The initial powders exhibit the
cubic phase of yttria, and consist of unaggregated, single crystals with average particle
sizes <50 nm that are readily compacted to green densities of 60-63 % of theory. Binder
burnout on heating to 800°C in air, vacuum sintering to 1350°-1450°C and HIPping at
similar temperatures at 140 MPa provides dense pellets with average grain sizes of ≈ 400
nm and up to 70 % transparency. These materials effectively unconvert 980 nm IR light
to visible light (e.g. 662 nm for Er doped material) and offer the potential to serve as
pixel materials for the proposed “inverted planetarium” 3-D display.
Session E1 – Invited Paper
PARTICLES ON THE BEACH: THE DREAM OF ELECTRONIC PAPER
Tanya Z. Kosc; Laboratory for Laser Energetics, University of Rochester,
Rochester, NY 14623, USA; [email protected]
41
It has been over a decade since a post-doc sat on a sunny California beach and wished he
didn’t need to lug all his books with him. In the following years, he sowed the seeds for
E-Ink, and many electrophoretic particle display technologies, including SiPix, have
61
followed suit. The unique Gyricon technology was revived after decades on the shelf,
only to run into commercialization difficulties. A new concept of Quick Response Liquid
Powder Displays suddenly emerged from labs and continues to make headway. With PInk, particles form photonic crystals, and a completely novel approach is being
developed. Scores of innovative technologies continue to emerge from research facilities
around the world, where funding or the lack there of, plays a crucial role in their potential
for development. This talk will offer a brief look at the history of particle-based display
technologies, and describe the current state of the art.
Session E1 – Contributed Paper
MODIFICATION OF PIGMENT SURFACE WITH ACRYLIC
COPOLYMERS FOR MICROCAPSULE-BASED ELECTROPHORETIC
DISPLAY
In-Joo Chin, Hyun-Ryool Woo, Jung-Hyun Yun, Yong-Ku Kwon, and
Hyoung-Jin Choi, Dept. of Polymer Science and Engineering, Inha
University, Incheon 402-751, Korea; [email protected]
42
To realize the microcapsule-based electrophoretic displays, the individual pigment
particles should be dispersed in the dielectric fluid. In this study, titanium dioxide (TiO2)
nanoparticles and charged color organic pigment nanoparticles were modified with acryic
copolymer to improve the dispersion stability of the nanoparticles in a dielectric medium
and to balance the density mismatch among various nanoparticles. The modified particles
were dispersed in a suspending fluid and then were encapsulated to form microcapsules
of about 70 μm in diameter. Using gelatin and gum arabic as wall materials,
microcapsules were prepared via the phase separation of oppositely charged polymers. To
form the frontplane, a microcapsuled electrophoretic particles and polymer binder were
coated on a poly(ethylene terephthalate) film, where a thin indium tin oxide (ITO) layer
was deposited. We fabricated a 2.4 inch panel of 520 X 520 array of pixels with passive
matrix addressing.
LOW ENERGY CLUSTER BEAM DEPOSITION METHOD TO PRODUCE
FUNCTIONAL NANOSTRUCTURES AND HIGH INTEGRATION-DENSITY
DEVICES
Alain Perez, Patrice Mélinon, Veronique Dupuis, Bruno Masenelli, Laurent
Bardotti, Brigitte Prével, Florent Tournus, Juliette Tuaillon-Combes, Alexandre
Tamion, Estela Bernstein, Irène Wang, Nils Blanc, Dimitri Tainoff, Laboratoire de
Physique de la Matière Condensée et Nanostructures, University Claude Bernard
Lyon 1 and CNRS, 69622 Villeurbanne, France; [email protected]
43
Functional cluster-assembled nanostructures with original structures and properties are prepared
using the Low Energy Cluster Beam Deposition method (LECBD). This technique consists of
depositing supersonic clusters produced in the gas phase using a combined laser vaporization-inert
gas condensation source. Low energy clusters with typical sizes ranging from ~ 1 to a few nm are
not fragmented upon impact on the substrate leading to the formation of supported nanostructures
62
which retain the original structures and properties of the incident free clusters. Model
nanostructured systems of any kind of materials (metallic, covalent, oxides) well suited for
fundamental studies in nanoelectronics/nanomagnetism/nanophotonics and for applications to very
high integration-density devices (~ Tbits/in2) are prepared by this method. After a brief review of
techniques to produce, analyse, and deposit clusters in the LECBD regime, the specific aspects
of the nucleation and growth process which governs the cluster-assembled nanostructure
formation on the substrate will be presented. Characteristic examples of functionalized clusterassembled nanostructures prepared by LECBD will be also described: (i) magnetic
nanostructures from Co-based nanoclusters (i.e. Co-Pt, Co-Sm) exhibiting a high magnetic
anisotropy and blocking temperature well suited for applications to high density data storage
systems, (ii) highly photo luminescent nanostructures from rare earth doped sesquioxide
nanoclusters (i.e. Gd2O3:Eu3+) for applications to nanophotonics. Recent results on the
preparation of 2D-organized arrays of cluster-assembled nanostructures by depositing low
energy clusters on FIB-functionalized substrates in view to produce high integration-density
devices will be reported.
PREPARATION OF COMTAMINATION FREE SILVER
NANOPARTICLE SUSPENSIONS FOR MICRO-INTERCONNECTS BY
INK-JET PRINTING
Lien-chung Hsu, Rong-tarng Wu, Ming-Hsiu Tsai, Weng-Sing Hwang and
In-Gann Chen, Department of Materials Science and Engineering, National
Cheng-Kung University, Tainan, Taiwan, ROC; [email protected]
44
Highly concentrated and stable suspensions of silver nanoparticles have been synthesized
by chemical reduction from silver nitrate in a formaldehyde reductant using an organic
base, triethylamine, as the reaction promoter. In this reaction, a low molecular weight
organic compound, thiosalicylic acid (TSA), was used as the protecting agent. The
average size of the silver nanoparticles prepared from this method was less than 10 nm,
which allowed low-temperature sintering of the metal. The suspensions were further
stabilized by the addition of excessive triethylamine, which forms an amine salt with
TSA. A 50 wt%, stable suspension was prepared. The suspensions of silver nanoparticles
prepared by this method are free from any metal ion contamination, and are suitable for
use in semiconductor industries. It can be inkjet printed on a silicon substrate and sintered
at low temperature (below 300 oC) to form dot and line patterns.
A SURVEY OF NANOLITHOGRAPHIC TECHNIQUES USED TO
CREATE NANOSTRUCTURES
Nancy Van Suetendael and Susan Earles, Florida Institute of Technology,
Department of Electrical and Computer Engineering, 150 West University
Boulevard, Melbourne, FL 32901-6975, USA; Mary Helen McCay, Florida
Institute of Technology, National Center for Hydrogen Research, 150 West
University Boulevard, Melbourne, FL 32901-6975; [email protected];
[email protected]
45
63
Over the last few decades, the semiconductor industry has witnessed a major revolution
in manufacturing small electronic components, integrated circuits and chips. Now devices
are being produced at the nanometer scale. However, along with the ability to scale down
devices come challenges with designing and developing nanostructures that must operate
properly in an increasingly smaller environment. Understanding the surface properties of
materials at the atomic-scale level is one of the fundamental interests in advanced
materials processing. With the invention of the scanning tunneling microscope (STM)
and later, the field of scanning probe microscopy (SPM), the nature of materials' surfaces,
structure, electronic properties and reactivity could be thoroughly analyzed. Fabrication
and analytical methods discussed in this paper have been used over the past few decades
to create and characterize nanostructures formed on materials from porous Silicon (p-Si)
to thin polymer films, such as polymethylmethacrylate (PMMA). This paper briefly
discusses the evolution of the SPM, early nanolithographic techniques and Florida
Institute of Technology's current research efforts in this area. It then focuses on AFMbased electrostatic nanolithography and dip-pen nanolithography, both of which continue
to be valuable methods used to synthesize and pattern structures on a variety of materials.
The survey concludes with a section on potential device applications and future trends in
nanotechnology.
NOVEL APPLICATIONS OF COLLOIDAL LITHOGRAPHY
Jau-Ye Shiu, Chiung Wen Kuo and Peilin Chen, Research Center for Applied
Sciences, Academia Sinica, Taipei 115, Taiwan; [email protected]
46
In this presentation, we will describe a simple approach to fabricate robust two and threedimensional periodic porous nanostructures inside the microchannels using colloidal
lithography. To fabrication three-dimensional nanostructure in the microfluidic channels,
the colloidal crystals were first grown inside the microchannel using evaporation assisted
self-assembly process. Then the void spaces among the colloidal crystals were filled with
epoxy based negative tone photoresist. After subsequent development and nanoparticle
removal, the well-ordered three-dimensional nano-porous structures inside the
microchannel have been obtained. Depending on the size of the colloidal particles,
periodic porous nanostructures inside the microchannels with cavity size of 330 nm and
570 nm have been obtained. The dimension of interconnecting pores for these cavities
was around 30 nm. The behavior of single lambda phage DNA in these nanoporous
structures was studied using fluorescence microscope. It was found that the length of
DNA molecules oscillated in the nanoporous structures at an applied field of 5V/cm. The
measured length for lambda phage DNA molecules was larger in the 330 nm cavity than
those measured in the 570 nm cavity. To construct two-dimensional periodic array of
nanostructures inside the microfluidic channels, nanosphere lithography has been
employed to grow a single layer of well-ordered close-packed nanoparticle arrays inside
the microfluidic channels. The size of the polymeric colloidal nanoparticles could be
trimmed by oxygen plasma treatment. These colloidal nanoparticles were then used as the
etching mask in a deep etching process. As a result, well-ordered size controllable
nanopillar arrays could be fabricated inside the microfluidic channels. The gap distance
between the nanopillars could be tuned between 20 nm to 80 nm allowing the formation
64
of nanofluidic system where the behavior single lambda phage DNA molecule has been
investigated. It was found that the lambda phage DNA molecules could be fully stretched
in the nanofluidic system formed by nanopillars with 50 nm gap distance at a field of 50
V/cm.
Session F1 – Keynote Paper
ASSEMBLY OF ORIENTATIONALLY ORDERED
NANOCRYSTALLINE FILMS AND SUPERLATTICES
Lennart Bergström*1, Anwar Ahniyaz1,3, Niklas Hedin1, Yasuhiro
Sakamoto1, Peter Lipowski2, Rudolf C. Hoffmann2 Joachim Bill2 and Fritz
Aldinger2, 1Department of Physical, Inorganic and Structural Chemistry,
Arrhenius Laboratory, Stockholm University, Stockholm, Sweden; 2MaxPlanck-Institut für Metallforschung und Institut für Nichtmetallische
Anorganische Materialien der Universität Stuttgart, PML, Heisenbergstraße 3,
70569 Stuttgart, Germany; 3Institute for Surface Chemistry, YKI, Stockholm,
Sweden; [email protected]
47
Self-assembly has evolved into one of the prime “bottom-up” candidates for facile
manufacturing in nanotechnology. Self-assembly offers a high degree of versatility,
simplicity and flexibility in the production of bulk materials and coatings and allows the
introduction of specific functions with a high degree of spatial accuracy. Self-assembly
processes commonly scan a rich energy landscape with many metastable states that can
be kinetically arrested. This talk will give an overview of recent research on the synthesis
and assembly of inorganic particles with a focus on the formation of ordered arrays of
nanocrystal with well-defined size and shape, and deposition of nanostructured films on
substrates. Evaporation of dilute dispersions on various substrates yields colloidal arrays
and it will be demonstrated how the coverage and short-range order of the deposited
nanoparticles can be controlled. We will discuss how the characteristic dimensions of the
superlattice are controlled by the particle concentration as well as by introducing weak
magnetic field (PNAS, 104, 17570-17574, 2007). In addition, we will describe recent
work on controlled deposition of inorganic, crystalline films from solution. The thermally
activated mineralization of ZnO in a methanol solution is a complex process, including
the formation of a metastable amorphous intermediate phase followed by crystallization
and aggregation of ZnO nanoparticles. Comparisons with the formation of polycrystalline
zinc oxide films on substrates coated with organic self-assembled monolayers suggest
that it is the regulation of the concentration of reactive species through the formation, and
subsequent dissolution, of the intermediate amorphous phase in solution that controls the
formation of smooth and textured films.
Session F1 – Contributed Paper
STRUCTURAL DEVELOPMENT OF SOL-GEL DERIVED HYBRID
COLLOIDS FOR NANOPOROUS MATERIALS AND THIN FILM
MEMBRANES
Hessel L. Castricum, Johan E. ten Elshof, Dave H.A. Blank, MESA+
Institute for Nanotechnology, University of Twente, Enschede, the
48
65
Netherlands; Rob Kreiter, Jaap Vente, Energy Research Centre, Petten, the
Netherlands; [email protected]
We recenty developed a new type of sol-gel derived hybrid material with molecular
separation capacity for small molecules like H2O and H2. The material consists of a
polymerized 3D network of organofunctional silica precursors with pore sizes mainly in
the range 0.24-0.30 nm. It can be shaped into supported thin films of 20-100 nm
thickness by dipcoating. Thin film membranes made from this material have remained
operating stably at 150°C under hydrothermal conditions for more than 1.5 years already,
which is unprecendented for molecular-sieving membranes. They can be applied as
energy-efficient alternative to conventional technologies (e.g. distillation). The size and
shape of the sol particles need careful control in order to be able to derive defect-free thin
film membranes from them. In the present contribution we report a study on the structural
development of organofunctional silica sols. The sols were made from organofunctional
precursor solutions that are known to be suitable for the preparation of defect-free
molecular sieving membranes. They are based on mixtures of tetra-ethyl-orthosilicate
(TEOS), methyl-triethoxy-silane (MTES) and bis(triethoxysilyl)ethane (RO)3Si-C2H4Si(OR)3 (BTESE). We studied the effect of processing variables on size and shape of the
sol particles, i.e., precursors, water/Si and acid/Si molar ratios, and the sequence in which
the reactants were added to the mixture. The hydrolysis and condensation rates of the
individual precursors under acid-catalyzed reaction conditions were determined with 29Si
liquid NMR. More developed sols and mixtures of silanes were characterized by
Dynamic Light Scattering (DLS) to determine the hydrodynamic radius, and Small-angle
X-ray Scattering (SAXS) to determine particle size and fractal dimension. The structural
evolution of these sols, which typically have radii of gyration smaller than 2 nm, is
reported. We found that the hydrolysis rates of TEOS, MTES and BTESE differ
substantially. However, their rates of condensation are more or less similar after a short
induction period. It is therefore expected that mixtures of precursors are able to form
colloids in which different precursors are mixed on a molecular scale. Depending on the
composition of the mixtures, phase separation into more hydrophobic and more
hydrophilic regions can occur.
Session F1 – Invited Paper
KINETIC FEATURES OF METAL NANOPARTICLE FORMATION IN
POLYMER FILMS
G. Mills, A. S. Korchev, K. E. Foti, M. Sartin, Department of Chemistry and
Biochemistry, Auburn University, Auburn, AL 36849; [email protected]
B. L. Slaten, Department of Consumer Affairs, Auburn University, Auburn,
AL 36849
49
The photoreduction of Ag+ and Cu2+ ions present within thin, optically transparent films
consisting of sulfonated poly(ether ether ketone), SPEEK, and poly(vinyl alcohol), PVA,
was studied by means of UV-Vis spectroscopy in conjunction with EPR, XPS, IR and
TEM techniques. Titration of the films revealed that the solid polymer blends behave as
strong acids in aqueous solutions. Results from ion exchange experiments indicated that
the amount of Ag+ and Cu2+ ions incorporated into the films correspond to 55 and 30% of
66
sulfonic groups present in the SPEEK component, respectively. Optical and EPR data
showed that illumination of the films results in α-hydroxy (or benzophenyl ketyl, BPK)
radicals of SPEEK. Such radicals are believed to form when benzophenone (BP) groups
of SPEEK are excited by 350 nm photons into a (n, π*) triplet state, which then reacts via
hydrogen atom abstraction from PVA. The polymeric BPK radicals exhibited lifetimes
of 30 min and about 5 h in the presence and absence of air, respectively. Optical and
EPR results demonstrated that α-hydroxyl radicals of SPEEK are able to reduce Ag+ and
Cu2+ ions present in the films. The photoreduction of Cu2+ ions in the solid matrices
yielded cuprous ions; Ag+ ions were transformed into spherical silver crystallites with an
average diameter of 5 nm, which exhibited a surface plasmon signal centered at 395 nm.
Kinetic data revealed that the photoreduction of Ag+ took place via a monophotonic
process that was not affected by the presence of air. Such findings are not surprising
given that the coefficient for the diffusion of O2 inside PVA films is very low. Ag
particles were formed initially through a slow zero-order process, but the reaction rate
increased continuously at longer photolysis times. Such results suggest that Ag+ ions
quench the triplet state of the BP groups from SPEEK, inhibiting the formation of BPK
radicals. The inhibiting effect diminishes at longer times because increasing amounts of
the quencher are transformed into Ag particles as the photoreduction proceeds. The
activation energy for the photogeneration of metal particles amounted to 30 kJ/mol, a
value that is typical of free radical reactions. A second pathway for the formation of Ag
particles was noticed at T ≥ Tg for PVA (73 ºC). This process involved a thermal
transformation that occurred with an activation energy of 145 kJ/mol, and that was metalcatalyzed since no dark reduction of Ag+ was detected in films free of Ag particles.
Evidence will be presented that Ag crystallites become mobile within the polymer films
at long exposure times.
SCALABLE, SOLID STATE SYNTHESIS PROCESS FOR PRODUCING
NANOSTRUCTURED ELECTRODE MATERIALS
A. Singhal and G. Skandan, NEI Corporation, Somerset, NJ, 08873, USA; M.
Doeff, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; S.
Korutla, Lithium Technology Corporation, Plymouth Meeting, PA, USA;
[email protected]
50
Safe Li-ion batteries with high power density that can operate over a wide temperature
range, including temperatures as low as -30 oC, are required for hybrid electric vehicle
applications. Additionally, Li-ion batteries with improved “abuse tolerance” are desired
to reduce the use of expensive electronic control systems. Electrode materials with high
temperature and chemical stability are needed for HEV and other large format
applications. One approach to improve the safety and the performance of Li-ion batteries
is to replace the state-of-the-art cathode (e.g., LiCoO2, LiNi0.8Co0.15Al0.05O2) and carbonbased anode materials with alternative materials. The major challenge that needs to be
overcome before electrode materials with new chemistries can be commercialized in Liion batteries is their production cost. We have developed an economical single step, solid
state synthesis processes for producing nanostructured electrode (cathode and anode)
67
materials. It was observed that the rate performance of cathode materials, both at room
and low temperatures, is related to processing temperature, ratio of constitutients in the
raw material and the mass density of the powder. The rate performance of cathode
materials in half cells was a stronger function of the mass density than the electronic
conductivity, and it was comparable to that of a commercial material when tested in
conjunction with an improved low temperature LiBF4-based electrolyte (from Army
Research Laboratory) at 0oC. Full cells (capacity of 9 -12 mAh) made of nanostructured
cathode and anode with 1.0M LiPF6 electrolyte exhibited excellent cyclability.
A MOLECULAR DYNAMICS STUDY OF THE STRUCTURE OF
NANOPARTICLES OF PLATINUM AND ALLOYS OF PLATINUM
ADSORBED ONTO CARBON SUBSTRATES OF FUEL CELL
SUPPORTED CATALYSTS
Ram Subbaraman, Thomas Zawodzinski Jr., and J. Adin Mann, Jr.,
Department of Chemical Engineering, Case School of Engineering, Case
Western Reserve University, Cleveland OH 44106 USA; [email protected]
51
The kinetics of reactions at the anode and cathode structures of fuel cells depend on the
surface structure of supported nanocatalyst particles. The particle size and morphology of
the catalyst particles that decorate the carbon particle substrate are factors that determine
the efficacy of the redox reactions and therefore fuel cell operation. The motivation for
this research is the determination of structures that optimize fuel cell function. We
present the results of molecular dynamics (MD) simulations of the structure of
nanoparticles of platinum and several of its alloys, gold, cobalt, copper, iron, and
rhodium. The simulations include the effect of a carbon substrate on the morphology of
the nanoparticles including various bond orders (sums of spherical harmonics to form
various invariant functions) and the strain-vector field. The strain-vector field (the set of
displacement vectors between the atom locations at equilibrium and the reference state)
shows the distortion in the nanoparticle and on the surface atoms as a result of interaction
with the substrate. The effect of particle size on the strain-vector field observed
throughout the nanoparticle is discussed. Effects on particle morphology of alloying
elements and the nature of the support are discussed. Bond orders for atoms in the
clusters were calculated to further understand the presence of a secondary Mackay
transformation between the icosahedron and cuboctahedron morphologies. The atom
positions in a nanocrystal determined by MD along with the atomic number of each atom
is sufficient to construct a model of the image determined by high resolution transmission
electron microscopy (HRTEM). We compare simulated images and experimental images.
It is clear from both the simulations and experimental work that there is a sufficient shift
in the atom positions of adsorbed nanoparticles that the quantum chemistry is no longer
that of the classical platinum surfaces. We will comment on the catalyst design problem
implied by our results.
68
PLATINUM-BASED ALLOY AND INTERMETALLIC
NANOPARTICLES AS FUEL CELL CATALYSTS
Hong Yang, Department of Chemical Engineering, University of Rochester,
Rochester, NY 14627-0166, USA; [email protected]
52
Platinum-based nanostructures are excellent electrocatalysts in electro-oxidation of small
molecules and oxygen reduction reaction (ORR), which are important for the protonexchange membrane fuel cells (PEMFCs). Ordered intermetallic surfaces can further
improve the performance in these reactions over pure platinum. For practical application,
a big challenge is to control the shape, crystal phase, and composition of nanometer-sized
alloy catalysts in order to achieve high catalytic performance at low platinum content and
costs. In this presentation, I will present the strategies for controlling the shape of
platinum-based nanoparticles, the composition and crystal phase behavior of the alloy
and intermetallic nanostructures. Several heterogeneous and bimetallic platinum
nanostructures such as PtM (M=Pb, Pd, Ni, Fe, Co) will be covered. The formation
mechanism of nanostructures and the relationship between the structure and
electrocatalytic property of these nanomaterials will be discussed using direct methanol
or formic acid oxidation and oxygen reduction as the model reactions.
MULTIMETALLIC NANOPARTICLES AND NANOTECHNOLOGY IN
CATALYSIS
Chuan-Jian Zhong, Department of Chemistry, State University of New York
at Binghamton, Binghamton, NY 13902, USA; [email protected]
53
While multimetallic catalysts have long been exploited in catalysis, the understanding of
factors governing the synergistic activities of such catalysts is extremely challenging.
This presentation discusses recent findings of an investigation of the synthesis and
processing of bimetallic and trimetallic nanoparticles with controlled size, shape,
composition, and surface properties to understand their synergistic electrocatalytic
properties in fuel cell reactions. The synthesis strategy explores the manipulation of the
metal precursor and the capping agent concentration ratios in the reaction solution,
whereas the processing route explores thermally activated core-shell reactivities in a
highly-concentrated solution of the nanoparticles. The resulting nanoparticles with
controllable sizes (1-5 nm) and compositions (M1nM2100-n, and M1nM2mM3100-n-m) were
supported on a variety of powder supports including carbon, silica, titanium oxide, and
calcined by controlled thermal treatments. The nanoparticle catalysts were characterized
using an array of techniques including XRD, FTIR, TEM, EDX, XPS, AFM, and TGA,
and were examined for fuel cell electrocatalytic reactions, including methanol oxidation
reaction and oxygen reduction reaction. The activity and stability of the electrocatalysts
are discussed in terms of the synergistic properties of the bimetallic/trimetallic
nanoparticles, providing fundamental insights into correlations among the nanoscale
properties of the multimetallic catalysts, and roles of nanotechnology in the design and
preparation of advanced catalysts.
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NOVEL PREPARATION AND PHOTOCATALYTIC PROPERTY OF
WO3-V2O5/TiO2 NANOCOMPOSITES
Huaming Yang, Yuehua Deng and Chengli Huo, Department of Inorganic
Materials, School of Resources Processing and Bioengineering, Central South
University, Changsha 410083, China; [email protected]
54
WO3-V2O5/TiO2 nanocomposites have been successfully prepared via a novel method.
TiO2 precursor was successfully synthesized by a sol-gel method. The precursor,
ammonium tungstate and ammonium vanadiate were then mixed and milled for 10min to
produce a mixture. Subsequent thermal treatment of the mixture at 500°C for 4 h in air
results in the formation of WO3-V2O5/TiO2 nanocomposites with crystal size of 17 nm.
Energy dispersive spectroscopy (EDS) quantitative analysis indicated that
WO3:V2O5:TiO2 weight ratio of the synthesized nanocomposites is 7.89:12.41:79.70,
which agrees well with the scheduled weight ratio (8:12:80). Large numbers of microcrannies on particle surface is greatly beneficial to photocatalytic reaction. UV-vis
analysis indicates that this nanocomposite should be effective as a potential visible-lightdriven photocatalyst. The photocatalytic oxidation of methyl orange (MeO) in WO3V2O5/TiO2 suspensions under ultraviolet illumination was investigated. The results
indicate that a low pH value (pH=1.0) will improve the decolorization of the MeO
solution. The photodegradation degree decreases with increasing the pH value of
solution.
NANOPARTICLES AND NANOCAPSULES OBTAINED BY
MINIEMULSION POLYMERIZATION
Katharina Landfester1 ;1Institute of Organic Chemistry, University of Ulm,
Albert-Einstein-Allee 11, 89081 Ulm, Germany;
[email protected]
55
Functionalized nanoparticles and nanocapsules are of high interest in materials and
biomedical applications. The miniemulsion technique is a convenient and powerful tool
for the preparation of the specified polymeric particles or capsules with sizes ranging
from 150 to 300 nm. The basic step for the particle preparation is the formation of a
stable monomer-in-water miniemulsion. The particles are subsequently formed by
polymerization of the respective monomer. As an example, biodegradable poly(nbutylcyanoacrylate) nanoparticles and nanocapules were prepared by anionic
polymerization after the addition of a nucleophile to the miniemulsion. The choice of
nucleophile determines the functionalization of the particle surface. The particles can
excellently be used to pass the blood-brain barrier; various substances can be
encapsulated in the particles and can be delivered in the brain. Biocompatible
polyisoprene and polystyrene particles were synthesized through a radical polymerization
process. A surface functionalization of the polystyrene particles was obtained by
copolymerization with functional hydrophilic monomer such as acrylic acid or
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aminoethyl methacrylate. The degree of functionalization has a direct influence on the
cell uptake of these particles: the higher the functionalization is, the better the uptake in
various cell line is. A specific functionalization can be obtained by binding peptides,
proteins, or antibodies to the particles’ surface. Biodegradable poly(L-lactide) particles
have been obtained from the preformed polymer by emulsification/solvent evaporation
method, which is based on the precipitation of the polymer within the miniemulsion
droplets and formation of the solid particles. For later detection of the particles, a
hydrophobic fluorescent dye or magnetic particles was encapsulated into the polymer
matrix. The formation of stable hydrophilic monomer droplets in the continuous organic
phase offers the opportunity to perform the reaction not only within the droplets, but also
at their interface via interfacial polyaddition. The resulting particles have a “core-shell”
structure, consisting of a liquid cavity surrounded by a polymeric membrane. Therefore
such capsules give the possibility to protect the encapsulated material from the influence
of the environment. The nanocages with the hydrophilic core can be used as a transporter
for DNA or drugs. By variation of several reaction parameters such as monomer and
surfactant concentration, or the amount of the dispersed phase, the shell thickness can be
adjusted to be between 13 and 25 nm. Additionally, a cell marker as for magnetic
resonance imaging, fluorescent detection, and x-ray analysis can be incorporated.
DISPERSION POLYMERIZATION OF CROSS-LINKED POLY(2ETHYLHEXYL METHACRYLATE-CO-CHLOROMETHYLSTYRENE)
IN FLUORINATED SOLVENTS.
Yan Zhu, Rangarani Karnati, and Warren T. Ford, Department of
Chemistry, Oklahoma State University, Stillwater, OK 74078, USA;
[email protected]
56
With the aim of developing reactive polymer colloids in fluorinated solvents, amphiphilic
fluorinated block copolymers, poly(2-ethylhexyl methacrylate-b-(1H,1H-perfluorooctyl
acrylate)) and poly(2-ethylhexyl methacrylate-b-(1H,1H,2H,2H-perfluorooctyl acrylate))
were synthesized by atom transfer radical polymerization (ATRP) and characterized by
1
H NMR, IR and GPC analyses. Control of ATRP of the fluoropolymer block required a
fluoroalkyl substituted 2,2’-dipyridine ligand for the Cu(I) catalyst. The block
copolymers were investigated as stabilizers for the preparation of colloidal dispersions of
cross-linked poly(2-ethylhexyl methacrylate-stat-chloromethylstyrene) in the fluorinated
solvent HFE-7200 (an isomeric mixture of nonafluorobutyl ethyl ethers). The most
effective stabilizers had block lengths of (EHMA)30 and (FOA)45 or (THFOA)50. The
homopolymer of 1H,1H-dihydroperfluorooctyl acrylate also was an effective stabilizer
for this dispersion polymerization when the mixture was heated by microwave radiation.
Particle sizes decreased with increasing concentration of stabilizer. Surprisingly, the most
stable polymer colloids were obtained using block copolymers that were incompletely
soluble in HFE-7200 at 23 oC prior to polymerization.
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MONODISPERSE POLYSTYRENE PARTICLES PREPARED BY
POLYMERIZATION IN SILICA PARTICLE SUSPENSIONS WITHOUT
SURFACTANTS
Masashi Kunitake and Sintaro Kawano, New Frontier Science, Kumamoto
University, 2-29-1 Kurokami, Kumamoto, 860-8555, Japan;
[email protected]
57
The polymerization of styrene using a lipophilic initiator in an O/W emulsion stabilized
by unmodified mono-dispersed silica particles was conducted under static condition
without suspension. Styrene was suspended in aqueous solution with 1wt% or less of
silica particles (average diameter: 450nm). After the addition of AIBN as an initiator and
the elimination of oxygen, the polymerization was conducted for 24 h at 60 statically
without mixing the two phase solution consisting of an O/W emulsion and excess styrene.
Surprisingly, nearly-monodispersed PS particles with 200nm average diameter newlyformed by polymerization were observed with silica particles in the solution.
Furthermore, the emulsion consisted on silica and PS particles after polymerization was
very stable and no sedimentation was observed even after several weeks, although
obvious sedimentation was observed in silica dispersed solution after several days. In the
presentation, we will discuss the formation mechanism of mono-dispersed PS particles
and the stabilization mechanism of the silica/PS mixed particle solution.
SYNTHESIS AND CHARACTERIZATION OF TARGETED POLYMERIC
NANOPARTICLES FOR BIOMEDICAL APPLICATIONS
Yvon Durant University of New Hampshire, Materials Science Program,
G101 Parsons Hall, Durham NH 03824, USA; Ebo de Muinck, Angiogenesis
Research Center, Jose Conejo-Garcia, Microbiology and Immunology
department, Dartmouth Medical School, Borwell Research Building, 1
Medical Center Drive, Lebanon, NH 03756, USA; [email protected]
Nanoparticles can be engineered to have specific combinations of properties to allow
interaction with biological systems, while minimizing immune response and invasion.
Progressively nanotechnology allow more specific diagnostics, less invasive tests, more
effective therapy with fewer side effects and better comfort of patients. The following
examples will be elaborated upon with an emphasis on synthesis.
Diagnotics: Targeted magnetic nanoparticles sensors for Magnetic Resonance Imaging
of angiogenesis.
Polymeric nanoparticles containing a core of magnetite (Fe3O4) are functionalized with
polyethylene glycol and a NGR homing peptide. The PEG layer enhance circulation time
in the blood, while NGR allows targeting of the nanoparticles to CD13/APN cell surface
receptor, that are over expresses in areas of neo-vessels growth. This MRI contrast agent
has clinical utility for the diagnosis of cardiac diseases.
Therapeutics: Targeted Gene Delivery of DNA to the ovarian cancer microenvironment
We synthesized immunonanoparticles based on a combination of 3 phospholipids by self
and direct assembly . The immunoliposomes contain folded plasmid that code for
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interleukin 18 and green fluorescent protein (GFP), folded on spermamine. The
liposomes are functionalized with antiCD11c in order to target CD11c cell receptors that
are over expressed in ovarian cancer cells.
MODIFICATION OF POROUS PVC PARTICLES VIA
POLYMERIZATION OF ABSORBED MONOMERS IN STABILIZERFREE AQUEOUS DISPERSIONS
Shir Hammer, Michal Shach-Caplan, Yachin Cohen and Moshe Narkis,
Chemical Engineering Department, Technion–IIT, Haifa 32000, Israel;
[email protected]
59
The focal point of polymer science and technology tends to shift from wholly new
polymers towards polymer blends. A unique method for the preparation of polymer
blends is in-situ polymerization, which is the polymerization of one monomer in the
presence of another polymer. In-situ polymerization in relatively large porous particles
(>100 µm) is infrequent in the literature. Porous PVC particles can absorb liquid
monomers, such as styrene, acrylates, or mixtures thereof, through filling the pores,
dissolution in the PVC particle, or both. The monomer absorption level should be below
the saturation absorption to secure that all the monomer absorbed is imbedded within the
particle. Thus, particles can be dispersed in water while the absorbed monomer remains
within them. The presence of an initiator dissolved in the absorbed monomer causes
polymerization within the porous particle dispersed in the aqueous dispersion at a
selected temperature. Under such polymerization conditions particle sticking is prevented
and dispersion stabilizers are not required. Recently, a novel modification process was
developed at the Technion, where an in-situ dispersion stabilizer-free
polymerization/crosslinking of monomers within porous, suspension-type seed polyvinyl
chloride (PVC) particles takes place. The polymerization/crosslinking of a given
monomer within a porous particle of uncrosslinked polymer has led to the formation of
semi-interpenetrating polymer network (SIPN) and fine polymeric particles distributed in
the hot melt processed PVC matrix. PVC is one of the most widely used polymers in the
plastics industry. Modified properties such as processability, flexibility and impact
strength have been achieved, thus production of new rigid PVC materials, modified by
the novel in-situ method of polymerization of a monomer within suspension type porous
PVC particles. The in-situ polymerization method, morphology of the modified PVC
particles, their hot melt processability along with characteristics of thermally stable
injection molded materials are presented.
FACILE SYNTHESIS OF LUMINESCENT MAGNETIC NANO-AND
MICROSPHERES: EMBEDDING OF QUANTUM DOTS AND
MAGNETITE NANOPARTICLES IN A POLYMER MATRIX
Jin Seon Park, Piercen Oliver and Dmitri Vezenov, Chemistry Department,
Lehigh University, Bethlehem, PA 18015, USA; [email protected]
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We developed a new fabrication route to micron and sub-micron sized polystyrene (PS)
and poly (methyl methacrylate) (PMMA) spheres that contain quantum dots (core/shell
CdSe/CdS or CdSe/ZnSe/ZnS) and magnetite (Fe3O4) nanoparticles. The composite
spheres were prepared from the bulk polymers with reaction times on the order of a few
minutes. We were able to control the diameter of the spheres from 100 nm to 20 µm by
changing reaction conditions. These polymer particles with fluorescent and magnetic
inclusions were characterized in terms of their size distributions, surface morphology,
fluorescence, and magnetic properties using scanning electron microscopy, dynamic light
scattering, fluorescence microscopy, and Stokes drag analysis. Termination of the surface
of these particles with carboxylic acid groups was achieved by using poly(methyl
methacrylate co-methacrylic acid) (PMMA-MAA) or poly(styrene-b-acrylic acid) (PSSb-PAA) as a second component in the polymer matrix. A number of applications of these
particles become possible by exploiting reactivity of the surface carboxyl groups. The use
of these probes in force spectroscopy experiments will be discussed.
Session G1 – Keynote Paper
THE ROLE OF SUPRAMOLECULAR STRUCTURE IN
NANOPARTICLE-CELL INTERACTIONS
Francesco Stellacci, Department of Materials Science and Engineering,
Massachusetts Institute of Technology, 77 Massachusetts Ave. 13-4053
Cambridge, MA, 02139, USA; [email protected]
61
It is know that specific molecules can spontaneously arrange on various surfaces forming
two-dimensional poly-crystalline mono-molecular layers called self-assembled
monolayers (SAMs). These organic coatings are used to impart targeted optical,
electronic and biological properties to surfaces. Very often SAMs composed of more than
one type of molecule (mixed-SAMs) are used to simultaneously impart multiple
properties. Scanning tunneling microscopy (STM) studies have shown that, in mixed
SAMs, molecules phase-separate in domains of random shape and size. We will show
that when mixed SAMs are formed on surfaces with a radius of curvature smaller than 20
nm they spontaneously phase-separate in highly ordered phases of unprecedented size.
The reason for this supramolecular phenomenon is purely topological and can be
rationalized through the “hairy ball theorem”. In the specific case of mixed SAMs formed
on the surface of gold nanoparticles, the molecular ligands separate into 5 Å wide phases
of alternating composition that encircle or spiral around the particle metallic core. This
new family of nano-structured nano-materials shows new properties solely due to this
novel and unique morphology. For example, we will show that the cell uptake of these
particles strongly depends on the particle’s composition and the ligand shell morphology.
Session G1 – Contributed Paper
QUANTUM DOTS (QDS) ENCODED MICROBEADS WITH
MAGNETISM AND CARBOXYL-ENDS
Kang Sun ,Hongjing Dou, Wanwan Li, Pengfei Zhang, and Bin Xu, School
of Materials Science and Engineering, Shanghai Jiao Tong University, 800
Dongchuan Road, Shanghai 200240, China; [email protected]
62
Recently, the advances in modern bio-analytical science, biological imaging and clinical
74
diagnosis required to develop a technology which could process a large number of
biological data and separate target biological molecules with high efficiency. The
developments in nanotechnology make it possible to synthesize various functional
nanoparticles with fluorescent, magnetic or electronic properties. Incorporation of
functional nanoparticles into polymer microbeads can combine the advantages of both
nanoparticles and microbeads. For example, Quantum dots (QDs) encoded multiplexed
optical microspheres, which could theoretically achieve one million of labels with only 6color and 10-intensity of QDs were practically feasible, are one of the most promising
techniques for massively parallel and high-throughput analysis of biological molecules,
and microbeads doped with magnetic nanoparticles (MNPs) are of great potential in cell
sorting and assay separation. However, only limited research focused on developing
multi-functional microbeads that allow simultaneous target encoding, enrichment,
separations and bio-affinity. Herein, we report a strategy of fabricating carboxyl capped
multi-functional microbeads (MFMs) with luminescent and magnetic functionalities. Our
strategy to fabricate MFMs includes two steps: synthesis of porous PS microbeads with
carboxyl-ends by combination of dispersion polymerization and seeded polymerization,
and the facile embedding process of QDs and MNPs into microbeads. As is well known,
MNPs possess excellent superparamagnetic properties, and QDs have unique optical and
electronic properties such as size-tunable light emission, improved signal brightness,
resistance against photo bleaching, and simultaneous excitation of multiple fluorescence
colors. Moreover, carboxyls on the surface of microbeads can be coupled with biological
molecules or agents, and enhance the dispersibility and stability of microbeads in
aqueous solution. Therefore the resultant multi-functional microbeads are anticipated to
be the novel microcarriers which possess surface functional groups, well waterdispersibility, fluorescence, as well as magnetism. Our research results display that the
multi-functional microbeads are promising in many medical fields.
MULTIFUNCTIONAL NANOSTRUCTURED COMPOSITE COLLOIDS
PREPARED USING A MINIEMULSION APPROACH
Chantal Paquet, Kanchana Somaskandan, Arnold Kell, Benoit Simard,
Steacie Institute for the Molecular Sciences, National Research Council, 100
Sussex Drive, Ottawa, Ontario K1A 0R6, Canada; [email protected]
63
Colloidal nanostructures with magnetic and luminescent functionalities are potential
candidates for diagnostic tools, such as in magnetic cell capture and detection based on
an optical readout. This presentation examines miniemulsion-based methods used to
generate colloidal clusters of luminescent quantum dots and magnetic iron-based
nanoparticles. The colloidal clusters are encapsulated in poly(carboxylic acid), allowing
surface modification with small molecule probes, DNA or antibodies. We show that the
architecture of the colloid containing the nanoparticles plays an important role in the
luminescence properties of the quantum dots. The colloid architectures that optimize
quantum dot luminescence as well as magnetic response, thereby leading to enhanced
cell detection capabilities, are presented.
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OLIGONUCLEOTIDE-COATED METALLIC NANOPARTICLES AS A
FLEXIBLE PLATFORM FOR MOLECULAR IMAGING AGENTS
Nitin Nitin1, D. Javier2 and R. Richards-Kortum2, 1Department of
Biomaterials, Southwest Research, San Antonio, TX, USA;
[email protected] ; 2Department of Bioengineering, Rice University,
Houston, TX
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Targeted metallic nanoparticles have shown promise as contrast agents for molecular
imaging. To obtain molecular specificity, the nanoparticle surface must be appropriately
functionalized with probe molecules that will bind to biomarkers of interest. The aim of
this study was to develop and characterize a flexible approach to generate molecular
imaging agents based on gold nanoparticles conjugated to a diverse range of probe
molecules. We present two complementary oligonucleotide-based approaches to develop
gold nanoparticle contrast agents which can be functionalized with a variety of
biomolecules ranging from small molecules, to peptides, to antibodies. The size,
biocompatibility, and protein concentration per nanoparticle are characterized for the two
oligonucleotide based approaches; the results are compared to contrast agents prepared
using adsorption of proteins on gold nanoparticles by electrostatic interaction. Contrast
agents prepared from oligonucleotide-functionalized nanoparticles are significantly
smaller in size and more stable than contrast agents prepared by adsorption of proteins on
gold nanoparticles. We demonstrate the flexibility of the oligonucleotide-based approach
by preparing contrast agents conjugated to folate, EGF peptide, and anti-EGFR
antibodies. Reflectance images of cancer cell lines labeled with functionalized contrast
agents show significantly increased image contrast which is specific for the target
biomarker. To demonstrate the modularity of this new bioconjugation approach, we use it
to conjugate both fluorophore and anti-EGFR antibodies to metal nanoparticles, yielding
a contrast agent which can be probed with multiple imaging modalities. This novel
bioconjugation approach can be used to prepare contrast agents targeted with
biomolecules that span a diverse range of sizes; at the same time, the bioconjugation
method can be adapted to develop multimodal contrast agents for molecular imaging
without changing the coating design or material.
Session G1 – Invited Paper
QUANTUM DOT-BIOCONJUGATES: CHARACTERIZATION AND USE
FOR SENSING AND LIVE CELL IMAGING
Kimihiro Susumu, Igor L. Medintz, and Hedi Mattoussi, US Naval Research
Laboratory, Division of Optical Sciences and Center for Biomolecular
Science and Engineering, Washington, DC 20375;
[email protected]
65
Colloidal semiconductor nanocrystals (Quantum dots, QDs) have several unique optical
and spectroscopic properties that make them ideally suitable for use as fluorescent tags to
develop a variety of biological assays, ranging from molecular sensing to in vivo cellular
imaging. However, the best quality nanocrystals (made using high temperature solution
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reaction routes) are hydrophobic and, therefore, not compatible with biological systems.
We have developed approaches based on cap exchange of the native capping shell with
modular compact ligands to promote their dispersion in a wide range of buffers. These
ligands are based on the bi-dentate dihydrolipoic acid (DHLA) motif, and each is made of
a DHLA anchoring head, poly(ethylene glycol) segment with tunable size and a terminal
functional group; the latter promotes biocompatibility of the nanocrystals. We have also
developed conjugation strategies based on non-covalent self-assembly to couple CdSeZnS core-shell QDs to a variety of biomolecules. We start with brief characterization of
the ligands along with the hydrodynamic dimensions of a series of CdSe-ZnS
nanoparticles functionalized with various hydrophilic shells. We will complement that
with a molecular characterization of the kinetics driving self-assembly of QDprotein/peptide conjugates (prepared via metal-affinity driven interactions). We then
provide a few specific examples where these hybrid bioconjugates were employed in
sensor design, or to probe the uptake of QD assemblies by live cells.
SYNTHESIS AND BIOMEDICAL APPLICATIONS OF UNIFORM-SIZED
NANOPARTICLES
Taeghwan Hyeon* Jaeyun Kim, Hyon Bin Na, Kwangjin An, Taekyung Yu,
Soon Gu Kwon, National Creative Research Initiative Center for Oxide
Nanocrystalline Materials and School of Chemical and Biological
Engineering, Seoul National University, Seoul 151-744, South Korea;
[email protected]
#66
We developed new generalized synthetic procedures to produce monodisperse
nanocrystals of many transition metals and their oxides without a size selection process.
The synthesized nanocrystals include metals (Fe, Cr, Cu, Ni, and Pd), and metal oxides
(γ-Fe2O3, Fe3O4, CoFe2O4, MnFe2O4, NiO, and MnO) and MnS). We report the ultralarge-scale (10s of grams) synthesis of monodisperse nanocrystals of magnetite and MnO
from the thermolysis of metal-oleate complexes. We used some of these uniform-sized
nanoparticles for various biomedical applications. We developed a new T1 MRI contrast
agent using biocompatible manganese oxide (MnO) nanoparticles. When the MnO
nanoparticles were injected bolus to a mouse through a tail vein line, the detailed
anatomic structures of the brain, kidney, and spinal cord, were depicted in contrast
enhanced T1-weighted MRI. Furthermore, functionalized MnO nanoparticles prepared by
conjugation with a tumor specific antibody were used for imaging selectively the breast
cancer cells in the metastatic brain tumor model. We reported on the fabrication of
monodisperse nanoparticles embedded in uniform pore-sized mesoporous silica spheres
and PLGA polymers. We fabricated magnetic gold nanoshells consisting of gold
nanoshells (for NIR photothermal therapy) that are embedded with Fe3O4 nanoparticles
(for MRI contrasting agent), and conjugated them with cancer targeting agent (for
targeting). Cancer cells targeted with magnetic gold nanoshells were detectable by a
clinical MRI system and rapidly destroyed by exposing them to femtosecond laser pulses
of NIR wavelength at a low power. We synthesized Ni/NiO core/shell nanoparticles and
applied them to the selective binding and subsequent magnetic separation of histidinetagged proteins. We synthesized hollow magnetite nanocapsules and used them for both
the MRI contrast agent and magnetic guided drug delivery vehicle.
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DESIGN OF GOLD NAONPARTICLES FOR ULTRASENSITIVE
BIODIAGNOSTICS USING SERS
Radha Narayanan1, Gufeng Wang,2 Robert J. Lipert,2 Marc D. Porter;
1
Center for Nanobiotechnology, Department of Chemistry, Chemical
Engineering, and Bioengineering, University of Utah, 315 South 1400 East,
Salt Lake City, UT 84112 USA; 2Institute of Combinatorial Discovery and
Ames Laboratory-USDOE, Iowa State University, Ames, IA 50011 USA;
[email protected]
67
The drive for early disease detection, the growing threat of bioterrorism, and a vast range
of challenges more generally in biotechnology have markedly amplified the demand for
ultrasensitive, high-speed diagnostic tests. This presentation describes efforts to develop
platforms and readout methodologies that potentially address demands in this arena
through a coupling of nanometric labeling with surface enhanced Raman scattering
(SERS). It specifically details the results from studies to elucidate the underlying factors
that contribute to the higher SERS enhancements and lower detection limits observed for
spherical and cubic CTAB stabilized gold nanoparticles (sp-CTAB-Au NPs and cuCTAB-Au NPs) compared to spherical citrate stabilized gold nanoparticles (sp-cit-Au
NPs). We found that the use of sp-CTAB-Au NPs and cu-CTAB-Au NPs as extrinsic
Raman labels (ERLs) lowers the limits of detection (LOD) by ~40x and ~340x for
sandwich-based assays for human IgG protein in comparison to that for sp-cit-Au NPs.
The role of the transition of capping agent from citrate to CTAB is investigated via a
series of zeta potential measurements, solution extinction spectra, and TEM images
during different stages of ERL preparation. The manner by which the ERLs bind to the
capture substrate was investigated by surface extinction spectral studies as well as by
SEM imaging. Moreover, the importance of possible differences in the surface area of
the nanoparticles with respect to the amount of Raman reporter molecules that coat the
nanoparticle surface is examined by fluorescence binding studies. Possible origins for
the differences in LODs, including electromagnetic effects (e.g., hot spots and lightning
rod effects), will be discussed. These findings will also be examined in light of issues
related to nonspecific adsorption. New approaches to expand the number of potential
labels through the use of mixed monolayer coatings as intrinsically strong Raman labels
will briefly be reported.
IN SITU DETECTION OF CELLULAR EXOCYTOSIS WITH A SINGLEWALLED CARBON-NANOTUBE FIELD-EFFECT TRANSISTOR
Yit-Tsong Chen, Department of Chemistry, National Taiwan University, and
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106,
Taiwan; [email protected]
Single-walled carbon nanotubes (SWCNT) based field-effect transistor (FET) has been
used to monitor the synaptic transmissions among primary cultured embryonic cortical
neurons. Chromogranin A (CgA), one of the molecules released from secretory vesicles
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when the vesicles are fused with plasma membrane, is a diagnostic marker for
neuroendocrine tumors and neurodegenerative diseases like Parkinson’s and Alzheimer’s
diseases. Therefore, the detection of CgA is an excellent indicator of synaptic activity
when synaptic vesicle at the presynaptic terminal is triggered to undergo exocytosis. We
have demonstrated that the CgA released from the synaptic terminal of living neurons,
stimulated by glutamate, can be detected in situ by the CgA-antibody modified SWCNTFET (termed CgA-Ab/SWCNT-FET with high selectivity. The low amount of CgA
released from cultured neurons could not be monitored by immunoassay kits. Neither
could it be detected with a Western blot in bath buffer. This label-free and highly
sensitive SWCNT-FET biosensor, capable of measuring the immediate-vicinity release of
CgA from neurons, is promising in medical examination and can further be applied to
study the activity of individual neurons. The detection limit of the CgA peptides by CgAAb/SWCNT-FET can be as low as 1 nM. To further exploit the sensory applicability of
SWCNT-FET for biological research, we have also applied CgA-Ab/SWCNT-FET to
detect the release of CgA from cultured single bovine chromaffin cells. The histamineevoked exocytotic release of CgA from a single bovine adrenal chromaffin cell was
detected in situ by CgA-Ab/SWCNT-FET. In the experiment, we have demonstrated that
CgA-Ab/SWCNT-FET can discriminate the amount of CgA release depending on the
strength of histamine stimulation.
ELECTRIC DETECTION OF BIOMOLECULES BY NANOPARTICLENANODEVICE
Wan Soo Yun, Korea Research Institute of Standards and Science, Yuseonggu, Daejeon 305-600, Korea; [email protected]
69
Nanoparticles can be adoted in nanodevices for the electric detection of biomolecules.
When two electrodes are separated from each other by a distance which is camparable to
the size of a conducting nanopaticle, immobilization of the nanoparticles in between the
electrodes, or in a nanogap, leads to a jump in the electric conductance of the nanodevice.
If this immobilization event is driven by a biomolecular recognition process, the device
can work as a biosensor. Here, we report on the electric detection of biomolecules like
DNAs and proteins by the combination of biofuctionalized nanoparticles and an
interdegitated nanogap device whose surface also was biofuctionalized. Oligonucleotides
and cancer-specific antigens in pM level were successfully detected by this method and
their concentration were to be estimated from the integaration of the devices. We believe
that this nanoparticle-nanodevice should be a promising alternative for the nanotechbased biomolecular sensing.
Session H1 – Keynote Paper
NANOMEDICINE: NANOPARTICLES OF BIODEGRADABLE
POLYMERS FOR CANCER TREATMENT
Si-Shen Feng Department of Chemical & Biomolecular Engineering and
Division of Bioengineering, National University of Singapore, Singapore;
[email protected]
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Cancer is a leading cause of death and has become the #1 killer in many eastern countries
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such as Singapore. There has been no substantial progress in fighting cancer. The cancer
death rate in US was 1.939‰ of the total population in 1950 and still 1.940‰ in 2001,
1.934‰ in 2002 and 1.901‰ in 2003 and 158.8‰ in 2004. Nanomedicine/Cancer
Nanotechnology/Chemotherapeutic Engineering will radically change the way we
diagnose, treat and prevent cancer and fatal diseases. This presentation demonstrates
through a full spectrum of proof-of-concept research how nanoparticle technology could
provide an ideal solution to promote new-concept chemotherapy, which may include
sustained, controlled and targeted chemotherapy; personalized chemotherapy;
chemotherapy across various physiological drug barriers; and eventually, chemotherapy
at home. Vitamin E TPGS coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles and
poly(lactic acid) (PLA)-vitamin E TPGS copolymer nanoparticles are used as examples
to formulate paclitaxel as model drug. Drug-loaded nanoparticles are characterized by
various state-of-the-art techniques, including laser light scattering for size and size
distribution, scanning electron spectroscopy (SEM) and atomic force microscopy (AFM)
for surface morphology, X-ray photoelectron spectroscopy (XPS) for surface chemistry,
and zeta-potential for surface charge. Drug encapsulation efficiency and in vitro drug
release profile is measured by high performance liquid chromatography (HPLC). The
cellular uptake of fluorescent nanoparticles is quantitatively investigated by confocal
laser scanning microscopy (CLSM) with Caco-2 cancer cells. In vitro HT-29 cancer cell
viability experiment shows that paclitaxel formulated in the nanoparticles could be 46
times more effective than Taxol® after 24 hours of treatment. In vivo pharmacokinetics
shows that the drug formulated in PLA-TPGS nanoparticles could achieve 3.9 times
higher therapeutic effects judged by area-under-the curve (AUC) and 23.0 times longer
half-life than Taxol®. One shot can realize sustainable chemotherapy of 336 hours
compared with 22 hours for Taxol® at a single 10 mg/kg dose. Xenograft tumor model
confirmed the advantages of the nanoparticle formulation versus Taxol®. Scientifically,
we proved that nanoparticles of small enough size and appropriate surface coating can
escape from elimination by the reticuloendothelial system (RES) and thus shows the
feasibility of nanotechnology for biomedical applications.
Session H1 – Contributed Paper
PARTICLE-STABILIZED EMULSIONS: SKIN PENETRATION STUDIES
COMPARED TO CLASSICAL EMULSIONS.
Justyna Frelichowska2, M. A. Bolzinger1,2, J. Pelletier J1,2, Y. Chevalier2;
Université Lyon 1, ISPB Faculté de pharmacie; (1)Laboratoire de
Dermopharmacie et Cosmétologie, F-69008, Lyon, France; (2)CNRS,
UMR5007, Laboratoire d'Automatique et de Génie des Procédés, F-69622,
Villeurbanne, France; [email protected]
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Pickering emulsions are stabilized solely by solid particles; therefore they are surfactantfree emulsions. This is especially attractive for cosmetic applications but it needs to be
evaluated with that respect. We describe for the first time skin absorption studies of
Pickering emulsions and we compare the behavior of Pickering emulsion to the
emulsifier–stabilized one. The fate of silica nanoparticles in the skin was also
investigated. To prepare Pickering emulsions, no emulsifier is required. This is an
interesting approach in cosmetic formulation, and also for topical pharmaceutical
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application. The solid particles that coat the emulsion droplets form a shell-like structure.
Due to the strong adsorption of particles at the oil/water interface, Pickering emulsions
exhibit an extraordin`ary stability. Thus, the active substance release and skin absorption
behavior may be different in comparison to emulsifier-stabilized emulsions. The skin
absorption of Pickering emulsions of oil-in-water and water-in-oil type was investigated.
For each Pickering emulsion, the corresponding emulsifier-stabilized emulsions were also
studied. The only difference in the composition of Pickering and classical emulsion was
the choice of stabilizing agent: the partially hydrophobic silica for Pickering emulsions
and an appropriate emulsifier for classical emulsions. According to our knowledge, no
such comparative studies were performed before. For oil-in-water emulsions retinol was
chose as a model lipophilic ingredient. For Pickering emulsion, most of the retinol was
found in the skin horny layer. For the emulsion stabilized by emulsifier, retinol
penetrated deeper and reached the dermis. The results suggest that Pickering emulsions
are well adapted for delivery of very lipophilic ingredients to the skin surface. For waterin-oil emulsions caffeine was chosen as a model hydrophilic active ingredient. The
kinetics of caffeine absorption was twice higher than for the emulsifier-stabilized
emulsion. The distribution profile of caffeine in the skin layers was also different. More
caffeine was found in the dermis for Pickering emulsion than for classical emulsion. The
results show that Pickering emulsion is best suited to hydrophilic active ingredient
delivery into deep layers of the skin. The faster skin absorption did not result from a
faster active ingredient release from Pickering emulsion because the in vitro release was
slower for Pickering emulsion. The rigid shell that surrounded the droplets slowed down
the release rate. The silica particles that stabilize Pickering emulsion were silica
aggregates of approximate size 160 nm. The fate of the nanometric silica particles is a
concern with respect to possible harmfulness of nanoparticles. The silica particles were
found only in the most external stratum corneum layers, corresponding to 5 µm of skin
depth. Thus, the silica particles penetrate into external layers of the skin, which are
desquamated. Pickering emulsions stabilized by silica particles as relatively safe
formulation for topical application.
Session H1 – Invited Paper
DEXTRAN-COATED CERIUM OXIDE NANOPARTICLES WITH pHDEPENDENT ANTIOXIDANT PROPERTIES
J. Manuel Perez, Nanoscience Technology Center, Chemistry Department,
University of Central Florida, Orlando, Fl 32826, USA;
[email protected]
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Cerium oxide nanoparticles (nanoceria) are potent free radical scavengers with
neuroprotective, radioprotective and anti-inflammatory properties. We will present the
facile synthesis of monodisperse, water-soluble and highly crystalline dextran-coated
nanoceria with unique pH-dependent antioxidant activity. Our data show that dextran
nanoceria loses its antioxidant properties at low (acidic) pH and it cannot be regenerated
upon increasing the pH. The observed non-reversible poisoning of dextran nanoceria at
low pH could have important implications in cancer therapy, as most tumors have acidic
microenvironments due to high rate of glycolysis and lactic acid production. Since
generation of oxygen radicals (oxidative stress) occurs during radiotherapy, leading to
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healthy tissue damage, biocompatible dextran nanoceria could facilitate the protection of
healthy tissue throughout these treatment regimes. Upon treatment with dextran
nanoceria, cancer cells are not be protected against oxidative stress, due to their acidic
microenvironment. In contrast, normal cells at neutral pH will be protected. We will
present data showing the preferential cytoprotection of nanoceria-treated normal cells
versus cancer cells in culture during oxidative stress. A possible mechanism for this
behavior will be discussed.
COLLOIDAL DELIVERY SYSTEMS FOR MICRONUTRIENTS AND
NUTRACEUTICALS
Krassimir Velikov, Unilever Food and Health Research Institute, Olivier van
Noortlaan 120, 3133AT, Vlaardingen, The Netherlands;
[email protected]
73
The formulation of micronutrients and nutraceuticals in the design of functional foods
brings enormous technological challenges. The incorporation of micronutrients and/or
micronutrients can compromise the product functionality. Issues are often encountered
related unwanted changes in the product physic-chemical stability, appearance, texture,
flavor, taste and bioavailability due to inherited instability or interactions with other
ingredients. This paper intends to present the general strategies in using colloidal
nanodispersions as delivery systems for micronutrients and nutraceuticals. Some
illustrative examples will be given on how colloidal delivery systems can address these
issues in the design of new functional foods.
ENZYME RESPONSIVE HYDROGEL PARTICLES FOR CONTROLLED
RELEASE
Paul D. Thornton, Tom O. McDonald, Robert J. Mart, Simon J. Webb and
Rein V. Ulijn, Manchester Interdisciplinary Biocentre (MIB) and School of
Materials, University of Manchester, 131 Princess Street, Manchester, M1
7DN, UK; [email protected]
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This talk will focus on design, characterisation and application of hydrogel particles with
enzyme-responsiveness built-in. These particles, based on amino-functionalised
poly(ethylene glycol acrylamide) (PEGA), are functionalised with peptide actuators that
cause charge-induced swelling and payload release when exposed to a (disease specific)
target enzyme. We will discuss the design rules of the peptide based actuators that control
the responsiveness of these materials. Specifically, we will report on design of peptide
actuators to match the specificity of the target enzyme, the charge properties and size of
the to-be released protein payload and the pH and ionic strength of the solution.
Fluorescently labelled albumin and avidin, proteins of similar size but opposite charge,
were released at a rate that was governed by the peptide actuator linked to the polymer
carrier, offering a highly controlled release mechanism. Release profiles were analysed
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using a combination of fluorescence spectroscopy of the solution and two-photon
fluorescence microscopy to analyse enzymatically triggered molecular events within
hydrogel particles during the initial stages of release.
NANOPARTICLES IN DIAGNOSTIC AND THERAPEUTIC DOMAIN
Hanna Mouaziz1, Damia Mawad1, Alexandra Penciu1, Yves Chevalier1,
Hatem Fessi1, Henri Méhier2; 1LAGEP, Laboratoire d’Automatique et de
Génie des Procédés, UMR CNRS n°5007, Université Claude Bernard Lyon 1,
France ; 2CERMA, Bâtiment Actipro, Parc d’affaires international,
Archamps, France; [email protected]
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Nanoparticles based on biocompatible and/or biodegradable polymers found widespread
application in drug delivery. Encapsulation of drugs within the particles allows its slow
release following its injection in the targeted organ. This study investigates the
development of nanoparticles with radiopaque properties for the localized delivery of
chemotherapeutic agents such as Paclitaxel. While adding radiopacity to the nanoparticles
will facilitate the accurate deposition of the delivery system in the targeted tumor and its
tracking over time, encapsulation of Paclitaxel in a polymeric system will prevent the drug
from spreading systemically and hence minimizes its toxicity. Two strategies have been
developed to impart radiopacity in the nanoparticles. On one hand, nanoparticles were
obtained from radiopaque polymers by “nanoprecipitation” technique. On the other hand,
nanocapsules containing an iodinated oil core surrounded by a classical biodegradable
polymer shell were formulated by “emulsion-diffusion” technique. The anticancer agent
could be encapsulated inside both types of nanoparticles. In the first strategy, polymers such
as cellulose and cellulose acetate were modified with mono and tri-iodobenzoic chloride
by means of ester bonds. Radio-opaque polymers having high iodine content (around 50
%) have been prepared and characterized by NMR and elemental analysis. Stable
suspensions of nanoparticles were prepared by the “nanoprecipitation” technique. Sizes
of particles varied around 100 nm as characterized by light scattering and electron
microscopy. Radio-opacity of pure polymer materials and suspensions of nanocapsules
was assessed by X-ray. Encapsulation and in vitro release of Paclitaxel were investigated.
In the second strategy, nanocapsules have been obtained by the “emulsion-diffusion”
technique using the usual contrast agent Lipiodol as the iodinated oil and the
biodegradable polycaprolactone as a polymer shell. The formulation was optimized with
respect to the oil-to-polymer ratio and emulsifier content. Stable nanocapsules of 450 nm
were obtained as characterized by light scattering and electron microscopy. In particular,
transmission electron microscopy allowed distinguishing the nanocapsule morphology as
a sphere with an oil core and a polymer shell. Radio-opacity and encapsulation of
Paclitaxel were also investigated as for the suspensions of nanoparticles. These two
strategies allowed the formulation of nanoparticles suspensions containing iodine. These
suspensions had sufficient X-Ray visibility. In addition, encapsulation of Paclitaxel was
successfully achieved. In conclusion, radiopaque nanoparticles combining diagnostic and
therapeutic applications were developed.
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STIMULI-RESPONSIVE MESOPOROUS NANOPARTICLES FOR
INTRACELLULAR CONTROLLED RELEASE AND BIOENERGY
APPLICATIONS
Victor S.-Y. Lin, Department of Chemistry, US DOE Ames Laboratory,
Iowa State University, Ames, IA 50011-3111, USA; [email protected]
76
We have synthesized a series of multi-functionalized, MCM-41 type mesoporous silica
nanosphere (MSN) materials. These MSN materials were designed as a stimuliresponsive controlled release delivery system (Figure 1). Several pharmaceutical drugs,
genes, proteins, and imaging agents were encapsulated inside the mesopores of MSN by
capping the openings of the mesopores with various chemically removable caps to block
the molecules of interest from leaching out. We studied the stimuli-responsive release
profiles of these MSN delivery systems by using various non-cytotoxic chemicals as
release triggers. Furthermore, the gene transfection efficacy, uptake mechanism, and
biocompatibility of the capped-MSN systems with animal and plant cells and tissues have
been investigated. For example, a MSN material with a large average pore diameter (5.4
nm) has been designed to serve as a transmembrane, controlled release carrier for a
membrane impermeable protein (cytochrome c). We found that the enzymes released
from the MSNs are still functional and highly active. We discovered that the cytochrome
c encapsulated MSNs could be internalized by live human cervical cancer cells (HeLa)
and the protein could be released into the cytoplasm. Furthermore, we successfully
delivered both gene and its chemical inducer into cell wall containing plant cells/tissues
and triggered gene expression under controlled-released conditions. We envision that
these MSNs can serve as a universal transmembrane vehicle for many biotechnological
applications including therapeutics and metabolic manipulation of cells.
POLYSACCHARIDE-BASED NANOGELS FOR SUSTAINED DRUG
DELIVERY
Eun S. Gil,1 and Tao L. Lowe1,2,3, Departments of Surgery,1 Bioengineering,2
and Materials Science and Engineering,3 Pennsylvania State University, 500
University Drive, Hershey, Pennsylvania 17033, USA; [email protected]
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The blood-brain barrier (BBB) is a dynamic and complex structure composed principally
of specialized capillary endothelial cells held together by highly restrictive tight
junctions. It allows the passage of nutrients into the brain, while preventing the passage
of many substances, posing a problem for cerebral drug delivery from the blood stream.
The primary objective of this study is to evaluate novel cationic and degradable βcyclodextrin nanogels as drug delivery carriers for insulin and doxorubicin across the
bovine brain microvessel endothelial cell (BBMVEC) monolayer, an in vitro blood brain
barrier (BBB) model. We use dynamic light scattering and FTIR to characterize the
particle sizes and degradation of the nanoparticles. We study the release kinetics of
insulin and doxorubicin from the nanogels. We investigate the permeability of the
nanoparticles without/with insulin and doxorubicin across the BBMVEC monolayer. Our
preliminary results demonstrate that the nanogels can sustain release of insulin and
doxorubicin, and showed 100% cell viability at the concentration of up to 500 μg•ml-1.
The nanogels are not only twice as permeable as 4 kD dextran control, but also enhance
insulin permeability across the BBMVEC monolayer.
Session I1 – Keynote Paper
SHAPING Au NANOPARTICLES: FROM SEEDS TO DECAHEDRONS FROM RODS TO OCTAHEDRONS
Isabel Pastoriza-Santos, Jorge Pérez-Juste, Ana Sánchez-Iglesias, Enrique
Carbó-Argibay, Benito Rodríguez-González, Luis M. Liz-Marzán
Departamento de Química Física, Universidade de Vigo, 36310, Vigo, Spain;
[email protected]
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85
Size and shape control are hot topics in both Colloid Science and Nanotechnology. In the
case of metals, size and shape control can be used as a means to tailor the optical
properties through modification of the plasmon resonance condition. Many synthetic
protocols have been published for metal nanoparticle synthesis, though simultaneous size
and shape control are still rare. We present here the controlled synthesis of extremely
regular gold nanocrystals through ultrasound-induced reduction of HAuCl4 on presynthesized seeds, using PVP as a stabilizing polymer. A strict relationship between the
final morphology and the crystalline structure of the seeds has been observed, with
formation of decahedra (pentagonal bipyramids) using penta-twinned Au seeds but single
crystalline octahedra using single crystal Pt seeds. The dimensions can be strictly
controlled through the ratio between the amount of seed and the HAuCl4 concentration,
and the monodispersity is as good as 10%. The optical properties of these particles can be
reproduced with a very good agreement by means of a model for the resolution of
Maxwell’s equations for bicones, so that a good correlation between particle size and
optical response can be established. Additionally, it will be shown that the shape of
(single crystal) gold nanorods can be finely tuned by controlled growth, again under
sonication in DMF, in the presence of PVP. Reshaping involves the formation of rods
with sharp tips and strongly faceted lateral faces, and ultimately leads to perfect, single
crystal octahedrons. Careful analysis of the morphological and crystallographic structure
of the different particles indicates that the growth rate on different facets follows the
order {111}<{110}<{100}, which requires PVP adsorption to alter the surface energies
of naked fcc faces. This result is thus in favour of a shape-inducing effect of the polymer,
through different binding interactions for the different faces, as has been previously
indicated by several authors. All these results are indicate that the crystallographic
structure of the seeds plays a key role in determining the final structure and shape of the
nanoparticles grown on them.
Session I1 – Invited Paper
MONODISPERSE ANISOTROPIC POLYMERIC MICROPARTICLES
SYNTHESIZED USING A MICROFLUIDIC DROPLET GENERATOR
Takasi Nisisako, Precision and Intelligence Laboratory, Tokyo Institute of
Technology, R2-6, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503,
Japan; [email protected]
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Microparticles with controlled anisotropies have myriad applications in a variety of
fields. Above all, microparticles having a biphasic geometry of distinct compositions and
properties, known as “Janus” particles, are attracting increasing attention of both
fundamental colloid science studies as well as industrial applications. Colloidal particles
with anisotropic shapes also have numerous applications; they can be used for modifying
optical properties, controlling rheological properties of suspensions, and building selfassembled composite materials. Here, we present a microfluidic droplet-generating
system for the fabrication of two types of monodisperse anisotropic polymer
microparticles: bicolored Janus microspheres with an electrical anisotropy and
nonspherical particles with tunable shapes. The microfluidic channel consists of a Yshaped channel and a sheath-flowing junction fabricated lithographically on a glass chip.
86
To produce the bicolored Janus microspheres, black and white acrylate monomers
(isobornyl acrylate) were infused separately into the two arms of the Y-junction to form a
two-color parallel stream. This two-color stream entered a shearing stream of a coflowing
aqueous phase, producing biphasic Janus droplets of two miscible phases by a shearrupturing mechanism (102–103 drops/s). We could vary the size of the Janus droplets in
the range of 50–200 μm by controlling the viscous shearing under the condition of a low
Capillary number. The droplets were highly monodisperse, typically with a coefficient of
variation around 2%. After the thermal polymerization outside the fluidic module, we
could obtain monodisperse Janus microspheres having black and white hemispheres. The
synthesized particles had an asymmetric charge distribution, and we could successfully
demonstrate the electric actuation of the synthesized particles for paper-like display
applications. To produce nonspherical particles, a photopolymerizable acrylate monomer
(1, 6-hexanediol diacrylate) and a nonpolymerizable organic phase (silicone oil) were
used, and we could produce monodisperse droplets comprising two immiscible organic
fluids in a coflowing aqueous stream. At equilibrium, the droplets formed a snowmanlike Janus geometry by the minimization of interfacial free energies among the three
liquid phases. Subsequent off-chip photopolymerization produced monodisperse polymer
particles with hemispherical shapes. The size and shape of the droplets and particles were
tunable through the variation of the flow conditions. Furthermore, we could massproduce the above-mentioned anisotropic polymer particles by the parallelization of 128–
256 microchannels on a chip.
Session I1 – Contributed Paper
LIQUID PHASE SYNTHESIS OF NANOPARTICLES
Richard Tilley, School of Chemical and Physical Sciences and MacDiarmid
Institute, Victoria University of Wellington,Wellington, NZ;
[email protected]
80
Liquid phase synthesis is a powerful method for the formation of uniform sized
nanoparticles and nanoparticles with a faceted morphology. General strategies for the
formation of catalytic platinum and palladium nanoparticles and quantum dots through
chemical synthesis will be outlined. The growth mechanism of how the particles form
will also be presented along with HRTEM observations. In-situ studies using synchrotron
radiation will also be discussed and the formation highly monodispersed nanocubes of
platinum and palladium.
Session I1 – Keynote Paper
PARTICLE MEDIATED CRYSTALLIZATION
Helmut Cölfen, Max-Planck-Institute of Colloids and Interfaces, Colloid
Chemistry, Am Mühlenberg, Research Campus Golm, D-14424 Potsdam,
Germany; [email protected]
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Crystallization is one of the basic procedures for materials synthesis. However, the last
decade has shown that crystallization does not necessarily proceed along the classical
textbook pathway of nucleation and subsequent addition of the atomar or molecular
species in a layer by layer growth process. Instead, nanoparticles can interact with each
other and mutually orient resulting in an aggregate with mutual crystallographic order.
The nanoparticles in such aggregate may crystallographically fuse to minimize their
surface energy leading to a single crystal. Such particle mediated crystallization pathway
is called “Non Classical Crytallization”. Nature also uses this pathway for the production
of Biominerals with complex shape, enhanced physical properties and single crystalline
behaviour. Some examples from Biomineralization and biomimetic mineralization will
introduce the concept. Furthermore, mechanisms leading to the mutual orientation of
crystalline nanoparticles in an aggregate resulting in mutual crystallographic order will be
discussed. Such particle mediated crystallization pathways greatly enhance the
possibilities of crystallization and morphogenesis.
CACO3 PARTICLE SHAPES AS RESULTING FROM AGGREGATION
OF NANOPARTICLES AND CONTROL BY POLYELECTROLYTES
Amane Jada, ICSI-CNRS 15 rue Jean Starcky, BP 2488-F-68057 Mulhouse,
France; [email protected]
82
Calcium carbonate (CaCO3) polymorphs such as calcite and vaterite of particles may
form in water in the presence of various anionic polyelectrolytes. However, in the present
work, the vaterite fraction may be obtained and stabilized depending on the polymer
concentration and structure. Further, in the crystallogenesis process, the polymer interacts
with the growing crystals and leads to control of crystalline structure, shape and size of
CaCO3 crystals. Such interactions result in a retarding effect on CaCO3 nucleation and
growth, as evidenced by an increase of the induction time. The final CaCO3 particles are
found to result from the aggregation of nanocrystals, and have various shapes depending
on polymer concentration and structure. It comes out that the properties of CaCO3
particles prepared in the presence of the polymer are function of the interaction efficiency
between the polymers anionic repeating units and the calcium ions.
SURFACE-FUNCTIONALIZED INORGANIC-ORGANIC MULTILAYER
PARTICLES: SYNTHESIS, SCIENCE AND APPLICATIONS
Hervé Dietsch, Vikash Malik, Camille Dagallier, Frank Scheffold and Peter
Schurtenberger, FriMat, Fribourg Center for Nanomaterials, Switzerland,
[email protected]
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We demonstrate the exciting possibilities for size and shape control of surfacefunctionalized particles that we can achieve when playing with a variety of physical and
chemical control parameters (nature of precursor, concentration, pH, temperature, ionic
force…). We focus on the synthesis of colloidal ZnO and α-Fe2O3 (hematite) particles.
We demonstrate full control of the particle shape from round, raspberry-like, cubical to
anisotropic spindle-like particles with variable axial ratios. These particles can then be
coated with a silica layer, allowing for the creation of a specific surface functionality for
their incorporation in polymer matrices or simply for their stabilization in a desired
solvent. We also show that an additional coating step with an organic coating using
dispersion polymerization or controlled polymerization from the surface of the silica
coated hematite is possible, leading to core-shell-shell particles with interesting surface
properties. We finally present results from applications of these versatile particle toolbox
to microrheological investigations of complex soft matter systems, studies of colloid
crystal and glass formation and creation of nanocomposites with tailored properties.
NANOMATERIALS AT INTERFACES: WET CHEMICAL ROUTES FOR
SIZE, SHAPE AND ORIENTATION CONTROLLED NANOPARTICLES,
Yuval Golan, Department of Materials Engineering and the Ilse Katz Institute
for Nanoscale Science and Technology, Ben-Gurion University, Beer-Sheva
84105, Israel; [email protected]
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Semiconductor nanostructures have attracted interest for reasons such as anisotropy of
material properties via shape control, size-dependent quantum confinement effects, and
as building blocks in nanoscale devices. "Wet" chemical routes for synthesis of
semiconductor nanostructures are straightforward and cost-effective and can result in
highly uniform nanomaterials with precise size and shape control. Three synthetic
methods will be presented, all in which interfacial processes play a major role. The first
method takes advantage of the air-water interface in the presence of ultrathin
polyconjugated organic films as a unique medium for synthesizing highly aligned
nanoparticles of, e.g., PbS and CdS, and their assembly into ordered structures. The
second technique will highlight highly uniform nanorods and nanowires of ZnS, CdS and
ZnSe capped with alkylamine surfactants, and will focus on the role of the organic
surfactants in controlling their structure and assembly into 2D and 3D super-structures.
Finally, chemical bath deposition also offers a simple and versatile route for producing
high quality PbSe and PbS thin films directly onto GaAs single crystal substrates without
the use of organic ligand molecules. A wide range of microstructures is obtained, from
nanocrystalline films to epitaxial single crystal films. Along with conventional in-house
characterization techniques, in-situ techniques such as laser light scattering and small
angle synchrotron x-ray diffraction are employed for monitoring growth and ordering in
real time.
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VARIOUS LAYERED DOUBLE HYDROXIDE MORPHOLOGIES
OBTAINED THROUGH SOLVOTHERMAL SYNTHESIS DIRECTED BY
AMINO ACIDS
Vanessa Prevot, Christine Taviot-Guého, Nathalie Gaillard-Caperaa, Claude
Forano; Laboratoire des Matériaux Inorganiques, Université Blaise Pascal,
UMR 6002, 24 Avenue des Landais, 63177 Aubière Cedex, France,
[email protected]
85
In recent years, Layered Double Hydroxides (LDHs) have attracted considerable
attention because of their potentially numerous applications for catalysis, polymer
formulation, chemical or drug storage and delivery and environmental remediation
processes. These materials are described by general formula [MII1-xMIIIx(OH)2] [AmII
2+
2+
2+
2+
2+
III
3+
3+
3+
3+
x/m.H2O] with M = Mg , Zn , Ni , Co , Cu ..., M = Al , Cr , Fe , Ga ...) and A
= inorganic or organic anions. The great variety of metal and interlayer species
combinations allows to tailor their physical (magnetic, optical, electrochemical) and
chemical properties (redox and acido-basic properties). Although it is generally admitted
that morphology has a great effect on the LDH performances, only few studies are related
to the control over the shape, particle size, surface area and porosity of LDH materials.
Because of their fairly low natural occurrence, LDH are generally synthesized by
coprecipitation or homogeneous precipitation with urea. In this work, we report a novel
synthetic process leading to three dimensional nanostructures of NiAl-based LDH
(flowerlike, pomponlike, ball…). This synthetic approach is based on the precomplexation of the transition metal ions with amino acid molecules and the metal
complex thermolysis under hydrothermal treatment. Reaction parameters such as reaction
time, reaction temperature, concentrations and nature of the amino acid are found to be
crucial in controlling the final composition, structure and morphology. Sacnning electron
microscopy, UV-VIS, FTIR spectroscopy, thermogravimetry analysis and X-Ray
diffraction are adopted to investigate the evolution process of Ni precursors. The
morphology variations were interpreted based on the amino-acid precursor nature and its
decomposition pathways. Details of the synthesis and characterization of the materials
generated there from will be presented in comparison with the growing process involved
during classic coprecipitation and homogenous precipitation. Finally, since the
morphologies are maintained under thermal treatment, this strategy allows also the
preparation of 3D structured mixed oxides.
Session J1 – Keynote Paper
SURFACE MODIFICATION OF SILICA NANOPARTICLES AND SIWAFER THROUGH SURFACE INITIATED CONTROLLED RADICAL
POLYMERIZATION, Atsushi Takahara, Yuki Terayama, Hiroki
Yamaguchi, Yasuhiro Matsuda, Motoyasu Kobayashi, Institute for Materials
Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 8190395, Japan, [email protected]
86
Surface-initiated polymerization from a solid surface is one of the promising methods to
modify wetability, adhesion behavior, and frictional properties on the surface of
inorganic sokids and particles. Controlled radical polymerization technique have been
90
applied to surface-initiated polymerization system, giving a tethered polymer with high
graft density and controlled molecular weight, a so-called "polymer brush". In this study,
hydrophilic and hydrophobic polymer brushes with 10~ 40 nm thickness were prepared
on the Si-wafer and silica nanoparticles by surface-initiated atom transfer radical
polymerization (ATRP) of various vinyl monomers with different functional groups.
Poly(vinyl alcohol) (PVA) brush was prepared by surface-initiated iodide transfer
polymerization of vinyl acetate (VAc) from a silicon wafer, and successive hydrolysis of
acetyl groups. The difference in adhesion force between PVA and PVAc brush surfaces
was confirmed by force microscopy. Zwitterionic poly(2-methacryloyloxyehtyl
phosphorylcholine) (PMPC) brush was also prepared by surface-initiated ATRP. PMPC
brush showed extremely high hydrophilicity and water lubrication. The polymer chain
conformation at the heavy water interface of PMPC brushes were characterized by
neutron reflectivity. It was revealed that the PMPC chain was stretched to the water phase
as well as high ionic strength aqueous solutions. The small influence of ionic strength on
chain conformation was also observed for the water dispersion of PMPC-grafted Sinanoparticles. The highly water repellency surface was prepared by surfaced-initiated
ATRP of 2-(perfluorooctyl)ethyl acrylate (FA-C8). The PFA-C8 brush film showed
surface ordered FA layer at the outer most surface. However, PFA-C8 on the Sinanoparticle have higher crystallinity than brush film on Si-wafer.
Session J1 – Contributed Paper
OPTICAL LIMITING STUDIES OF “NECKLACE”-LIKE GOLD
NANOPARTICLES/POLYMER HYBRIDS
Qiu Dai, Xiong Liu, Jianhua Zou and Qun Huo, Nanoscience Technology
Center, Department of Chemistry, University of Central Florida, Orlando FL
32826; [email protected], [email protected]
87
Metal nanoparticles (Au, Ag) and quantum dots are among the most exciting
nanomaterials with promising applications potentials in biosensing, bioimaging, bioassay,
targetd drug delivery. However, a significant challenge in nanoparticles field is the
controlled chemical functionalizaiton of nanoparticles materials. Due to the presence of
multiple reactive sites on a nanoparticles surface, it is extremely difficult to control the
number and geometrical distribution of chemical functional groups on the nanoparticle
surface. Recently we developed a unique solid phase place exchange reaction to
synthesize gold nanoparticles with a single carboxyl functional group on the surface.
Using these monofunctional gold nanoparticles, we synthesized sophisticated
nanoparticles/polymer hybrid materials with necklace structure using a single step
chemical reaction. The optical limiting performance studies of “necklace”-like gold
nanoparticles/polymer hybrid using time-resolved spectroscopy will be elaborated in
details during this presentation.
Session J1 – Invited Paper
RAFT POLYMERIZATION FROM NANOPARTICLES
Brian C. Benicewicz, Yu Li, and Linda S. Schadler
NYS Center for Polymer Synthesis, Department of Chemistry and Chemical
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Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA;
[email protected]
Reversible addition-fragmentation chain transfer (RAFT) polymerization has been
applied to the controlled polymerization of various monomers under a wide range of
conditions to prepare polymer materials with predetermined molecular weights, narrow
polydispersities, and advanced architectures. The combination of the RAFT technique
with polymer grafting techniques has been widely used as an approach to modify the
nanoparticle surfaces with a variety of functional polymers. In our work, we developed
an approach for attaching a variety of RAFT agents to the surface of nanoparticles with
graft densities ranging from 0.01 to 0.68 chains/nm2. Using these surface-immobilized
RAFT agents, styrenic, acrylate, and methacrylate monomers could be polymerized on
the nanoparticle surfaces via surface-initiated RAFT polymerization in a controlled
manner. The availability of the wide range of graft densities allowed us to study the
polymer chain behavior in both the brush and mushroom regions. We have also utilized
click chemistry techniques to modify the surface of nanoparticles. Graft polymerization
of two azide-containing monomers was accomplished from the silica nanoparticle
surfaces via surface-initiated RAFT polymerization. The resulting polymer-grafted
nanoparticles contain a large number of reactive azido groups, which can be referred as
“massively reactive nanoparticles”. Examples of subsequent click funtionalization of the
nanoparticles will be presented.
SURFACE MOLECULAR STRUCTURE AND INTERACTION DESIGN
TO CONTROL DISPERSION BEHAVIOR OF NANOPARTICLES IN
ORGANIC SORBENTS
Hidehiro Kamiya, Murino Kobayakawa, Noriyuki Furukawa, Motoyuki
Iijima, and Mayumi Tsukada, Tokyo University of Agriculture and
Technology, Koganei, Tokyo 184-8588 Japan; Kenji Takebayashi, Shuji
Sasabe and Takehisa Fukui, Hosokawa Powder Technology Research
Institute, Shoudai Tajika, Hirakata-City, Osaka 573-1132 Japan;
[email protected]
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Aggregation and dispersion behavior control of nanopartucles in liquid suspension is one
of the important technologies to apply nanoparticles in many fields, for examples,
material, pigment, cosmetic and drug delivery systems. In this research, in order to
develop the uniform dispersion of inorganic functional nanoparticles in organic liquid
suspension, some kinds of approach were investigated by the control of surface
interaction between nanoparticles based on the surface molecular and nanometer scaled
structure design. In our first approach, the aggregates of inorganic oxide composite
nanoparticles with different microstructure were collapsed by beads milling and particle
surface was modified by silane coupling agent in organic sorbent with slight amount
addition of pH-controlled water simultaneously. Since composite oxide nanoparticles
were prepared and collected by dry process and hydrophilic surface molecular structure,
large agglomerates were formed in organic sorbents. When the optimum milling and
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surface modification conditions were selected, 90 wt % aggregates of oxide composite
nanoparticles were able to be dispersed up to primary particles. In next approach,
surfactant with different molecular structure was adsorbed on the surface of uniform
dispersed TiO2 nanoparticle in aqueous suspension, the aggregates of nanoparticles were
formed and precipitated in aqueous solution by the adsorption of surfactants. The
separated aggregates from aqueous solution were dried and dispersed into organic
solvents. If the optimum surface molecular structure was designed by the selection of
molecular structure of surfactant, nanoparticles were dispersed up to primary particle in
various kinds of organic solvents. Finally, the relationship between surface molecular
structure and surface interaction in each organic solution was characterized by a colloid
probe AFM method, and discussed the action mechanism of silane coupling agent and
surfactant.
COMPLEX PARTICLE COATINGS FROM BLOCK COPOLYMER
MICELLE MULTILAYER FILMS
Simon Biggs, Institute of Particle Science and Engineering, University of
Leeds, Clarendon Road, Leeds LS2 9JT, UK; [email protected]
90
The modification of surfaces using polymer coatings has a long history and continues to
provide a fruitful area for technology development and academic study. The purpose of
such coatings is varied and includes surface protection, improved aesthetic qualities,
increased environmental acceptance and controlled wetting properties. In aqueous
particle dispersions, the ability to modify particle properties using steric polymer layers
has also received considerable interest over many years. The primary reasons for using
such polymer films are to improve particle dispersion stability, to improve the
formulation characteristics for the particles, and to improve the acceptance of particles in
medical applications. Recent advances in this area include the development of complex
films through the so-called layer-by-layer (LbL) deposition of polymers and/or
nanoparticles to provide highly functional coatings. In our research, we have been
investigating the development of an alternative class of polymer coatings based on block
copolymer micelles. Using oppositely charged micelles we are able to deposit complex
films using the LbL approach consisting exclusively of copolymer micelles. These films
are highly functional and provide a wide range of application possibilities. In this paper,
the characterization and analysis of these films on particle substrates will be described.
Evidence for the local structure within the film will be given showing clearly that the
micelle structures are retained within the films. The development of capsules using such
films will also be discussed using both particles and emulsion droplets as templates.
Finally, possible applications for coatings of this type on particle substrates will be
discussed.
NANOPARTICLES AS TOOLS FOR CONTROLLING CELL FUNCTIO.
V. Prasad Shastri, Department of Biomedical Engineering, Vanderbilt
91
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University, Nashville, TN 37232, USA; [email protected]
The full realization of the potential of stem and pluripotent cells in therapeutic
applications such as organ regeneration and other cell-based therapies is dependent in
part on developing a set of tools to control the differentiation of these cells into germ
layer-specific and tissue-specific phenotypes. The most common strategy involves the
use of soluble signals such as peptides and growth factors, in combination with
extracellular matrix components, to trigger signaling cascades that promote
differentiation. It is well known that cell shape and function are coupled. At the
fundamental level the impact on cell function through changes in cell shape, is driven by
events that influencin the interaction of the cell membrane with the substrate. This in turn
impacts sub-cellular structures and processes through mechano-transduction. Cell
membrane-surface interactions are influenced by surface chemistry, topography and
spatial distribution of information. We recently demonstrated that biomaterial surface
and chemistry can be independently and reproducibly modulated using an assembly of
functionalized nanoparticles. In this talk, the potential of nanoparticle assemblies as a tool
for impacting cell structure and function, and cytoskeletal organization in particular, will
be elucidated. Furthermore, the impact of such changes in lineage specific differentiation
of human progenitor cells will be explored.
SURFACE MODIFICATION OF POLYISOBUTYLENE-BASED
MEDICAL DEVICE COATINGS USING ELECTRONANOSPRAY™.
Robert Hoerr and John Foley, Nanocopoeia, Inc., St. Paul, MN 55104, Greg
Haugstad and Jinping Dong, Institute of Technology Characterization
Facility, University of Minnesota, Minneapolis, MN and Judit Puskas,
Department of Polymer Science, University of Akron, Akron, OH, USA;
[email protected]
92
Coronary drug-eluting stent coatings have been associated with late-term thrombosis,
raising questions about the local vascular response to the drug-polymer matrix after
prolonged implantation. We have developed a comprehensive approach for creating
novel drug-eluting coatings and evaluating their nanoscale and biological behavior.
ElectroNanospray™ is a novel process that can be used to apply nanoparticles of various
combinations of drugs and polymers to the surface of intricate medical devices, such as
coronary stents. Using ElectroNanospray, a variety of surface morphologies have been
achieved using a third generation drug-eluting polymer, arborescent polyisobutylenepolystyrene block co-polymer (arbIBS), and model drug dexamethasone, ranging from
apparently smooth conformal films when imaged by scanning electron microscopy
(SEM) to films that are composed of loosely packed nanoparticles. In addition, multilaminate films where each layer had a unique morphology were applied. While these
different morphologies and combinations alter the rate of drug release as measured by
HPLC, little is known about the way that nanoparticulate deposition might alter the time
course and manner by which these poorly soluble drugs are released from these coatings.
Using complementary techniques of atomic force microscopy (AFM) and confocal
Raman microscopy, the real-time course of drug release was imaged, with baseline
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images in room air and subsequently throughout prolonged incubation in a buffered salt
solution. Apparently homogeneous films by SEM demonstrated more concentrated areas
of drug deposition on the surface and throughout the film depth as imaged by confocal
Raman. The fine structure of corresponding surface area, examined with AFM, showed
nanoscale (~100 nm) drug particles within the surrounding polymer matrix. Post –
incubation, SEM documented porous areas in materials that had previously appeared
homogeneous. To evaluate the biological response to these novel coatings, we are using
a novel atherosclerotic mouse model of balloon angioplasty and stenting, utilizing a
“nano”stent that can be coated and implanted to observe how the coating performs in the
intravascular setting. The ElectroNanospray process offers a high degree of
compositional control for coatings made using these new polymers. These advanced,
complementary imaging techniques provide rapid understanding how therapeutic agents
are released from a coated implant’s surface. The mouse stent model provides a tool for
showing how manipulation of surface composition, morphology and drug release might
improve the biological response at the cellular interface between stent and arterial lumen.
HYDROLYSIS-INDUCED IMMOBILIZATION OF Pt(AcAc)2 ON
POLYIMIDE NANOFIBER MAT IN THE FORMATION OF Pt
NANOPARTICLES
Nguyen Thi Xuyen, Gunn Kim, Hae Kyung Jeong, Kyung Ah Park, Eun Ju
Ra, Min Ho Park, Cheol Woong Yang, Kang Pyo So, Kay Hyeok An, Young
Hee Lee, Center for Nanotubes and Nanostructured Composites,
Sungkyunkwan University, Suwon 440-746, Korea, School of Advanced
Materials and Engineering, Sungkyunkwan University, Suwon 440-746,
Material & Development Department, Jeonju Machinery Research Center,
Jeonju 561-844, Korea; [email protected]
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Pt nanoparticles have been formed on the polyimide (PI)-based nanofiber mat via
carbonization. The PI nanofiber mat was obtained from the electrospun poly(amic acid)
(PAA) nanofiber mat after stabilization. Pt(acac)2 (acac - acetylacetonate) powder was
dissolved in acetone with hydrolyzed PI nanofiber mat. The PI nanofiber mat was further
carbonized to form Pt nanoparticles on the nanofiber surface. Pt nanoparticles were
uniformly located over the carbon nanofiber surface with a size of 3 nm in average. The
particle size was controllable by the heating rate and carbonization temperature. Our xray photoelectron spectroscopy shows that Pt ions in Pt(acac)2 molecules are mostly
immobilized on the hydrolyzed PI surface while some of them (60 %) are released from
(acac) to bind to carboxylic group, and then fully decomposed into Pt nanoparticles
during carbonization. Based on the density functional theory, we calculated a Pt(acac)2
molecule on PAA (or PI). In the case of Pt(acac)2-PI, -stacking type adsorption is
preferred and ~0.4 e are transferred from Pt(acac)2 to PI. On other hand, for Pt(acac)2PAA, Pt(acac)2 adsorbed near oxygen side group in PAA, and electron transfer is ~0.05 e.
The cyclic voltammetric test demonstrates that our robust carbon nanofiber mat can be
utilized for fuel cell electrodes.
Session K1 – Keynote Paper
95
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BIOLOGICAL ACTIVITY OF MINERAL FIBERS AND CARBON
PARTICULATES: IMPLICATIONS FOR NANOPARTICLE TOXICITY
AND THE ROLE OF SURFACE CHEMISTRY
Prabir K. Dutta1 John F. Long2, Marshall V. Williams3 and W. James
Waldman4,1Departments of Chemistry, 2Veterinary Biosciences, 3Molecular
Virology, Immunology and Medical Genetics and 4Pathology, The Ohio
State University, Columbus, Ohio 43210 USA; [email protected]
We discuss our work on the correlations between biological activity and physicochemical
characteristics of minerals and particulates. Naturally occurring zeolite called erionite is
highly toxic and causes mesothelioma and is more carcinogenic than crocidolite asbestos.
No other zeolites, including mordenite have toxicities as large as erionite. For erionite,
its toxicity is commonly associated with the iron that accumulates on its surface via ionexchange following its deposition within the lungs. Mordenite also has ion exchange
abilities and to some extent a fibrous morphology. However, it is not carcinogenic. Thus,
the difference in the biological and chemical reactivity of these two minerals provides
insight about mineral toxicity. For assessment of biological response, phagocytosis as
well as the oxidative burst as a result of phagocytosis by rat pulmonary alveolar
macrophage-derived cells was examined. Ultrastructural studies of cells showed marked
variation in size and numbers of the phagocytized particles. Reactive oxygen metabolite
generation within a cell was noted upon phagocytosis. Extracellular release of oxygen
species was measured via luminol chemiluminescence. The ability of the iron-exchanged
forms of the zeolites to produce hydroxyl radicals from H2O2 (Fenton reaction) was
studied. Mordenite was not mutagenic. Conversely, erionite was mutagenic in a doseresponse manner and the mutagenic potential of erionite was significantly enhanced by
the addition of ferrous ions. To identify specific particulate physicochemical
characteristics which determine bioactivity, we synthesized 1 μm or 100 nm carbonbased model particulates with or without surface Fenton-reactive iron. Internalization of
all particulates, including coal fly ash and diesel emission particulates, by freshly isolated
and differentiated human monocyte-derived macrophages (MDM) was verified by phasecontrast microscopy and transmission electron microscopy. The differential ability of the
various particulates to induce oxidative stress in MDM was determined by luminol
chemiluminescence assay of the generation of extracellular reactive oxygen species in
response to particulate exposure. Human endothelial cells isolated from various vascular
beds were incubated with supernatants recovered from cultures of particulate-treated
MDM, and assayed for induction of inflammatory endothelial adhesion molecule
expression by immunofluorescence flow cytometry. While supernatants of MDM treated
with coal fly ash or pure carbon particulates demonstrated little impact upon endothelial
inflammatory activation, those recovered from MDM treated with diesel emission
particulates or synthetic carbon particulates bearing surface iron induced high levels of
endothelial adhesion molecule expression in a dose-dependent manner. Notably, per unit
mass, 100 nm carbon-iron particulates were far more effective in endothelial
inflammatory activation than their 1 μm counterparts. These studies have relevance to the
environmental impact of engineered nanomaterials, including toxicity of fibrous carbon
nanotubes and diesel exhaust particulates, carbon black and fullerenes.
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Session K1 – Invited Paper
PARTICULATE SUSPENSIONS OF ETTRINGITE FOR REMOVAL OF
BORON COMPOUNDS FROM AQUEOUS SOLUTIONS
Nava Narkis and Svetlana Yusim – Bandel; Environmental, Water and
Agricultural Engineering, Technion, Israel Institute of Technology, Haifa
32000, Israel; [email protected]
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Boron is an essential nutrient for vegetation at low concentrations, however, boron is
toxic to plants at certain concentrations, but varies with species and climate factors. It
can be damaging to crops if present in irrigation water. In view of the shortage in natural
water resources, reuse of treated effluents, mainly for irrigation, is practiced. The
presence of high concentrations of boron compounds in treated effluents limits the
application of reused effluents for irrigation of plants and vegetation sensitive to the
presence of boron. The boron compounds in effluents originate from water supply and
from natural sources in soil, while the main part is derived from the detergents, found in
household laundry and dish washing powders, using perborate as the single most
important bleaching component. Boron concentration is not affected by the conventional
treatment processes of water and wastewater. Thus, all the boron entering the water
systems and added through domestic use finds its way to the treated wastewater. Boron
concentrations in drinking water and wastewater are likely to increase with the entrance
of sea water desalination processes for potable water, since boron compounds are not
readily removed through reverse osmosis. Therefore, it is necessary to apply expensive
multi – stage RO membrane treatment systems for producing finished water, which
meets the WHO drinking water quality guidelines level for boron. The main purpose of
this research was to study the use of ettringite particulate suspensions for removal of
boron compounds from controlled synthetic aqueous solutions and effluents for reuse in
irrigation. Ettringite is a mineral with the formal equation Ca6Al2(OH)12(SO4)3·26H2O.
The ettringite particulate suspensions, produced in the reactor, by the reaction of
aluminium sulfate and calcium hydroxide, efficiently remove boric acid and boron
compounds up to complete removal. It was found that incresing the ettringite dose
and contact time significantly improved boric acid removal efficiency. From the
linearized form of the Langmuir adsorptoin isotherms, the maximum adsorption capacity
value Qmax = 2.17 mg B/ g ettringite and the energy parameter b were determined.
Ettringite particulate suspensions formed in effluents entirely removed boron and
phosphorous compunds, the colloidal and suspended solids obtaining good clarification.
In addition, the ettringite removed a part of the soluble organic contaminants from the
effluents. After exposure of the ettringite particulates to an aqueous solution of boric
acid, the used ettringite particulates were separated by centrifugation and re-suspended,
without any treatment, in a new aqueous solution of boric acid. This process was repeated
4 times, each time the same used ettringite particulates were separated and re-suspended
in a new aqueous solution of boric acid, continuing to efficiently remove boron
compounds.
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Session K1 – Contributed Paper
CONTROLLING UPTAKE AND INTRACELLULAR FATE OF
SURFACE-MODIFIED COLLOIDAL GOLD
1
Paola Nativo, 2Ian Prior and 1Mathias Brust; 1Department of Chemistry,
2
Physiological Laboratory, The University of Liverpool, Liverpool L69 7ZD,
United Kingdom; [email protected]
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The use of metallic nanoparticles in biomedical sciences has witnessed increasing interest
over the past few years. Such applications include, for instance, the detection, diagnosis
and treatment of tumours, targeted gene and drug delivery, and labelling of intracellular
structures. The interaction between the nanoparticles and the living cells is regulated by a
complex dynamics, the understanding of which is of crucial importance to foster further
developments in this field. There is consensus that spontaneous cellular uptake is
governed by the endocytotic process whereby invaginations of the plasma membrane
embrace nanoparticles into vescicles, i.e. endosomes. For many applications of interest,
however, endosomes do not represent a favourable environment, as nanoparticles are
prevented from reaching desirable targets such as the nucleus, mitochondria and the
endoplasmatic reticulum. Here we present a systematic electron microscopic
investigation of three different strategies for stabilised gold colloids to escape the
endosomic pathway in a human fibroblast cell line (HeLa). First, we employed
commercially available liposomes to encapsulate gold nanoparticles and deliver them by
fusion with the plasma membrane. Although endocytosis was not suppressed, the
presence of liposomes appeared to trigger another mechanism, which consists of the
formation of caveolae, flask-shaped invaginations of the plasma membrane. This strategy
resulted in a fraction of nanoparticles being freely dispersed in the cytoplasm. Second, we
investigated the use of ultrasound as a potential method of stimulating cellular uptake.
We performed experiments using a range of gold nanoparticles with various ligand shells,
of which we had established different responses to spontaneous incubation. We found
that sonication permitted the uptake of nanoparticles that otherwise would not be taken
up spontaneously. We also observed free dispersion in the cytoplasm of those types of
nanoparticles that otherwise would be taken up spontaneously and trapped in the
endosomes. Third, we studied the modification of the particle surface with so-called
membrane penetration factors (i.e., oligopeptides TAT and Pntn) as a means to facilitate
the direct transfer of particles across the membrane. Again, in addition to particles
trapped in the endosomes, a significant fraction of particles was found in the cytoplasm.
As a further step towards the targeting of specific cell organelles, we added another
peptide, Nuclear Localisation Signal (NLS), to the ligand shell. As well as in the
endosomes and in the cytoplasm, we now also observed the presence of nanoparticles in
the nucleus. Furthermore, a larger proportion of particles was found to group in the
proximity of the nucleus. Interestingly, such nanoparticles were associated to previously
unobserved membrane structures which resemble destroyed endosomes. Although still
unclear, this finding suggests the existence of an endosomal trafficking pathway from the
plasma membrane to the nucleus.
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BACTERICIDAL ACTIVITY OF SOLVENT-FREE NANOFLUIDS
Daniel Clemans,† Rola Amad,‡ Zhiming Qiu,‡ and John Texter,‡ †Biology
Department and ‡School of Engineering Technology, Eastern Michigan
University, Ypsilanti, MI 48197, USA; [email protected]
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Solvent-free nanofluids, such as those invented by Giannelis and co-workers, are being
further modified and incorporated into nanocomposites and other new materials. Further,
with the advent of nanotechnology, quite a bit of concern is being expressed about the
toxicity of new materials. Many of these solvent-free nanofluids are essentially a new
class of supramolecular ionic liquids, and most of these new nanofluids are surface
functionalized with quaternary molecules and organic salts. Quaternary salts are well
know to exhibit antimicrobial activity; we examined several sample nanofluids to see if
they indeed are bactericidal. Most of our tests were done in challenges against a
representative Gram-positive (Staphylococcus aureus) and Gram- negative bacterium
(Escherichia coli). Minimum inhibitory concentrations (MICs) and minimum bactericidal
concentrations (MBC) for each nanofluid were determined using standard methods. Some
of the sample nanofluids exhibited MICs in the range of 30-38 μg/ml agains S. aureus,
putting their performance in the same league as the well known antibiotic, ampicillin.
Activity against E. coli was generally much less, although one of the examples had an
MIC of 47 μg/ml. Results for nanofluids decorated with methyldidecylammonium
sulfonates (I) and methyldecylimidazolium sulfonates (II) will be presented, along with
results for nanofluids I also decorated with amino and acryl functional groups. The
greater activity against S. aureus over E. coli is tentatively ascribed to the Gram-negative
cell wall structure. The 8-9 nm diameters of these surface modified nanoparticles cannot
exhibit molecular scale diffuison through aqueous polymer nets because of their
supramolecular size and 7 nm diameter silica core.
Session K1 – Invited Paper
PRECLINICAL IMMUNOLOGICAL NANOPARTICLE
CHARACTERIZATION
Marina A. Dobrovolskaia and Scott E. McNeil, Nanotechnology
Characterization Laboratory, Advanced Technology Program, SAICFrederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA;
[email protected]
98
The unique physicochemical properties of nanosized particles make them attractive
candidate drugs or drug carriers. A nanoparticle’s interaction with immune cells and
plasma proteins may influence its biodistribution and drug delivery, so identifying the
physicochemical properties which determine this interaction is an important part of
preclinical development of nanoparticle-based drugs. This presentation discusses in vitro
methods for identifying the properties of nanoparticles which influence the immune
system, gives an overview of some of the properties that have been shown to influence
immune system biocompatibility thus far, and details current challenges in the preclinical
immunological evaluation of nanoparticles. Funded by NCI Contract N01-CO-12400
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SAPHIR (EUROPEAN PROJECT): SAFE, INTEGRATED &
CONTROLLED PRODUCTION OF HIGH-TECH MULTIFUNCTIONAL
MATERIALS AND THEIR RECYCLING
Christophe Goepfert, CEA Programs & Development, CILAS, 8, Avenue
Buffon - B.P. 6319, ZI La Source, 45063 Orleans Cedex, France;
[email protected]
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Industrial needs in terms of multifunctional components are increasing. Several sectors
are concerned, ranging from mature high volume markets like automotive applications,
high added value parts like space & aeronautic components or even emerging activities
like new technologies for energy. Also are concerned domains with a planetary impact
like environment and new products and functions for health and safety of people.
Nanotechnologies could play a key role in promoting innovation in design and realisation
of multifunctional products for the future, either by improving usual products or creating
new functions and new products. Nevertheless, this huge evolution of the industry of
materials could only happen if the main technological and economic challenges are
solved with reference to the societal acceptance. Those concern the mastering, over the
whole life cycle of the products, of the potential risks, by an integration of the elaboration
channels, while taking into account recycling.
LOCALISATION OF QUANTUM DOTS WITHIN CELL
COMPARTMENTS IS DEPENDENT ON THE SIZE OF THE PARTICLE
AND ON THE CELL LINEAGE
Yvonne Williams1, Alyona Sukhanova2, Anthony Davies1, Igor Nabiev2,
Dermot Kelleher2, Yuri Volkov1, 1Department of Clinical Medicine, Trinity
College Dublin, Ireland; 2University of Reims, France; [email protected]
100
How the living organism interacts with foreign particles is very much dependent on the
size and shape of the particle. Engineered nanoparticles are found in an increasing
number of applications in the biomedical sciences. Semiconductor nanocrystals or
quantum dots (QDs) in particular may be very useful in the tracking of molecules in vivo.
However the potential harm of these nanoparticles is still poorly understood. Recent
studies have shown that change in NP size and shape can alter interactions with living
cells and thereby affect toxicity. In this report using QDs of various sizes we examine the
compartmentalisation of the QDs in three different cell lineages namely THP-1
(macrophage) cells, HEp-2 (epithelial) cells and AGS (endothelial) cells, that would be
representative of the most likely environmental exposure routes in humans. The cells
were fixed and permeabilised prior to the addition of the QDs thereby eliminating any
effects due to active QD uptake mechanisms or to specificity of signalling routes in
different cell types. All assays were performed using a High Content Analysis (HCA)
platform, thereby getting robust data on large cell populations. We demonstrate that while
the smaller QDs enter the nuclei and locate to the nucleoli in all of the three cell types,
100
the rate and passage differ depending on cell type. Furthermore as QD size is increased,
penetration into the cell is reduced but each cell line had its own cut-off size reflecting
cell-type determined nuclear pore size specificity. This gives rise to an important
consideration regarding the susceptibility of certain organs, tissues and cells to QDs and
may be of prime importance for biomedical imaging and drug delivery studies.
FUNCTIONAL MAGNETIC NANOPARTICLES AS BUILDING BLOCKS
OF NOVEL BIOMATERIALS
Lyudmila Bronstein1, Xinlei Huang1, Jason Dyke1, Hu Cheng2, and Bogdan
Dragnea1, Departments of Chemistry1 and Psychological & Brain Sciences 2,
Indiana University, Bloomington, IN 47405, USA; [email protected]
101
Monodisperse magnetic nanoparticles (NPs) can be successfully functionalized and
hydrophilized due to hydrophobic interactions with amphiphilic molecules such as
phospholipids with poly(ethylene glycol) tails or amphiphilic polymers. The NPs with
carboxy terminal groups serve as templates for the formation of novel biomaterials:
magnetic virus-like particles (VLPs) based on Brome Mosaic Virus (BMV) proteins.
Judging by the shell size, the BMV proteins form a single protein layer similar to wildtype virus despite a much larger size of the internal cavity/template. The VLPs derived
from the magnetic NPs preserve their magnetic character. Injection of magnetic NPs into
the plant leaves allows monitoring the particle diffusion via magnetic resonance imaging
(MRI). Because an MRI image is created at low concentration of NPs, these VLPs are
highly promising MRI contrast enhancement agents with well adjustible functional
exterior.
STRUCTURAL CHANGES IN CARBON-POLYMER COMPOSITES BY
EXOTHERMIC EFFECTS INDUCED BY ELECTRIC FIELDS
Masaru Matsuo, Setsuko Isaji, Qingyun Chen, Nara Women’s University,
Nara 630-8506 Japan; [email protected]
102
Improvement in reproducibility of electrical conductivity for carbon-polymer
coomposites was achieved by using ultra-high molcular weight polyethylene
(UHMWPE) and poly(vinylalcohol) (PVA) as polymer matrix. The origin of the positive
thermal coefficient (PTC) phenomenon was found to be due to the distribution change of
the interparticle gap between carbon fibers in the molten state of the polymers. This
tendency was enhanced when carbon fibers were plated by thin nickel layer. The
temperature on the composite surface due to exothermic effect was confirmed even at
1.5V, when content of carbon fibers against polymer matrix is beyond the critical
concentration. With increasing voltage, the temperature increased and reached 150oC for
UHMWPE and 250oC for PVA close to their apparent melting point. The current and
voltage showed a linear relationship. However, when the temperatures increased close to
their melting point, the drastic temperature decreases were observed, which was found to
be due to the chain scissions. The crystallinity of polymer matrix was measured by X-ray
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diffraction under the applied electric field. The crystallinity decreased with elapsing time
because of the melting of the polymer matrix by exothermal effect. The thermal
expansion between amorphous polymer chains was confirmed and this phenomenon was
related to PTC effect.
Session F2 –Contributed Paper
SIZE DEPENDENT MAGNETIC PROPERTIES OF POLYOL-MADE
CoFe2O4 NANOPARTICLES
Souad Ammar,1 M. Artus,1 F. Herbst,1 M-J. Vaulay,1 F. Villain,2 J-M.
Grenèche,3 F. Fiévet. 1
1
ITODYS, Université Paris 7, UMR-CNRS 7086, 2 Place Jussieu 75251
Paris, France ; 2LCI2M, Université Paris 6, UMR-CNRS 7071, 4 Place
Jussieu, 75251 Paris, France ; 3 LPES, Université du Maine, UMR-CNRS
6087, Avenue Messiaen, 72085 Le Mans, France ; [email protected]
103
The properties of materials composed of magnetic nanoparticles are a result of both the
intrinsic properties of them and the interactions between them. The study of the intrinsic
effects of finite size on zero-temperature spin ordering, magnetic excitations, and
relaxation in such particles have been severely compromised due to their low
crystallinity, in relation with the synthesis conditions. Very often, an important spin
glass-like surface and/or core occur in these particles and mask these intrinsic effects.
Moreover, some interparticules interactions may mask them as well. Highly crystalline
monodisperse nanoparticles of CoFe2O4 with different mean size ranging from 2.4 nm to
6.9 nm have been obtained by the well known polyol method. The size of the particles
has been controlled by adjusting the nominal Fe/Co and water/ metal molar ratios. A
selected sample of 5.5 nm particle in size has been further grown by thermal treatment to
reach an average crystal size of 9.9 nm. These particles exhibit clearly size-dependent
magnetic properties. They are superparamagnetic with a blocking temperature, TB, which
increases with particle size. Below TB, they are ferromagnetic with a high saturation
magnetization. Its value increases with the particle size, approaching that of the bulk for
the larger particles (~85 emu.g-1 at 5 K). They exhibit also a large coercivity. Its value
reaches a maximum (14.5 kOe at 5 K) for the 3.5 nm sized ones. These magnetic
properties appear to be due to structural and microstructural changes related to the
particle size decrease: a deviation of the cation distribution from that of the inverse spinel
structure and an increase of the surface/volume ratio. The influence of the dipolar
interparticle interactions seems to be negligible.
POLYMER AND INORGANIC NANOPARTICLES INTENDED FOR
BIOASSAYS
Mitchell A. Winnik, Department of Chemistry, University of Toronto,
Toronto, Ontario Canada M5S 3H6; [email protected]
104
This paper covers several topics. It will describe the synthesis of polystyrene
nanoparticles prepared by miniemulsion polymerization that contain typically 1000 to
2000 lanthanide ions per particle. The PS nanoparticles are taken up by lines of human
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leukemia cells and serve as codes for cell type. Taking advantage of ICP-mass
spectrometry detection, these labeled cells can be used to study chemically induced cell
differentiation and cell adhesion. These experiments are caried out in collaboration with
V. Baranov, and O. Ornatsky. A second topic, carried out in collaboration with G.
Scholes, involves the use of water-solbule polymers as multidentate ligands for for
tadtional colloidal quantum dots (QDs) such as CdSe, CdSe/ZnS, and PbS. I will present
recent work in which we use pulsed-gradient spin echo NMR to measure the extent of
ligand exchange when the as-synthesized QDS are treated with polymer in solution.
CONTROLLED CO-ASSEMBLY OF IRON OXIDE NANOPARTICLES
ANDPOLYMERS : TOWARDS THE GENERATION OF HIGHLY
PERSISTENTSUPERPARAMAGNETIC NANORODS
Jérôme Fresnaisa, Jean-François Berreta, B. Frka-Petesicb, O. Sandreb and R.
Perzynskib; aMatière et Systèmes Complexes, UMR 7057 CNRS Université
Denis Diderot Paris-VII,Bâtiment Condorcet, 10 rue Alice Domon et Léonie
Duquet, 75205 Paris, France; b Laboratoire Liquides Ioniques et Interfaces
Chargées, UMR 7612 CNRS Université Pierre etMarie Curie Paris-VI, 4
place Jussieu, F-75252 Paris Cedex 05 France; [email protected]
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During the past years, we have investigated the complexation between nanocolloids and
oppositely charged polymers. The nanocolloids examined were ionic surfactant micelles
and inorganic oxide nanoparticles. For the polymers, we used homopolyelectrolytes or
block copolymers with linear or branched architectures. The attractive interactions
between oppositely charged species are strong and in general the simple mixing of
disperse solutions results in a precipitation, or in a phase separation. Recently, we have
developed means to control the electrostatically-driven attractions and at the same time to
preserve the stability of the dispersions. Using this approach we have designed novel
nanostructures, as those obtained with iron and cerium oxide nanoparticles. In this
presentation, we give an account of the formation of colloidal and supracolloidal
aggregates obtained by controlled co-assembly of 7 nm particles with copolymers.
Nanostructured rods of length comprised between 5 and 50 µm and diameter 500 nm
were also disclosed. By application of an external magnetic field, the nanorods were
found to reorient along the magnetic field axis. Preliminary micro-rheology experiments
on test fluids have demonstrated the potential use of these nanostructured rods to
determine locally the viscoelastic response of complex fluids.
THE ROLE OF SURFACTANT INTERACTIONS IN THE MAGNETIC
PROPERTIES OF CHEMICALLY SYNTHESIZED NANOPARTICLES
AND NANOCOMPOSITES
Dale L. Huber, Sandia National Laboratories, Albuquerque, NM 87111,
106
The basic physics of nanomagents have been known for decades, and magnetic
nanoparticles in inert matrices or particles beams have been shown to conform to
103
predictions. As a practical matter, magnetic nanoparticles are generally synthesized in a
liquid matrix that is far from inert. The solvents and surfactants present in these solutions
have a profound effect on the magnetic properties of the resultant nanoparticles. These
effects are extraordinarily complex and are only beginning to be understood. I will
discuss a series of experiments designed to understand the impact of surfactant and
synthetic approach on the magnetic properties of nanoparticles, using iron nanoparticles
as a model system. Iron was chosen as a model since it is both highly magnetic and
highly reactive. In this system the choice of surfactant can alter measured values of
saturation magnetization and magnetocrystalline anistotropy by as much as an order of
magnitude. A variety of experimental data will be presented, along with probable
mechanisms for the surfactant role in the magnetic properties. Sandia is a multiprogram
laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United
States Department of Energy's National Nuclear Security Administration under contract
DE-AC04-94AL85000.
IRON OXIDE NANOPARTICLES PREPARED BY LASER PYROLISIS
FOR BIOMEDICAL APPLICATIONS
Virginia Bouzas and M. A. Garcia, Department Material Physics, University
Complutense at Madrid; [email protected]; R. Costo, M. P. Morales ands S.
Veintemillas-Verdaguer. Institute of Materials Science, CSIC, Madrid, Spain
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Small magnetic particles have attracted considerable attention owing to their
technological and scientific importance. Iron oxide nanoparticles are one of the most
suitable tools in biomedical applications because of their utilities as drug delivering,
labelling bioelements and contrast agent for magnetic resonance imaging. To fulfil all
these objectives it is necessary to tailor precisely their magnetic properties. As the
features of the nanoparticles are strongly depending on their structure, size and shape, it
is needed production methods which allow controlling the structural parameters and
therefore, the magnetic ones. Among the different methods that can provide this kind of
nanoparticles, laser pyrolysis has the advantage to produce homogeneous and uniform
material in quantities fairly larger than other chemical methods, which requires a much
longer time to produce few milligrams and, results more expensive, too. Furthermore, this
technique produces highly pure particles, a key condition for their use in biomedicine in
order to avoid secondary effects. Here, we report on the preparation and magnetic
characterization of Fe oxide nanoparticles by laser pyrolysis and the relationship between
the preparation conditions and the magnetic response. Iron oxide nanoparticles were
prepared by pyrolysis laser using a continuous CO2 laser with Fe(Co)5, as precursor, and
a mixture of C2H4-Air, as flux carriers. With this conditions, Fe oxide nanoparticles
with size below 6 nm were obtained. Magnetization curves were measured at 10 K and
Room Temperature (i.e., above and below the blocking temperature) and the thermal
dependence of the magnetization was registered for a 1000 Oe field. All the samples
presented superparamagnetic behaviour at 300 K. Results show that the magnetic
properties are mainly related to the degree of crystallinity of the samples and less
sensitive to the particle size. It is concluded that the size and the main structural and
magnetic characteristics of the nanoparticles (coercive force, saturation magnetization,
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anisotropy and blocking temperature) can be tuned in a wide range of values through the
synthesis conditions. Specially, the carrier flux is the most determining parameter.
BULK PRODUCTION AND MODIFICATION OF IINORGANIC
NANOWIRES FOR SOLAR ENERGY CONVERSION AND STORAGE
APPLICATIONS
Mahendra K. Sunkara, Chemical Engineering and Institute for Advanced
Materials and Renewable Energy, University of Louisville, KY 40292, USA;
[email protected]
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Highly crystalline nanowires and their architectures could allow for high surface area
platforms with fast electron transport for efficient solar energy conversion and Lithium
battery applications. So, processes for producing large quantities of nanowires with
control on size, crystallinity and their modification for producing new compositions are
critically needed. Over the last several years, our group demonstrated several nontraditional or catalyst-free synthesis methods for inorganic nanowires that can be scaled
up for both large scale production as well as creation of novel 3-dimensional
architectures. Recently, we succeeded in the scale-up of metal oxide nanowire production
by synthesizing them in the gas phase without the use of substrates. This new microwave
plasma reactor has the capability to produce about a kg of nanowires per day and has
already been demonstrated for the synthesis of tin oxide, zinc oxide, titanium dioxide and
highly doped zinc oxide. The bulk produced metal oxide nanowires have been further
studied into various device applications such as dye sensitized solar cells,
photoelectrochemical water splitting and lithium batteries. Our studies showed that tin
oxide nanowires are promising materials for improving the performance of both tin oxide
and other nanoparticle based dye sensitized solar cells. Similarly, our studies with
Lithium battery tests show that nanowire based architectures could be used to generate
new materials that provide stable performance over hundred cycles of charge –discharge
with high capacity retention. In this presentation, we will highlight the bulk production
results; the modification of nanowires; and their behavior in dye sensitized solar cells and
lithium battery electrode applications.
Plenary 2
165
HOW TO GENERATE AND MANIPULATE NANOPARTICLES WITH
MINIMAL BIOLOGICAL IMPACT
Vicki L. Colvin, Rice University, Houston, TX , USA;
Abstract Unavailable
COMMERCIALIZATION OF SEMICONDUCTOR NANOPARTICLES
Clinton T. Ballinger, Evident Technologies, Inc., 216 River St., Troy, NY
12180, USA; [email protected]
166
Evident Technologies was the first company to commercialize semiconductor nanocrystal
105
back in 2002. These novel, tunable semiconductor nanocrystals can enable products
across many different markets. The sales of the materials were brisk and Evident
Technologies was able to tap into the pent-up demand. In 2006 Evident changed the
focus and organizational structure to create and support higher-value product line
development and commercialization. This change was driven by our feeling that these
nanomaterials would soon be commoditized and it would be difficult to sustain a
company on material sales alone. The transition from being a materials focused company
to being a product focused company has been interesting. This presentation will highlight
some of the trials and tribulation of this journey. One of the consequences to maturing as
a product focused company is that we have seen a decrease in the level of complexity of
our decision-making. We are no longer trying to decide which of the many different
options for technology we should develop. Instead, we know we need to execute in just a
few key areas: We need to take our advances in LEDs and become the leader in LED
color technology – one of the strongest global markets. We also have to roll out our
successful security products on a major scale. We need to partner with a strong company
in the life science field so that our early product development can progress and return
benefits to the company. This journey of transition is probably not unique to
semiconductor nanocrystal technology and could be translated to carbon nanotube, nanowires, and other multi-purpose materials technologies as they mature.
AB INITIO DESCRIPTION OF THE QUANTUM DOT WITH NOVEL
CORE STRUCTURE AND THEIR INTERACTION WITH ORGANIC
LIGAND
R. V. Belosludov1, H. Mizuseki1, A. Kasuya2 and Y. Kawazoe1, 1Institute for
Materials Research, Sendai 980-8577, Japan; 2Center for Interdisciplinary
Research, Tohoku University, Sendai 980-8578, Japan; [email protected]
167
Fluorescence diagnostics has recently gained an alternative implement in colloidal
semiconductor quantum dots (QDs) due to their bright fluorescence, narrow emission,
broad UV excitation, and high photostability. The aim of this study is to gain an
understanding of the structural morphology of the semiconductor core structure as well as
the inorganic/organic interface at the atomistic level using highly accurate first-principles
calculations in an effort to improve upon the materials currently used in cancer diagnosis
and to provide experimentalists with the necessary data for the actual realization of these
nanomaterials. The common strategy for making QDs biocompatible includes both
covering the semiconductor core structure (CdSe) by a shell of semiconductor material
(ZnS) with a larger band gap followed by a bio cap using different functional molecules
which improve the solubility of the QD and provide a specific target to anticancer agents.
However, even in this case, cyclotoxicity, correlated with the liberation of free Cd2+ ions
due to deterioration of the CdSe lattice, has been observed. The current CdSe-core QDs
have a crystalline structure. Therefore, one solution to the cyclotoxicity problem is to
design and synthesize new nanocomposites that are more stable than crystalline QDs.
Using first-principles calculations, we have predicted the existence of (CdSe)n (n=33 and
34) nanoparticles, which were also identified by mass spectrometry. These nanoparticles
do not adopt the crystal form of CdSe while resembling more closely carbon fullerenes
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and are remarkably stable. Using these configurations as initial structures, the new shellcore particles (ZnS)28/(CdSe)4 are found to be energetically stable. These results indicate
the possibility of the formation of stable shell-core nanoparticles with a small
concentration of Cd, significantly reducing the toxic effect of fluorescence II-VI
semiconductor QDs. We have also found a highly stable nanocluster (CdSe)61 with the
same core/shell feature, allowing us to suggest the possibility of an experimental
synthesis of fullerene-like structures with a diameter of approximately 2 nm. As a
continuation, we investigated the effect of organic ligand binding on the stability of CdSe
as well as CdSe/ZnS nanoparticles with both crystalline and fullerene-like structures.
There are several ligands such as MAA, DTT, DHLA employed in these calculations.
The results show that the interactions of these ligands with crystalline particles are
stronger than with fullerene-like particles due to charge transfer between the organic
ligand and the surface atoms. This leads to a strong distortion of the core surface and in
some cases, to decomposition of the nanoparticle. Moreover, the full covering of QDs can
be easily achieved in the case of nanoparticles in comparison to the crystalline forms. Our
results indicate that decreasing the size of the imaging agent can possibly lead to
biologically inert coverings, making it possible to avoid cellular toxicity.
PHOTOLUMINESCENT RARE-EARTH-BASED LAMELLAR
ORGANIC-INORGANIC NANOPARTICLES
Nicola Pinna, Mohamed Karmaoui, Department of Chemistry and CICECO,
University of Aveiro, 3810-193 Aveiro, Portugal; [email protected]
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The actual requirements for phosphors demands for high emission efficiency and for
lower energy excitation compared to standard materials used in luminescent lamps, flat
screens, television and biological labeling. However, in order to comply with such
requirements new materials are needed. In fact, standard phosphors are based on the
absorption due to a charge transfer mechanism related to the excitation of an electron
from the oxygen 2p orbital to the 4f orbitals of a Eu(III) ion which generally takes place
at around 250 nm (i.e. 5 eV). In order to decrease the required excitation energy materials
based on different absorption physical processes are needed. A good approach is to use
the larger absorption cross sections and low energetic absorptions of organic molecules to
absorb the incident radiation which will be further transferred to the emitting lanthanide
ions (antenna effect). However, lanthanide (Ln) complexes are known to be unstable
under a UV excitation. In the last few years it was shown that non-aqueous sol-gel
reactions of benzyl alcohol with different metal oxides precursors (alkoxides, chlorides,
acetylacetonates,…) allow the controlled and straightforward synthesis of various
crystalline metal oxide nanoparticles. Here, we present a general non-aqueous sol-gel
route for the preparation of rare-earth (RE) ordered nanocrystalline hybrid structures. In a
simple one-pot reaction process, RE(III) isopropoxides (RE= Y, Er, Gd, Sm, Nd) were
dissolved in different alcohols and reacted in an autoclave between 250 and 300°C. This
approach leads to 50 nm nanoparticles made of very thin (~0.6 nm) crystalline rare-earth
oxide layers regularly separated from each other by organic layers of intercalated
carboxylate molecules derived from the oxidation of the alcohol used as solvent (the
thickness of the organic part is typically between 1.2 – 2.0 nm). The optical properties of
107
such hybrid nanoparticles doped with various lanthanides emitting ions were evaluated. It
was found that an efficient charge transfer from the organic moieties to the Ln(III)
emitting ion takes place. By following such an excitation path the energy required in
order to sensitize the luminescent ions is significantly lower than the one needed by
similar pure inorganic compounds. Furthermore, because the absorption cross section of
the intercalated organic molecules is much larger than the one of the charge transfer
mechanism related to the excitation of an electron from the oxygen 2p orbital to the 4f
orbitals of a Ln(III) ion the radiance observed is larger (up to 50%) than the one observed
in standard phosphors used in luminescent lamps, screens, etc. Finally due to the presence
of organic molecules which naturally emit in the blue and green region of the visible
spectrum the emission chromaticity can be tuned by the excitation energy without losing
the high radiance values.
NUCLEATION AND GROWTH OF METALS, OXIDES AND
CHALCOGENIDES IN POLYOLS: CONTROL OF SIZE AND SHAPE OF
THE PARTICLES.
Fernand Fiévet, I.T.O.D.Y.S. Université Paris7-Denis Diderot, UMR CNRS
7086, 2, place Jussieu 75251 Paris Cedex 05 France; [email protected]
169
Over the past years the so-called polyol process has proven to be a valuable route to
prepare nanoparticles of various materials such as noble metals, magnetic metals or
alloys, oxides, chalcogenides…Whatever the chemical reaction involved (reduction,
hydrolysis, …) it is often possible by varying experimental conditions such as reaction
temperature, use of a nucleating agent, basicity of the reaction medium, hydrolysis ratio
to control the nucleation and growth steps of the particles. I will be exemplified how this
process appears as a valuable tool for the synthesis of highly crystalline monodisperse
particles with a very good control of composition, size and shape.
SYNTHESIS, CHARACTERIZATION AND BIO-TEMPLATED
ASSEMBLY OF HIGHLY PHOTOLUMINESCENT WATER SOLUBLE
QUANTUM DOTS
Qing Song, Xin Ai, Qi Xu, Shiyou Ding, Mike Himmel, Garry Rumbles and
Arthur J. Nozik, National Renewable Energy Laboratory, 1617 Cole Blvd.
Golden, CO 80401 [email protected]
170
To make highly photoluminescent water solube quamum dots (QDs) has been becoming
very desirable as QDs are becoming the system of choice for photoluminescent
biolabelling applications, and in many cases usurping, with greater stability, their
molecular counterparts especially in single-species spectroscopies. In this presentation,
we will discuss a detailed synthesis and the photophysics studies of water soluble core
shell structured CdSe@ZnS and InAs@CdSe/ZnSe quantum dots that have been
stabilized with a combination of two amino acids, histidine and N-acetylcysteine (NAC).
We show that this combination readily produces very stable solutions with good PL
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efficiencies in UV-Vis and high PL efficiencies in NIR in the pH 6-8 range. Furhtermore,
these amino acid modified QDs can also be readily assemblied on the cellulose substract
via a histidine-modified, cellulose-bound protein.
NEW APPROACHES TOWARDS WATER-SOLUBLE AND
FLUORESCENT METAL NANOCLUSTERS
Hongwei Duan, Min Kuang and Shuming Nie, Department of Biomedical
Engineering, Emory University and Georgia Institute of Technology, 101
Woodruff Circle, Suite 2007, Atlanta, GA30322, USA; [email protected]
171
Metal and semiconductor nanoparticles are a topic of considerable interest in chemistry,
biology, and materials sciences. This broad and interdisciplinary interest arises not only
from their novel size-dependent electronic and optical properties but also from their
dimensional similarities with biological molecules such as nucleic acids and proteins. For
semiconductors with well-defined energy band gaps, strong quantum-size confinement is
observed when the particle sizes are smaller than the exciton Bohr radius (about 4-5 nm
for CdSe). This has allowed the development of semiconductor quantum dots as a new
class of fluorescent labels with unique properties and applications that are not available
from traditional organic dyes and fluorescent proteins. In contrast, metallic materials such
as silver and gold do not have a discrete band gap, and quantum-mechanical properties
are only observed in atomic clusters that are smaller than the Fermi wavelength (less than
1 nm) of the conduction electrons. As a result, metal nanoclusters consisting of only
several to tens of atoms are likely to behave as “artificial atoms,” showing discrete and
size-tunable electronic transitions. Due to this stringent size requirement, progress has
been slow in developing fluorescent metal particles. This talk will cover our recent
development in new approaches towards water-soluble and highly-fluorescent metal
nanoclusters by using functional group-dense hyperbranched polymers as synthetic
templates.
ENHANCED VISIBLE LIGHT PHOTOCATALYSIS BY TAILORING
DEFECTS IN ZINC OXIDE CRYSTALS
Sunandan Baruaha, Sudarson Sekhar Sinhab, Samir Kumar Palb, Arup Kumar
Raychaudhurib and Joydeep Duttaa; a Center of Excellence in
Nanotechnology, School of Engineering and Technology, Asian Institute of
Technology, Klong Luang, Pathumthani 12120, Thailand; bS.N.Bose National
Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata , 700 098.
India; [email protected]
172
Toxic wastes from industries lead to environmental pollution and a lot of effort is being
put in for the removal of harmful contaminants from soil and waste water. Wide band gap
metal oxide semiconductors like zinc oxide (ZnO) show photocatlytic activities that have
been used to degrade the harmful organic contaminants into harmless mineral acids.
Metal oxides show enhanced photocatalytic activity with the increase in defects in the
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crystals. A commonly used method of incorporating defect sites or electron vacancies
into the ZnO crystal is through doping using transition metals like manganese, iron,
cobalt, etc. However, we have proposed the creation of native crystal defects by
controlling the crystallization phenomena during the growth of ZnO nanoparticles. This
was achieved through fast nucleation and growth of the crystals and subsequent
quenching of the precipitation reaction. The fast nucleation and growth of ZnO
nanoparticles was achieved by the use of microwave irradiation for the hydrothermal
synthesis. ZnO, with a bandgap of 3.37 eV normally absorb electromagnetic waves in the
ultra violet region below 370 nm, but by introducing defects into its crystal lattice we
observe a shift in the optical absorption more towards the visible light band (400nm to
700nm) through the creation of intermediate states that inhibits electron hole
recombination. Photoctalytic degradation of Methylene blue (MB) were studied under
visible light illumination with conventionally hydrolysed and microwave synthesized
ZnO NPs as well as ZnO NPs doped with manganese (ZnO:Mn2+). The photocatalytic
degradation of the dye showed that undoped ZnO nanoparticles synthesized using
microwaves have comparable photocatalytic activities as the transition metal doped
samples using conventional hydrolysis for the nanoparticle synthesis. To elucidate the
change in photocatalytic activity, time correlated single photon spectroscopy was used to
observe the electronic transitions as excited electrons radiate energy to return to their
stable states. The luminescence decay curves exhibited three decay component: (i) a very
fast decay with time period τ1~ 0.5 ns (ii) a medium decay with τ2 ~ 5 ns and (iii) a very
slow decay with τ3~ 44 ns. The percentage population of electrons present in the slow
decay level is higher (~43%) as compared to the conventionally synthesized ones (~26%)
indicating higher defective states in the microwave synthesized NPs, which is also
reflected in the photocatalysis study. In this work we correlate the photocatalysis results
with the lifetime measurements of the charge carriers.
METALLIC NANOPARTICLES SYNTHESIZED UNDER SOFT
REACTION CONDITIONS WITH HIGH YIELDS
Donaji Velasco-Arias1, Maiby Valle-Orta1, David Díaz1*, Patricia SantiagoJacinto2 and Luis Rendón-Vázquez2, 1Facultad de Química, 2Instituto de
Física, Universidad Nacional Autónoma de México, Ciudad Universitaria,
Coyoacán, CP 0410, México D.F., México; [email protected]
173
In this contribution novel, easy and fast synthesis procedures of zero-valent bismuth,
copper and iron nanoparticles will be shown (ZV-M NPs). These reduction reactions take
place in few minutes, in colloid dispersions, using organic polar media, at room
temperature, with high yields. In all cases the reducing agent is NaBH4. Sometimes
additional organic species are used as nanoparticles stabilizers, such as citrate ions or
triethylamine (TEA). Dimethylsulfoxide (DMSO), N, N´-dimethylformamide (DMF) and
ethyleneglycol are the solvents that we used as reaction media. A typical synthesis
procedure of ZV-Bi Nps includes Bi(NO3)3·5H2O (2 x 10-4 M), as metallic source,
Na3(C6H5O7)·2H2O, (2 x 10-4 M) as capping agent, previously solved in few drops of
water, NaBH4 (4 x 10-4 M) solved in 0.5 mL of methanol, and 24.5 mL of DMSO. All
solutions were previously bubbled with argon as well as the final reaction mixture. The
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corresponding chemical reaction is:
9 H2O + 3 [BH4]-1 + 4 Bi+3 ⇒ 6 H2⇑ + 3[BO]-3 + 18 H+1 + 4Bi°
Using this ZV-Bi NPs chemical pathway, the resulting average particles diameter is 3.3 ±
0.97 nm, with a narrow distribution. Similar preparation methods are used for ZV-Fe and
ZV-Cu NPs. The copper particles mean size is smaller than 12 nm. Otherwise, it is
possible to distinguish two ZVI-NPs populations. The smaller NPs are superparamagnetic
and they have an average diameter of ca. 5 nm. The other NPs are larger than 10 nm and
exhibit ferromagnetic behavior. The characterization of the above mentioned ZV-M NPs
includes the determination of the surface electric potential of the suspended particles, XRD, Raman, FT-IR, Mössbauer, UV absorption electronic, EELS, Z-contrast
spectroscopies and HR-TEM.
NANOMATERIALS AND THEIR APPLICATION IN BIOMEDICINE
Michael Giersig, CEASAR Research Center, Ludwig-Erhard-Allee 2,
D-53175 Bonn, Germany; [email protected]
174
The goals of the Nanoparticle Technology Group lie in the preparation of nanometersized semiconductor, metallic, and magnetic particles, followed by the creation of
periodically ordered nanostructures (1-D, 3-D) based on single nanosized materials. An
important factor in this context so far has been the design and fabrication of
nanocomponents with new functionalities and characteristics for the improvement of
existing materials, including biocompatible conductive materials, polymers, and
composites. With this concept of nanotechnology in mind, we aim at developing
innovative products and application options a number of which will be discussed in this
presentation.
FUNCTIONALIZED INORGANIC NANOSTRUCTURES FOR
BIOMEDICAL APPLICATIONS
Bonroy K., Jans H., Van de Broek B., Jans K., Reekmans G., Van Summeren
A.,Van Meerbergen B., Stakenborg T., Trekker J., Bartic C., Verhaegen K.
and Borghs G. IMEC, Kapeldreef 75 Heverlee 3001, Belgium;
[email protected]
175
Nanomaterials differ significantly from other materials due to two principle factors: the
increased surface area and quantumsize effects. These factors can enhance properties
such as reactivity, strength and physical characteristics including optical, electrical and
magnetic behaviour. Due to these characteristics, the coupling of nanomaterials to
biomolecular entities has the potential to revolutionize many fields of science and
technology, possibly having a significant impact on current biomedical technologies,
nanoelectronics and related areas. Our main goal is to synthesize tunable functionalized
nanostructures and to explore their use in applications such as sensing, imaging,
diagnostics, and treatment. To allow a full exploration, these functionalized
nanostructures need to be developed at the crossroads of nanotechnology, chemistry,
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biology and engineering. IMEC, one of Europe's leading independent research center in
the field of micro- and nanoelectronics, nanotechnology, enabling design methods and
technologies, is carrying out controlled interactions of biomolecules with various
nanostructures that might be important for modern bioelectronics and life sciences. This
includes processes using magnetic and metal nanomaterials for biosensing, imaging, cellinteractions and hyperthermia treatment. In this presentation, we will discuss different
synthesis methods to obtain metal and superparamagnetic nanostructures especially
designed for the needs defined by their final application. In addition various
modifications of these nanostructures will be presented to make them more suitable for
integration with biological applications. These modifications will include a
functionalization of the nanostructures with a surface layer for enhanced solubility,
biocompatibility or biorecognition abilities. These different modification steps are
extensively characterized using Transmission Electron Microscopy (TEM), Atomic
Emission Spectroscopy (AES), Fourier Transform Infra-Red Spectroscopy (FTIR), UVVis spectroscopy, Surface Plasmon Resonance (SPR), Confocal Microscopy and
Dynamic Light Scattering (DLS). Performance of the synthesized nanostructures in
various applications such as sensing, heat generation and cell-interaction will be
highlighted. During this presentation the above mentioned activities will be outlined and
first results of this research will be presented.
MICROGEL-BASED INKS FOR PAPER-SUPPORTED BIOSENSING
APPLICATIONS
Shunxing Su, Md. Monsur Ali, Carlos D. M. Filipe, Yingfu Li, Robert
Pelton, McMaster University, Hamilton, Canada; [email protected]
176
As a first step for the development of biosensing inks for inexpensive paper-based
biodetection, we prepared paper stripes printed with carboxylic poly(Nisopropylacrylamide) microgels that were modified either with an antibody or with a
DNA aptamer. We found that the antibody and the DNA aptamer retained their
recognition capabilities when coupled to microgel. The printed microgel remains
stationary during chromatographic elution while the microgel-supported molecular
recognition elements are accessible to their intended targets present in the elution
solution. Our work indicates that microgels, large enough to isolate the biosensors from
the paper surface, are sufficiently hydrophilic to be wetted during chromatographic
elution, exposing the gel-supported affinity probes to their targets.
CALCIUM PHOSPHATE NANOCOLLOIDS FOR BIOIMAGING AND
DRUG DELIVERY
J.H. Adair*, S.M. Rouse, T.T. Morgan, E.I. Altinoglu, T.J. Russin, M.R.
Parette, A. Tabakovic, W.B. White, P.C. Eklund, J.K. Yun, Y. Heakal, A.
Sharma, G.P. Robertson, V. Ruiz-Velasco and M. Kester, Pennsylvania State
University, University Park and Hershey, PA; NSF Ceramic and Composite
Materials Center, 249A MRL Building, Hastings Road, Pennsylvania State
177
112
University, University Park, PA 16802, USA; [email protected]
Paradigm-shifting modalities to more efficiently deliver drugs to cancerous lesions
require the following attributes: nanoscale-size, targetability and stability under
physiological conditions. Often, these nanoscale drug delivery vehicles are limited due to
agglomeration, poor solubility or cytotoxicity. Thus, we have designed a methodology to
encapsulate hydrophobic antineoplastic chemotherapeutics within a 20-30 nm diameter,
pH-responsive, non-agglomerating, non-toxic calcium phosphate matrix. These 20nmsized nanocolloids can encapsulate both fluoroprobes and chemotherapeutics for in vitro
and in vivo delivery to cells. The encapsulated fluoroprobes exhibit enhanced
photostability and fluorescent emission and are colloidally stable in physiological
solution at 37°C. As examples of the general potential for fluoroprobe-encapsulated
calcium phosphate nanoparticles in medical research, we have used them to image a
variety of cells in culture including: acutely isolated sympathetic neurons, vascular
smooth muscle, and cancer cells without significant toxicity over therapeutic ranges.
Furthermore, ceramide, an experimental bioactive, but physiologically insoluble, anticancer lipid was delivered within calcium phosphate nanoparticles to melanoma and
drug-resistant breast adenocarcinoma cells, resulting in significant cytotoxicity and
apoptosis. Our findings indicate that non-toxic calcium phosphate nanoparticles have the
potential to increase the efficacy of physiologically insoluble drugs in vivo as well as to
provide enhanced bioimaging.
NIR ACTIVATED UPCONVERSION NANOPARTICLES WITH VISIBLE
EMISSION FOR SENSING AND IMAGING
G.S. Yi and G.M. Chow, Department of Materials Science and Engineering,
National University of Singapore, Kent Ridge, 119260, Republic of
Singapore; [email protected]
178
Fluorescent materials, as bio-probes and sensors, should be ideally resistant to photobleaching, biocompatible, nontoxic, highly luminescent and highly sensitive, both in vitro
and in vivo. Down-conversion organic dyes, fluorescent proteins and semiconductor
quantum dots face the challenges of background signal due to autofluorescence and
interference from biomolecules that can also be excited by the UV radiation. An
upconversion multi-photon fluorescent bio-probe absorbs two or more low energy nearinfrared (NIR) photons to emit a higher energy visible photon. The key advantages of
upconversion probes include improved signal-to-noise ratio, increased tissue penetration,
and reduced photo-bleaching and decreased photo-toxicity. The multi-photon
upconversion probes are mainly fluorescent organic dyes and fluorescent proteins. Their
extremely low two-photon fluorescence efficiency requires excitation power density in
the order of 106-109 W.cm-2 that can be delivered by an expensive, femto-second pulse
titanium-sapphire NIR laser. The infrared-to-visible upconversion phosphors, with
nanoscale size range and narrow size distribution, high quantum yield and fluorescence
efficiency and “water soluble”, may be excited using inexpensive small laser diode or
NIR lamp. In this talk, we present our work on the chemical synthesis of NIR-to-visible
upconversion fluorescent nanocrystals of Yb–Er, Yb–Ho and Yb–Tm co-doped LaF3; and
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Yb–Er and Yb–Tm co-doped NaYF4 (core, core/shell and PAA coated core/shell). The
effects of microstructure and crystal structure on the visible light (green, red and blue)
emission properties were investigated. The dispersion of these nanoparticles in both
polar and aqueous solvents was studied. The application of these nanocrystals in bioimaging was also pursued.
INFLUENCE OF GOLD NANOPARTICLES ON THE ATTACHMENT OF
OSTEOBLAST CELLS TO SUBSTRATES
Silvia H. De Paoli Lacerda, Nancy J. Lin, Matthew Becker, Jack F. Douglas,
Alamgir Karim. Polymers Division, National Institute of Standards and
Technology, Gaithersburg, Maryland 20899, USA; [email protected]
179
The adhesion of cells to each other and to substrates is crucial in the development of
healthy tissue, the inhibition of tumor growth and metastasis, and the suppression of
immune response in auto-immune diseases. Cell attachment to surfaces is mediated by a
large group of proteins that can be subdivided into families (integrins, cadherins, selectins
and immunoglobulins) based on their chemical structure or biological function. Proteins
are a type of naturally occurring nanoparticle, and we hypothesize that synthetic
inorganic nanoparticles can similarly affect cell adhesion. We investigate this hypothesis
by comparing cells seeded on substrates both with and without prior exposure to model
gold nanoparticles. We choose gold nanoparticles and protein-coated gold nanoparticles
for our initial study since these particles are relatively biocompatible, and efficient at
scattering and adsorbing radiation for both diagnostic and therapeutic studies. These
particles can also be obtained in a reasonably monodisperse form for a range of particle
sizes, and the surface chemistry is tunable through the attachment of a wide variety of
grafted proteins and other polymer layers. Our initial results indicate that the attachment
and morphology of MC3T3-E1 murine preosteoblast cells are indeed affected by
spherical gold and histone-coated gold nanoparticles having a range of diameters: 5 nm,
30 nm and 60 nm. Fluorescence and electron microscopy measurements show that the
nanoparticles are physically aggregated on the cell membrane, a process that probably
affects cell uptake. We conclude that while nanoparticles offer potential in cancer therapy
and diagnostic applications and in the treatment of other diseases relating to cell
attachment, their strong biological activity also points to possible unintended
consequences of these particles to normal biological function through nanoparticle
exposure in the environment.
SIMULTANEOUS IMAGING AND DELIVERY OF SIRNA WITH
QUANTUM DOTS
Xiaohu Gao, Department of Bioengineering, University of Washington,
William H. Foege Building N530M, Box 355061, Seattle, WA 98195-5061,
180
The rational design of multifunctional nanoparticles for siRNA delivery and imaging
based on the use of semiconductor quantum dots (QDs) and proton-absorbing polymeric
coatings is discussed. With a balanced composition of amine and carboxylic acid groups,
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these nanoparticles are designed to address barriers in siRNA delivery such as cellular
penetration, endosomal release, carrier unpacking, and intracellular transport. The results
demonstrate dramatic improvement in gene silencing efficiency and reduction in cellular
toxicity, when compared directly with existing transfection agents. The QD-siRNA
nanoparticles are also dual-modality optical and electron-microscopy probes, allowing
real-time tracking and ultrastructural localization of QDs during delivery and
transfection. These new insights and capabilities represent a major step towards
nanoparticle engineering for imaging and therapeutic applications.
GOLD NANOPARTICLE PROBE-BASED IMMUNOASSAY FOR
CANCER BIOMARKER DETECTION
Xiong Liu, Qiu Dai, Lauren Austin, Janelle Coutts, Qun Huo, Nanoscience
Technology Center, Department of Chemistry, Department of Mechanical,
Materials and Aerospace Engineering, University of Central Florida, 12424
Research Parkway Suite 400, Orlando, FL 32826, USA; [email protected]
181
Gold nanoparticles, including spherical particles, nanorods and nanoshells with a size
ranging from 10s to 100s nanometers, are known to have a large light absorption and
scattering cross section in the surface plasmon resonance wavelength region. The
magnitude of light scattering by a gold nanoparticle can be orders of magnitude higher
than light emission from strongly fluorescing dyes. This unique property has enabled
many important and promising applications of metal nanoparticles in biomedical field,
such as molecular and cell imaging, biosensing, bioassays, and photothermal therapy.
Recently, we developed a one-step homogeneous immunoassay for the detection of a
prostate cancer biomarker, free-PSA (Prostate Specific Antigen), using gold nanoparticle
probes coupled with dynamic light scattering (DLS) measurements. A spherical gold
nanoparticle (GNP) with a core diameter around 37 nm and a gold nanorod (GNR) with a
dimension of 40 by 10 nm were first conjugated with two different primary anti-PSA
antibodies and then used as optical probes for the immunoassay. In the presence of
antigen f-PSA in solution, the nanoparticles and nanorods aggregate together into pairs
and oligomers through the formation of a sandwich type antibody-antigen-antibody
linkage. The relative ratio of nanoparticle-nanorod pairs and oligomers versus individual
nanoparticles was quantitatively monitored by DLS measurement. A correlation can be
established between this relative ratio and the amount of antigen in solution. The light
scattering intensity of nanoparticles and nanoparticle oligomers is several orders of
magnitude higher than proteins and other typical molecules, making it possible to detect
nanoparticle probes in the low picomolar (pM) concentration range. f-PSA in the
concentration range from 0.1 to 10 ng/mL was detected by this one-step and washing-free
homogeneous immunoassay. As opposed to the traditional plate-based immunoassay, our
assay is conducted in solution, which allows a much better mixing and antibody-antigen
interaction. The assay does not involve any washing cycle and the assay result can be
read as soon as the nanoprobe-sample incubation is completed. Moreover, extremely
small amount of samples are needed for the assay (in this study, about 3.3 μL sample
solution was used for each assay). The same concept has also been applied successfully
for quantitative detection and measurement of DNA targets.
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ENCAPSULATION OF MOLECULES IN MESOPOROUS SILICA
PARTICLES: PRINCIPLES AND APPLICATIONS
Igor Sokolov, NABLAB and Dept. of Physics, Clarkson University,
Potsdam, NY13699, USA; [email protected]
182
Various molecules can be confined inside silica nano(meso)channels during selfassembly of porous silica shapes/particles synthesized in so-called method of templated
sol-gel assembly. Combining different molecules, in principle, one could build a
microscopic device/particle with complex response to external stimuli. I will demonstrate
this idea for an example of fluorescent dyes confined inside nanosize channels of micronsize silica particles. From geometrical point of view, the synthesized silica particles are
well aligned arrays of parallel nanochannels. Diameter of nanotubes can be tuned during
synthesis from ~2 to 10 nm. Aligning different molecules inside each tube in a one
dimensional array, one can attain various nontrivial properties. I will demonstrate
ulrabright fluorescent silica particles that are ~170-260 times brighter that similar size
colloidal agglomeration of quantum dots. Using different dyes we built particles in which
the dye molecules are sufficiently close to each other to work in the regime of nonradiative energy transfer. This may bring a new family of novel sensors. Temperaturesensing particles based on this principle will be demonstrated.
TEMPLATED FABRICATION OF HOLLOW GOLD NANO-GRENADE
PARTICLES FOR CONTROLLED DRUG DELIVERY
Nicholas C. Linn and Peng Jiang, Department of Chemical Engineering,
University of Florida, Gainesville, FL 32611, USA; [email protected]
183
Hollow particles play an important role in microencapsulation – a process that has been
widely exploited for controlled release of drugs. Here we report the fabrication of hollow
gold nano-grenade particles by a simple templating process. Non-close-packed colloidal
monolayers prepared by a simple spin-coating process are used as templates. A thin film
of gold can be sputtered or electrolessly plated on the surface of the particles and the
silica templates can be removed later on to form grenade-shape hollow nanoparticles. The
resulting particles exhibit tunable plasmonic properties which can be easily tuned by
changing the template particle size and the shell thickness. The optical properties of the
two-dimensional (2D) ordered hollow particles have also been investigated by both
experiments and theoretical calculation using a rigorous coupled-wave analysis (RCWA)
model. The interior of the hollow nanoshells can be filled up with chemicals and the
opening can then be sealed by a thin layer of hydrogel. We show that the chemicals
inside the nanoshells can be delivered in a controlled manner when a laser is illuminated
on these composite particles.
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BIOPOLYMERIC MICROPARTICLES FOR ENCAPSULATION OF LIVE
CELLS: BIOTRANSPORT AND BIOCOMPATIBILITY CONSIDERATIONS
Anil K. Anal, Paul J. Tan, Robert B. Elliott, Maria Muzina, Michelle Tatnell,
Livia Escobar, Bri E.Bintz, Christopher G.Thanos; Living Cell Technologies
(Global) Ltd., Auckland 2025, New Zealand; [email protected]
184
Microencapsulation of cells and cell aggregates has been the most widely explored
immunisolation strategy, but widespread clinical application of this technology has been
limited, in part, by inadequate transport of nutrients, deleterious inflammatory responses, and
immune recognition of encapsulated cells via antigen presenting pathways. For
immunoprotection of these live cells, the polymeric membrane should allow permeability of
glucose, insulin, oxygen and other metabolically active products, to ensure the functionality
and therapeutic effectiveness of those cells. However, it must also prevent the passage of
cytotoxic cells, macrophages, antibodies, and complement to remain effective.
The successful immunoprotection requires the membranes that not only provide protection
of the encapsulated cells from the host immune system, but also have properties that
diminish the release of xenogenic antigens (typically < 20 nm) through reduced pore size and
surface properties that prevent nonspecific adsorption. Alginate-polycation nanoporous
biocapsules with permselective membranes of nanoscale thickness is achieved by applying
layer-by-layer (LbL) fabrication technique. These enhanced biocapsules have been
characterized and implanted into the brain, peritoneal cavity and subcutaneous space in
model animals. The transport properties of enhanced nanoporous biocapsules were
characterized by the values of the diffusion coefficient (permeability), molecular mass-cut
off, solute ingress or egress percentage. The determination of the solute mass diffused into
capsule, and the exodiffusion can provide an accurate estimate of the behavior in an
application, such as the metabolite supply to encapsulated cells or release of bioactive
compounds. The pore size is reduced down to 10s of nm, coupled with modification of the
outer biocapsule wall to prevent protein binding, nonspecific adsorption and would be able
to overcome the immunological challenges and hinder the passage of small cytokines and the
release of xenogenic antigens. The surface properties, layer deposition and pore size of
enhanced alginate biocapsules (pre- and post-implantation) were observed under electron
and confocal microscopy. The three dimensional surface profiles and molecular interactions
of the layers were observed by atomic force microscopy (AFM). Fourier-transformed
infrared spectroscopy (FTIR) analysis and surface morphology from microscopy indicated
that the enhanced alginate-polycation biocapsules has the capability of survival in all sites,
including the harsh peritoneal environment, for at least 215 days.
ELECTROSPRAY IN THE DRIPPING MODE FOR CELL
MICROENCAPSULATION
Jingwei Xie and Chi-Hwa Wang, Department of Chemical and Biomolecular
Engineering, National University of Singapore, 4 Engineering Drive 4,
Singapore 117576; [email protected]
185
Entrapment of living cells in microbeads is to protect the encapsulated cells from the
host’s immune system, which can be used as drug delivery vehicles, immunotherapies
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and engineered tissues. The main objective of the present study was to investigate the
droplet formation and to better develop mono-dispersed microencapsulation of living
cells with controllable size. The uniformity of microencapsulation size was realized by
performing electrospray in the dripping mode and also stabilized by an additional ring
electrode. Reduction of droplet diameter and increase in the dripping frequency were
observed with increasing applied voltage to the nozzle using a conventional electrospray
setup. The vibration of the needle was found to reduce when high voltage was applied to
the nozzle. With increasing voltage applied to the rin modified ele g electrode, the
dripping frequency was found to decrease with the formation of slightly larger sizes of
droplets. Hep G2 cell line was taken as the model cell line for encapsulation in calcium
alginate microbeads. Relatively uniform microbeads could be achieved when operating
under low flow rates with high voltages applied to the nozzle by using a conventional
electrospray setup. In contrast, uniform microbeads can not be obtained using a similar
setup under high flow rates unless the ring electrode is applied with voltage to stabilize
the electrospray in the dripping mode. In this ctrospray, microbeads with narrow size
distribution and slightly larger size can be obtained even for cases under high flow rates.
Phase contrast microscope images showed that the diameter of microbeads from around
200 µm to 2 mm could be finely tuned by adjusting various operating parameters.
TRANSLATING THERAPEUTIC NANOPARTICLES
Cory Berkland1,2; 1Department of Chemical and Petroleum Engineering,
University of Kansas; 2Department of Pharmaceutical Chemistry, University
of Kansas, 2030 Becker Drive, Lawrence, KS 66044, USA; [email protected]
186
Pharmaceutical formulations containing nanoparticle colloids have emerged in the clinic.
As a prime example, nanoparticle suspensions consisting of drug particulates have lead
the way by improving the performance of poorly water soluble drugs. In contrast,
nanoparticles designed to carry and deliver potent therapeutics in a targeted fashion have
not yet matured to the point of tangible products. A wave of research aims to remedy this
disconnect by improving the function of nanoparticulate drug delivery vehicles. Our lab
has been working in each of these areas to develop nanoparticle formulations that
effectively deliver, stabilize, target, and/or sustain the therapeutic effects of active
pharmaceutical ingredients. A new approach for formulating dry powder aerosols using
drug nanoparticles as building blocks will be discussed. Also, our efforts for improving
the performance of injectable nanoparticles will be presented. Specifically, data will
illustrate nanoparticle tracking using MRI, nanoparticle targeting using peptides, and pH
responsive nanoparticles aimed at sub-cellular drug delivery. Each of these efforts will
be highlighted with respect to current trends that are aimed to translate therapeutic
nanoparticle to the market.
FORMATION AND CHARACTERIZATION OF P(NIPAM)/PS
CORE/SHELL POLYMER PARTICLES
Li Zhang, Victoria L. Dimonie, Andrew Klein, and Eric S. Daniels, Emulsion
187
118
Polymers Institute and Chemical Engineering Department, Lehigh University,
111 Research Drive, Bethlehem, PA 18015, USA; [email protected]
Poly(N-isopropyl acrylamide) (PNIPAM), well-known as a thermosensitive polymer with
a lower critical solution temperature (LCST), can reversibly switch from a fully soluble,
hydrophilic random coil at a temperature lower than its LCST to an insoluble globule at a
temperature higher than its LCST. By encapsulating PNIPAM core particles with a
polystyrene (PS) layer to form core/shell structured particles, possible applications can be
envisaged in biological and drug delivery systems, coatings, and micro-reactors. The
objectives of this research are to determine the methodologies needed to synthesize these
particles, to understand the core/shell formation mechanism, and to apply this
methodology to the preparation of other types of core/shell structured particles.
Crosslinked, monodisperse PNIPAM particles were first synthesized by precipitation
polymerization. The particle size of the particles was measured by three techniques under
differing conditions and was found to be 300 nm at room temperature by dynamic light
scattering (DLS), 150 nm at 35 °C by capillary hydrodynamic fractionation (CHDF), and
140 nm in the dry state by transmission electron microscopy (TEM). The particles had a
volume phase transition temperature (VPTT) of 34.9 °C and a glass transition
temperature (Tg) of 154.4 °C. Two different polymerization methods were used to
prepare PNIPAM/PS core/shell particles: a multi-stage process and a semi-batch process.
In both processes, uniform “raspberry” structures were obtained in which polystyrene
formed small domains on the surface of the PNIPAM particles. The resulting particles
were characterized by DLS, CHDF, TEM, and density gradient column experiments. It
was found that the resulting particle size did not change as a function of temperature,
which indicated that the PNIPAM particles were encapsulated by the PS. To smooth the
surfaces of these “raspberry” structured particles, solvent swelling and heat treatment
post-processes were investigated. The heat treatment post-process produced smooth
surfaces while maintaining PNIPAM in the core of the particles. The mechanism of
formation of the “raspberry” structure was investigated. It was found that polystyrene
particles were first formed in the aqueous phase and then heteroflocculated on the
PNIPAM particles. Linear PNIPAM generated in situ may function as a stabilizer for the
PS particles during this process. The PS domains were found to be strongly attached to
the PNIPAM particles. This mechanism can be potentially used for preparing other types
of core/shell particles, particularly those with a hydrophilic core and hydrophobic shell.
PARTICLES WITH COMPLEX SHAPES
Samir Mitragotri and Julie Champion , Department of Chemical
Engineering, University of California, Santa Barbara, CA 93106, USA;
[email protected]
188
Polymeric micro- and nanoparticles are routinely used for applications in drug delivery.
Encapsulation of drugs in polymeric carriers protects them from enzymatic degradation
and provides sustained release over prolonged periods. Further, encapsulation also allows
drug targeting via cell and tissue-specific ligands. The performance characteristics of
polymeric particles in the body, for example circulation times, macrophage clearance,
119
targeting and drug release rates, depend on several particle parameters including size,
shape, surface chemistry, and mechanical strength. Our research aims at developing
quantitative laws describing the relationships between particle design and performance.
We particularly focus on engineering particle shape, a design parameter that has received
little attention in the past. We have devised methods to generate particles of several
distinct shapes and studied their impact on key processes in drug delivery, in particular
phagocytosis, the clearance of particles by macrophages. Our results show that particle
shape makes a profound impact on phagocytosis, more so that particle size. Based on this
understanding, we have designed novel polymeric particles possessing complex shapes
that are highly resistant to phagocytosis. These studies reveal that particle shape provides
a new dimension in engineering of polymeric carriers and opens up new opportunities in
drug delivery.
Session C2 – Keynote Paper
MOLECULAR RECOGNITION BASED PERMANENT ASSEMBLY OF
NON-FCC COLLOIDAL CRYSTALS
Margaret H. S. Shyr, Pierre Wiltzius, and Paul V. Braun, Department of
Materials Science and Engineering, University of Illinois at UrbanaChampaign, Urbana, IL 61801, USA [email protected]
189
Recently, we have discovered that by coupling the power of colloidal self-assembly to
form large area, low defect density colloidal crystals, with the molecular recognition
power and biochemical activity of DNA, that large area, highly stable, non-FCC colloidal
crystals can be formed, and applied for photonic and other applications. The approach is
quite general, and may enable the formation of a diverse array of structures from colloids,
nanoparticles, and molecular objects which are far from the equilibrium self-assembled
structure. Colloidal self assembly has been proposed for over 10 years now as a pathway
to powerful photonic structures, however, to date, almost all structures are of one
crystallography, namely face-centered cubic (FCC), and have rather limited optical
properties. Clearly, if colloidal self-assembly is to make an impact on photonics, a new
paradigm in colloidal assembly will need to be realized. A very significant issue is that
FCC is not the ideal structure for most photonics applications, but through conventional
self-assembly, closed-packed structures almost always are formed. DNA has been
proposed to direct the assembly of colloids into non-FCC structures, however
experimentally, the results have not been entirely satisfying, in part because the
assembled structures are rather unstable, limiting their application. Our approach should
solve most of these problems.
PROTEIN-GUIDED 3D -ASSEMBLIES OF MAGNETIC
NANOPARTCILES
Oksana Kasyutich, Walther Schwarzacher, University of Bristol, H.H. Wills
Physics Lab., Tyndall Av., Bristol BS8 1TL, UK;
[email protected]
190
We report a successful demonstration of application of protein crystallization technique
to prepare a three dimensionally ordered array of magnetic nanocrystals. This method is a
breakthrough in nanofabrication, which allows us to produce a new type of metamaterials
120
with unique magnetic properties. We utilise protein ferritin cages for a template
constrained growth of superparamagnetic nanoparticles of magnetite/maghemite Fe3O4-γFe2O3 (Magnetoferritin), followed by thorough nanoparticles bioprocessing and
purification, and finally by protein crystallization. Protein crystallization is driven by
natural response of proteins to the supersaturation of the electrolyte, which leads to
spontaneous nucleation and 3D-crystal growth. Within short period of time (hours to
days) we were able to grow functional crystals on the mesa scale, with sizes in the order
of tens, up to hundred microns. This is the first of its kind demonstration, as an
alternative to reported earlier colloidal and supra-crystals.
ACOUSTICALLY-INDUCED MICROPARTICLE ORBITING AND
CLUSTERING ON A SOLID SURFACE: ORIGIN AND IMPLICATIONS
Amr I. Abdel-Fattah, Peter M. Roberts, Sowmitri Tarimala, Reem Ibrahim
Los Alamos National Laboratory, Los Alamos, NM 87545, USA;
[email protected]
191
Behavior of colloidal particles in the bulk solution or at interfaces under the effect of
high-frequency acoustics is critical to many seemingly different applications ranging
from enhanced oil recovery to improved mixing in microfluidic channels and from
accelerated contaminant extractions to surface cleaning, drug delivery and
microelectronics. It can be detrimental or beneficial, depending on the application. In
medical research, flow cytometry and microfluidics, for example, acoustically induced
clustering of tracer particles and/or their sticking to the walls of channels, vessels, or
tubes often becomes a problem. On the other hand, it can be tailored to enhance processes
such as mixing in microfluidic devices, particle separation and sizing, and power
generation microdevices. To better understand the underlying mechanisms, microscopic
visualization experiments were performed in which polystyrene fluorescent (468/508 nm
wavelength) microspheres with a mean diameter of 2.26-µm and density of 1.05 g/cm3,
were suspended in either de-ionized water or a 0.1M NaCl solution. The freshly-prepared
colloidal suspension was injected into a parallel-plate glass flow cell, which was
subjected to high-frequency acoustics (200-500 kHz) through a piezoelectric transducer
attached to one of the cell’s outer walls. When the suspending medium is de-ionized
water, acoustic stimulation of the cell at 313 kHz induced three distinct particle
behaviors: 1) entrainment and bulk transport via wavelength-scale Rayleigh streaming, 2)
transport via direct radiation forces to concentrate at nodal or anti-nodal planes, and 3)
entrapment via boundary layer vorticular microstreaming resulting in mobile particles
orbiting deposited particles. This latter phenomenon is intriguing. It occurs at specific
frequencies and the shape of the orbits is determined by the applied frequency, whereas
the rotation speed is proportional to the applied amplitude. At the higher ionic strength,
on the other hand, an additional behavior was observed: chain-like clustering at the cell’s
surface starting with a deposited particle as the “seed” for this chain, which rows in the
opposite direction of streaming. This behavior indicates that micro-scale acoustic effects
are strongly coupled with electrokinetic effects. The different types of particle behavior
observed in our experiments represent important physical mechanisms whereby acoustic
energy is capable of affecting colloid mobility and distribution in systems of various
121
scales. Plausible explanations to these observations include: 1) oscillating pressure
gradient across the deposited particles, 2) recalculating eddies around the deposited
particles, 3) electrokinetic phenomena arising from the relative motion between the
particles and the surrounding fluid, and 4) a phenomenon similar to dielectrophoresis, but
arising from the non-uniform acoustic field in the colloid suspension: Diacoustophoresis.
CRYSTALLINE COLLOIDAL ARRAYS: APPLICATIONS FROM
FILTERS TO LASERS
Stephen H. Foulger, School of Materials Science and Engineering, Center
for Optical Materials Science and Engineering Technologies (COMSET),
Advanced Materials Research Laboratories, 91 Technology Drive, Anderson,
SC 29625, USA; [email protected]
192
The research we are performing at Clemson University is grounded in the fundamental
aspects of crystalline colloidal array derived photonic bandgap (PBG) materials and the
extension of photonic crystal research into functional polymeric composites. Since the
original proposal that three-dimensional periodic dielectric structures could exhibit a
photonic bandgap, considerable attention has been focused on developing these materials
into a form that is suitable for use in photonic applications. Unfortunately, the general
exploitation of visible photonic crystals as devices has been hindered by the challenges in
creating 3D periodic dielectric structures with a feature size comparable to the
wavelength of visible light, as well as achieving significant dielectric contrasts that result
in a strongly scattering system. To surmount these challenges, current effort is being
directed at systems which undergo self-assembly at a nanometer length scale, such as
colloidal crystals. Our group has focused on electrostatically-stabilized crystalline
colloidal arrays. A crystalline colloidal array is a three dimensionally ordered lattice of
self-assembled monodisperse colloidal particles, most commonly amorphous silica or a
polymer latex, dispersed in aqueous or non-aqueous media. At high particle
concentrations, long-range electrostatic interactions between particles result in a
significant inter-particle repulsion which yields the adoption of a minimum energy
colloidal crystal structure with either bcc or fcc symmetry. The ordering of the particles
in the media results in spatial periodicities that range from ca. 100-1000 nm, often
resulting in optical bandgap effects. The three main research thrusts within my group on
these systems include (1) particle synthesis; (2) self-assembly & collective properties;
and (3) device development. These three thrusts will be the major themes of my talk and
will be presented in detail.
PHOTONIC GLASSES AS MATRICES FOR RANDOM LASERS
Cefe López, Instituto de Ciencia de Materiales de Madrid, Calle Sor Juana
Inés de la Cruz 3, 28049 Madrid, Spain; [email protected]
193
Self assembly, the bottom up technique to fabricate complex materials architectures, has
revealed as a powerful means for the fabrication of photonic crystals. This made artificial
opals a playground to test numerous optical properties of photonic crystals both linear
122
and non linear and also to create various applications. Infiltration of opals with guest
materials, a technique known as templating, is an excellent tool to provide additional
functionality to bare opals to enhance their photonic properties. The most commonly used
techniques involve chemical synthesis in the interior of the pores of the opals. They can
be combined to produce several morphologies -conformal growth standing out for its
quality- of different materials and can also be combined with physical ones where the
guest material is introduced rather than synthesized in situ. The principal characteristic of
PBG materials is their periodicity from which all their optical properties stem. When the
order inherent to photonic crystals is eliminated a new category of photonic materials can
be conceived that may, in analogy, be dubbed photonic glasses. In this new scenario,
where diffusion substitutes wave propagation, new phenomena can be expected like
random lasing, localization etc. Strict monodispersity and sphericity of the colloidal
particles results in a resonant behaviour that shows up in the relevant light trandport
magnitudes like mean free path and velocity. The special care needed to produce high
quality photonic crystals is, surprisingly, also needed to produce photonic glasses
because, upon sedimentation, certain colloidal particles show a strong tendency to order
which has to be broken. Only conscientious attempts to fully remove order lead to
structures fully devoid of any remnants of order as evidenced by optical properties or
microscopy. With this material it is possible to create random lasers in which the lasing
wavelength can be decoupled from gain profile and selcted at will.
FABRICATION OF ORDERED 2D ARRAYS OF NANOPARTCLES
USING SELF-ASSEMBLED DIBLOCK COPOLYMER TEMPLATES
Shigeru Watanabe1, Inamur R. Laskar1, Tomokazu Iyoda2
1
Depart. of Appl. Sci., Fac. of Sci., Kochi University, 2-5-1, Akebono-cho,
Kochi 780-8520, Japan 2Chem. Res. Lab., Tokyo Inst. of Tech., 4259,
Nagatsuda, Midori-ku, Yokohama, Kanagawa 226-8503, Japan;
[email protected]
194
Block copolymers to spontaneously form a rich variety of nanoscale periodic patterns
have been received much attention as a self-assembled template on the ‘bottom-up’
nanofabrication, due to the convenient size, shape, and spacing tunability of the wellordered microdomains provided by specifying the volume fraction of each block.
Amphiphilic diblock copolymers PEOm-b-PMA(Az)n consisting of hydrophilic
polyethylene oxide (PEO) and hydrophobic polymethacrylate with azobenzene-based
liquid crystalline side-chains (PMA(Az)), which readily self-assemble into hexagonally
packed PEO cylinders in a PMA(Az) matrix. On the surface of the microphase separated
films, the PEO domains with a nanoscale periodic pattern are chemically distinctive from
the PMA(Az) matrix and are addressable by nanoparticles with high selectivity. In this
paper, we demonstrate the template directed self-assembly of gold nanoparticles followed
by a VUV/O3 etching. The assembled gold nanoparticles are transferred to the underlying
substrate without destroying the regularity of the assembled nanoparticles. The mean
center-to-center distances between the transferred gold nanodots correlated well with the
PEO cylinder period of the PEOm-b-PMA(Az)n used as the templates.
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LIGHT DIFFRACTION ON POLYMER PARTICLE ARRAYS IN THE
OPTICAL FAR- AND NEAR-FIELD
Eckhard Goernitz, Bernd-Reiner Paulke and Juergen Wagner,
Fraunhofer Institute for Applied Polymer Research, Geiselbergstr. 69,
D-14476 Potsdam-Golm, Germany; [email protected]
195
Polymer particle arrays act as 3D optical phase gratings whose lattice constants depend
only on the size (or distance) of the particles. For the fabrication of arrays with grating
functions in the optical transmission range, spherical micrometer-sized polystyrene
particles of very uniform size were prepared by various techniques of emulsion or
dispersion polymerization and the surface functionality of the particles was adjusted in
order to achieve a high organization potential via self-assembly. Mono- and multi-layers
of hexagonally close packed particles were prepared on glass substrates by vertical
deposition and lifting techniques. For some investigations, by filling the voids between
the particles with UV-curable polymers, the refractive index contrast of the arrays was
matched to Δn ≈ 0.03 in order to meet the conditions of kinematic diffraction theory.
The optical transfer functions of these arrays were characterized by means of their
spectroscopic and diffractive properties in the optical far field (Fraunhofer diffraction) as
well as in the near field (Talbot interferences).
Far-field diffraction was investigated by optical microscopy with Bertrand lens on single
crystalline domains as well as by angle dependent laser diffraction and spectral
goniometry. The work focused on the influence of the third lattice parameter (z-direction)
on the spatial and spectral (RGB) intensity distribution of diffracted light and the results
will be discussed with respect to the stacking of hexagonally close packed particle planes
in the array.
Light distribution at distances in the order of several lattice constants behind the array
(optical near field) is of special interest for potential sensor applications based on direct
coupling between the grating and a CCD matrix (Talbot illumination). By means of a
simple microscopic technique, using parallel white light illumination and a motorized
micro-stage, we observed and classified the Talbot pattern behind hexagonally close
packed particle mono-layers (particle diameters in the range between d = 1.4 µm and 8.5
µm). Monochromatically colored Talbot self imaging planes were observed at distances
ZT = 3d2/2λ and polychromatic fractional Talbot planes were found at specific distances
ZT·p/q (with p, q – coprime integers). Fractional Talbot sub-images maintain the
hexagonal order and fit in the original particle arrangement according to the scaling
parameter q. We thank the German Federal Ministry for Education and Research for
financial support.
Session D2 – Keynote Paper
PARTICLE ANALYSIS USING A MULTIWAVELENGTH DETECTOR
ON THE ANALYTICAL ULTRACENTRIFUGE
Engin Karabudak, Saroj Bhattacharyya, Holger Strauss and Helmut Cölfen,
Max-Planck-Institute of Colloids and Interfaces, Colloid Chemistry, Am
Mühlenberg, Research Campus Golm, D-14424 Potsdam, Germany;
196
124
[email protected]
Analytical Ultracentrifugation (AUC) is a classical and powerful technique for the
absolute determination of particle size distributions as it is able to fractionate even very
complex mixtures over the entire colloidal range into the individual components based on
particle size and density. However, up to now, a limitation of the technique was the
availability of detectors besides the standard UV/Vis and refractive index (RI) detectors
of the commercial instrument. Also, the detection speed was not always sufficient to
allow for a high speed and high quality particle size distribution analysis. In this
contribution, we will present the development and application of a fast UV/Vis detector
for the AUC, which is able to simultaneously detect all wavelengths from a larger range.
This greatly enhances the data space from two to three dimensions, allows for averaging
but most importantly allows to determine the UV/Vis spectral properties simultaneously
to the particle size distribution. Also it acts as a turbidity detector with multiple
wavelength dependent sensitivities. The latter allows for the determination of particle size
distribuions with equal detector sensitivity over the entire colloidal range, whereas the
former is important for all particles, which have size dependent optical properties like
small metal or semiconductor colloids. Examples will be presented, which show the
advantages of this detector, namely speed and simultaneous detection of whole UV/Vis
spectra. For example, sedimentation velocity experiments can now be as fast as 150 s
resolving a multicomponent mixture. Also, turbidity detection with multiple sensitivity
will be demonstrated. Spectral properties of quantum size particles and their dependence
on particle size now become accessible in a single sedimentation velocity experiment and
mixtures with multiple chromophores can be resolved in a three dimensional space of
radius, wavelength and absorbance. This opens up possibilities for fast AUC experiments
for particle characterizations revealing additional informations, which were previously
not available and which can hardly be obtained by other techniques with similar
efficiency. This greatly enhances the application range of AUC for particle analysis.
MECHANICAL CHARACTERISATION OF MICRO-METER SIZED
MONODISPERSE POLYMER PARTICLES
Helge Kristiansen and Keith Redford, Zhiliang. Zhang1, Jianying. He1
Conpart AS, Lahaugmoveien 1, 2013 Skjetten, Norway; 1 NTNU, Trondheim,
Norway; [email protected]
197
Polymer particles in the size range of 1-20 micrometers are used for different purposes
within microelectronics and micro-systems. Conpart AS is a Norwegian company
specializing in the manufacturing, characterization and application of such polymer
particles with an emphasis on providing unique properties for use in these applications.
One of the unique properties of these particles is an extremely narrow size distribution.
This is combined with a vide variety of possible chemical compositions, including highly
porous particles or “polymer-matrix” particles filled with different oxides or metals. Also
the surface properties are highly uniform both particle to particle and batch to batch
which makes it easy to provide different types of surface coatings, including metal
plating. Consequently it possible to manufacture particles with a large range of different
mechanical, electrical, optical and other properties. Two of the most demanding
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applications for such particles are as spacers for flat panel displays and as conductive
particles for anisotropic conductive film (ACF). For use in ACF, the polymer particles
are plated with metal to provide electrical conductivity. One of the most critical
characteristics for the particles in both of these applications is the mechanical properties.
Polymer particles have been characterized mechanically by using a modified nanoindenter. A flat “punch” has replaced the traditional pointed indenter tip. Typically a load
curve with linearly increasing load until a maximum value, followed by a short hold and
subsequent de-loading has been used. Major work has been undertaken to obtain a very
high degree of reproducibility and consistency in the results. Important factors have been
mechanical compliance of the substrate on which the particle are placed and wetting
between the fluid in which the particles are dispersed and the substrate prior to the drying
of the particles. This latter has shown to have a significant influence on the adhesion
between particle and substrate. A range of particles with different chemistries including
styrene, acrylates and formaldehyde based and with diameters ranging from 2 to more
than 20 micrometers has been tested. The results show particles with highly different
mechanical properties. Some particles show a typical brittle fracture at a certain load,
depending on the composition of the particle. A FEM analysis has been made using linear
elastic material models. After a very initial period of higher stiffness, some particles seem
to follow an elastic material model for deformations until something like 20%. These
same particles show at the same time a relatively high recovery. Other particle shows a
very different behavior, with no distinct fracture point. SEM analysis does however
reveal that cracks are developed in the particles, gradually increasing with increasing load
and deformation. These types of particles have very little recovery. The paper will
include a series of load-displacement curves for the different polymer materials tested as
well as discussion of eventual failure modes (cracks etc.) taking place in the particles.
QUANTIFYING REAL-TIME CHANGES OF NANO-SCALE
INTERACTIONS AT SURFACES USING QUARTZ CRYSTAL
MICROBALANCE WITH DISSIPATION MONITORING
Archana Jaiswala, Stoyan Smoukovb, Mark A. Poggia and Bartosz
Grzybowskib. a Q-Sense Inc, Glen Burnie MD 21061, b Department of
Chemical and Biological Engineering, Northwestern University, Evanston, IL
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In the present study, we have investigated the ability of quartz crystal microbalance with
dissipation monitoring (QCM-D) to quantify the interaction of particles at surfaces. We
first will present recent results that address the effect of stagnant and dynamic motion of
charged nanoparticles solutions on their adsorption onto silica surfaces. We were able to
follow the real-time assembly (in liquid) of these chemically-modified particles. By
simultaneously quantifying the changes in surface mass and viscoelasticity during the
adsorption process, we were subsequently able to model the adsorption characteristics of
these particles. We will also discuss recent advances that have been made in regards to
using QCM-D to follow the assembly of biological nanoparticles (liposomes) onto
surfaces.
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ADSORPTION OF LOW MOLECULAR WEIGHT ISOTHIAZOLINE
BIOCIDES ON MINERALS AND THEIR SUBSEQUENT DESORPTION
FROM A PAINT FILM
Yao Kangaa,b, Jarrod Harta, David Gittinsa, Richard Greenwoodb, Neil
Rowsonb and David Skusea, (a) Imerys Minerals, Par Moor Centre, Par Moor
Road, Par, Cornwall, PL24, 2SQ, United Kingdom, (b) Department of
Chemical Engineering, University of Birmingham, Birmingham B15 2TT,
United Kingdom; [email protected]
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The adsorption of active components such as biocides onto powders has become a very
attractive process in the last few decades, especially in the food, drugs, paints or
cosmetics sectors. In this paper, the potential of such powder-based carriers to allow the
rate-controlled desorption of biocides in exterior paint films is explored. Initial
experiments were conducted to determine the adsorption isotherms of two isothiazoline
biocides, 2-octyl-4-isothiazolin-3-one (OIT) and the blend of 5-chloro-2-methyl-4isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (CIT/MIT) on a range of minerals
of differing surface areas and morphologies. These minerals were: a bentonite clay, an
halloysite, an amorphous silica and various grades of kaolin. The desorption profiles of
free OIT and minerals coated with OIT, both added to an exterior paint formulation, were
studied in order to assess the kinetics of release of the biocide from the films. The paints
made were applied to flat panels using a paint applicator, at 50 µm in thickness. The
levels of biocide desorbed in constantly stirred water with time were measured using
High Performance Liquid Chromatography (HPLC). Finally, the potency of the biocides
was determined by growing Pseudomonas Aruginosa micro-organisms in bioassay
experiments. Adsorption data obtained revealed that the biocide adsorbed to the minerals
by varying degrees. The desorption data showed that the bentonite carrier system took
over 48 hours to release half of the biocide from the paint film, compared with just 2
hours for the silica and the kaolin. The half-life of desorption for free (unabsorbed) OIT
in the paint was approximately 1 hour. The bioassay results showed that CIT/MIT was 13
and 17 times more effective at reducing the growth of the micro-organisms than OIT
when the kaolin and the silica were used respectively as carriers. Work is currently
underway to determine the release profile of OIT from several other substrates (including
some synthetic options).
HETEROGENEOUS DYNAMICS IN A DRYING COLLOIDAL THIN
FILM
Frank Scheffold, University of Fribourg, Department of Physics, Chemin du
Musée 3, 1700 Fribourg, Switzerland; [email protected]
200
The drying of a paint film is driven by the evaporation of the solvent and compaction of
the solid component. In the course of this process the suspended particles undergo a
continuous transition from liquid to an amorphous solid. Due to the evaporation of water
the particle dispersion concentration increases until the colloids are dynamically arrested
and subsequently the remaining water evaporates from the porous solid film. We report
127
on the observation of spatially and temporally heterogeneous dynamic properties of such
a drying paint film. In order to access spatial variations with dynamic light scattering we
present a new laser-speckle imaging experiment. We show how time and space resolved
data can be recorded: The new concept is to study statistics of the near-field speckles
produced by light diffusively reflected from the superficial volume of a strongly
scattering medium. We use a spinning ground-glass disk to scramble the incident beam
which allows us to create a large number of statistically independent optical
configurations at each point in the imaging plane. Our approach provides a real-time twodimensional imaging of normalized intensity correlation (ICF) or structure function
(ISF). Using this method we can access ensemble averaged dynamic properties on length
scales as small as ten micrometers over the full field of view.
INTERFACIAL ELECTROSTATICS OF MONOLAYER-PROTECTED
GOLD CLUSTERS BY MOLECULAR PROBES
Victor Chechik,1 Vadim K. Khlestkin,2 Julya F. Polienko,2 Maxim A.
Voinov,3 and Alex I. Smirnov,3 1University of York, Heslington, York YO10
5DD, United Kingdom; 2Novosibirsk Institute of Organic Chemistry,
Novosibirsk 630090, Russia; 3Department of Chemistry, North Carolina State
University, Raleigh, NC 27695-8204, USA; . [email protected]
201
Properties of monolayer-protected gold nanocluster’s (MPCs) interface are generally
manipulated through rational design and synthesis of the coating ligands. This is the key
strategy for designing MPCs for biodiagnostics, bio- and chemical sensors, drug/DNA
delivery, imaging, and biomolecular recognition purposes. Both stability and interactions
of gold nanoparticles with proteins and DNA are governed by the surface potential
resulting from the charge layer developed at the nanoparticle aqueous interface. Here we
present a molecular probe technique for accessing interfacial surface electrostatics of
ligand-protected gold nanoparticles. A series of ligands with variable length of the
hydrocarbon bridge between the anchoring sulfur and the reporting pH-sensitive nitroxide
is described. The protonation state of this probe is directly observed by EPR
spectroscopy. For tiopronin-protected Au nanoparticles we observed an increase in pKa
of up to ca. 1.1 pH units that was affected by the position of the reporter moiety with
respect to the monolayer interface.
COMPARISON AND ANALYSIS OF THREE P.A.T. TECHNIQUES IN A
PILOT-SCALE FLUIDIZED BED GRANULATOR
Ai Tee Tok1, Xue Ping Goh1, Wai Kiong Ng1, Reginald B.H. Tan1,2;
1
Institute of Chemical and Engineering Sciences 1 Pesek Road, Jurong Island,
Singapore 627833; [email protected]; 2Department of Chemical
and Biomolecular Engineering, The National University of Singapore, 4
Engineering Drive 4, Singapore 117576.
202
Recent US Food and Drug Administration (FDA) guidelines encourage the development
of Process Analytical Technology (PAT) techniques to develop more in-depth process
128
understanding, improve process control and assure higher conformance to product
specifications. However, the use of PAT in secondary pharmaceutical manufacturing is
seldom implemented on production-scale as these techniques are still not fully
established. To address this need, an experimental study has been conducted to apply
three PAT tools simultaneously to monitor the progress of a granulation process in a
pilot-scale fluidized bed (ID 0.3 m and height 0.6 m). Real-time analysis using focused
beam reflectance measurement (Lasentec FBRM) and near-infra red spectroscopy
(Bruker NIR) are conducted using in-line probes inserted into the bed. Acoustic emission
measurements (Physical Acoustic AE) are performed by attaching acoustic sensors at two
locations on the external wall of the fluidized bed. Powder samples collected at regular
intervals during the granulation process are characterized off-line using Malvern laser
diffraction (particle size distribution), scanning electron and optical microscopy
(morphology) and loss on drying (moisture content). PAT data comprising chord length
distribution and chord count (from FBRM), absorption spectra (from NIR) and average
signal levels and counts (from AE) are compared with off-line particle properties, in
order to investigate the response and sensitivity of each PAT tool in detecting the three
granulation rate processes (wetting and nucleation, aggregation and growth, breakage).
By comparing the results obtained using the three techniques, the work aims to provide
some guidelines on the selection of a suitable PAT tool for process design and pilot-scale
trials. Hands-on experience gathered and the difficulties encountered when using each
PAT technique will also be discussed.
HIGH-THROUGHPUT NON-AQUEOUS DISPERSION
POLYMERIZATION USING A MICRO-REACTOR AND ON-LINE
DYNAMIC LIGHT SCATTERING
Thuy T. Chastek, Thomas Q. Chastek, Kazunori Ilda, Steven D. Hudson,
Michael J. Fasoka, Polymers Division, National Institute of Standards and
Technology, 100 Bureau Drive Gaithersburg, MD 20899-8542, USA;
[email protected]
203
Polymer particles are finding increasingly important applications in both industry and
academia, for example acting as specialty additives to coatings, pharmaceuticals, and
personal care products. An important issue in preparing these particles is controlling their
size and size distribution. A variety of factors can potentially influence these properties,
which makes optimization of synthesis conditions somewhat demanding. Therefore,
high-throughput (HTP) methods for developing new polymer particle synthesis strategies
are of great value. Common synthesis challenges, such as isolation and purification of
final products are not necessary to evaluate the size and size distribution of polymer
particles, thereby simplifying HTP strategies. In this work, high-throughput non-aqueous
dispersion (NAD) polymerization of poly(methyl methacrylate) (PMMA) and
measurement of PMMA latex are performed using a new micro-semi batch reactor
integrated with online dynamic light scattering (DLS). The metallic microreactor was
designed to handle the harsh conditions associated with NAD polymerization. On-line
DLS was implemented for in situ monitoring of the PMMA latex particle size and size
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distribution. Polymeric surfactants consist of PMMA and poly(octadecyl methacrylate)
(PODMA) with systematically varied composition, architecture, and molecular weights.
These were synthesized under conventional batch condition by Cu-mediated atom
transfer radical polymerization (ATRP). Comb polymers grafted with polyisoprene (PI)
were designed and synthesized from backbone of a random MMA and glycidyl
methacrylate copolymer. The properties of the surfactants were found to significantly
affect the size and size distribution of the resulting particles. The dispersion
polymerization of MMA using random copolymers as surfactants resulted in relatively
large particles (~ 1 μm), whereas copolymers and comb polymer yielded nano-size
particles (< 500 nm).
NANOPARTICLE MEASUREMENT BY SPECTROSCOPIC MIE
SCATTERING
Rick Trutna, Maozi Liu, Danielle Chamberlin and Judith Hadley, Agilent
Technologies, Inc., 1400 Fountaingrove Parkway, Santa Rosa, CA 95409,
In this paper we present a spectroscopic technique for measuring particle size. The
technique utilizes a UV-Visible spectrophotometer to measure the attenuation spectrum
of a particle dispersion due to scattering. Using the Mie scattering theory, we compute
the particle size distribution and particle concentration that best matches the measured
scattering spectrum. While the operating range is material dependent, we have found that
the instrument can measure particles sizes from 10 nm to 15 microns. The technique
involves minimal sample preparation and clean up, and is fast. A measurement time of
less than 10 seconds allows measurement of samples where dispersion stability is an
issue or when the particles are dense and the sedimentation rate make traditional
measurement techniques challenging. Since the technique does not rely on observing the
Brownian motion of particles, the samples may be stirred or flowed during the
measurement via the use of a stir bar accessory or utilizing flow through cells. An
additional advantage of the technique is the ability to measure highly concentrated
colloids at or near process concentrations with no dilution. Fast measurement time
enables the study of samples changing over short timescales. This information can be
critical in reaction kinetic studies and aggregation studies in biological systems. As well
the fast measurement time has advantages for measurement of inorganic systems. For
example, the dispersion of metal powders in water has been little studied due to two
major problems: the complex colloidal behavior in which not only oxidation and
hydrolysis but also dissolution occurs, depending on pH and temperature, and the density
of most metals that promotes fast settling. Nickel powders have a high density, so that
electrostatic repulsion is not sufficient itself to overcome the tendency to settle. With
further complications due to its magnetic properties, surface modification techniques
utilizing steric stabilization are required to prevent agglomeration. Obtaining accurate
measurements the particle size of Ni is challenging in this environment of dispersion
instability. The fast measurement times of our UV-Visible particle sizing technique
facilitate measurement of such unstable systems. We report experimental results
comparing particle size measurements via this technique to SEM image analysis
demonstrating the accuracy of the measurement. We also present experimental results
demonstrating the capability of this technique to accurately measure the concentrations of
204
130
populations in difficult bi- or multi-modal particle size distributions. We demonstrates
the resolution capability of the UV-Visible particle sizing instrument with a sample of
equal concentrations of 200nm and 300nm polystyrene latex. Such resolution has also
been demonstrated for metal nanoparticles as well, for example with 80nm and a 150nm
gold standard dispersions mixed in a 1:3 ratio. We also demonstrate the sensitivity of the
method with the detection of 5 % v/v 100 nm polystyrene latex particles in a background
of 95% v/v 3 µm particles. We believe this combination of fast measurement time, high
resolution, and ease of sample preparation offers distinct advantages over existing
techniques and enables new measurements.
EXPERIMENTAL CORRELATION BETWEEN PARTICLE SIZE AND
LASER INDUCED INCANDESCENCE (LII) TIME DECAY IN TiO2
FLAME SYNTHESIS
Carla Bellomunno, Silvia Maffi, Francesco Cignoli*, Giorgio Zizak,
Giuliano Angella, CNR-IENI, Via R. Cozzi 53, 20125 Milano Italy,
[email protected]; [email protected]
205
Particle size evaluation is a major issue in nanopowder synthesis. Many measurement
techniques based on different principles are available to test synthesized powders, that as
a whole give a good coverage over size range, output data meaning, and applicability to
particles of varied nature. In general, these methods are applicable only to the final
product and the response is typically available after some time. In the case of flame
synthesis, in spite of the highly hostile environment, some perspectives of direct access
actually exist, thanks to the gaseous nature of the same environment. This was pointed
out several years ago as a promising extension of the Laser-Induced Incandescence (LII)
method widely used in soot diagnostics. Nevertheless, very few experiments were
reported in the literature after the initial preliminary work. In particular, no LII
experiments have been reported so far on titania flame synthesis, in spite of the fact that
this is a typically flame-made nanosized powder. Here we present our results in LII
experiments during TiO2 flame synthesis from TTIP vapors. Titania LII was generated by
irradiation with the 4th harmonic of a pulsed Nd:YAG laser. The response of titania
particles to laser excitation during the synthesis process was evaluated on the basis of
spectral analysis and of Time Resolved LII (TIRE-LII). With the first method, the
reaction of the particles to strong laser irradiation was studied. The fluence range suitable
for the emission of a radiation predominantly due to incandescence was determined.
Under those conditions, TIRE-LII signals were recorded at several heights above the
burner, that is at different particle growth stages (particle size roughly from 10 nm to 50
nm). A sensitivity of the incandescence signal time decay to the particle growth was
clearly observed. At the same locations a rapid insertion device was used to collect
material samples on a Transmission Electron Microscope grid (thermophoretic sampling).
From the TEM images, an average particle size is obtained, that is compared with the
time decay of the incandescence signal at the corresponding flame location. This will be a
first step towards the measurement of the particle size directly during the synthesis
reaction.
131
NANOPHOTONIC DEVICES USING COUPLED NANOPARTICLES
WITH VIRTUAL PHOTONS AND POLARITONS
Tadashi Kawazoe, Department of Electronics Engineering, University of
Tokyo 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan.
[email protected].
206
So far, we have proposed several kinds of nanometric optical device (nanophotonic
device) using a coupled nanoparticles (quantum dots: QDs), e.g., AND-gate, NOT- gate,
optical nanofountain, and so on. The optical near-field interaction is the most dominant
interaction for QDs with their separation of 5nm-100nm. Usually, the optical interaction
in the near-field region is described as a dipole-dipole interaction. In vacuum, this
description gives a good approximation. However, practical QDs are embedded in some
matrixes or on substrates. So, we proposed the near field interaction to explain the optical
interaction in the near-field region, which include the effects of the matrixes and the
substrate. We consider that the interaction particle is not a photon but a polariton for the
optically coupled QDs in the near-field region. In this point of view, we have observed an
optically-forbidden energy transfer between QDs and demonstrated nanophotonic devices
using QDs. We discuss the principles and the demonstrations of nanophotonic devices.
Additionally, we mention the single excitation energy transfer between QDs and a single
photon emission from the coupled QDs system using the optical near-field interaction.
This single photon emitter has two blockade mechanisms and a high purity single photon
is obtained.
DRIVING FORCES IN NANOPARTICLE ASSEMBLY
Nicholas A. Kotov, Departments of Chemical Engineering, University of
Michigan, Ann Arbor, MI; [email protected]
207
Physical properties of nanoparticles and nanowires are currently well understood. The
next frontier is conceptualization of larger structures, such as nanoscale assemblies. This
talk will discuss two paradigms in this field: (1) spontaneous assembly of nanoparticles
and (2) quantum mechanical interactions of metallic and semiconductor building blocks
in nanoscale assemblies. Anisotropic forces arising between nanocrystalline particles
drive the self-assembly behavior of these colloidal particles. Interaction anisotropy
between CdTe nanoparticles in solution leads to their spontaneous, template-free
organization into free-floating sheets. Electrostatic interactions arising from a dipole
moment and a small positive charge combined with directional hydrophobic attraction
between the nanoparticles are the driving forces for the self-assembly, which we
demonstrate by computer simulation. We found that nanoparticles show conceptual
similarities with assembly of proteins. This supposition was recently confirmed by
assembly of nanoparticles into spiral systems similar to those found in many biological
systems. Electronic interactions in nanoparticle assemblies represent one of the
fundamental problems of nanotechnology. Excitons and plasmons are the two most
132
typical excited states of nanostructures, which were shown to produce coupled electronic
systems. The concept of these interactions between the Au and CdTe nanoparticles and
nanowires will be discussed in terms of quantum mechanical coupling of excited states
and unusual optical effects. As such, in presence of dynamic component for excitons
theory predicts that emission of coupled excitations in nanowires with variable electronic
confinement is stronger, shorter, and blue-shifted. These predictions were confirmed with
high degree of accuracy in molecular spring assemblies, where one can reversibly change
the distance between the exciton and plasmon. The prepared systems were made proteinsensitive by incorporating antibodies in molecular springs. Modulation of excitonplasmon interactions can serve as wavelength-based biodetection tool, which can resolve
difficulties of quantification of luminescence intensity for complex media and optical
pathways.
LARGE-SCALE FABRICATION OF SINGLE ELECTRON DEVICES
UTILIZING COLLOIDAL NANOPARTICLES
Seong Jin Koh, Department of Materials Science and Engineering,
University of Texas at Arlington, 500 West 1st ST Woolf Hall RM325,
Arlington, TX 76019, [email protected]
208
ingle electron devices, having the capability of systematically controlling the transport
and storage of single electrons, have brought a lot of attention as promising candidates
for future nanoscale devices and sensors. However, their fabrication requires arranging or
defining device components with nanoscale precision for electron tunneling to occur in a
controlled way. The nanoscale geometrical requirement has limited their fabrication to a
few units at a time. This talk presents a large-scale and chip-level fabrication of single
electron devices. This was realized by utilizing colloidal nanoparticles as Coulomb
islands and implementing CMOS fabrication technology as well as self alignment of
source and drain electrodes over a large area. We demonstrate clear Coulomb staircase
and Coulomb blockade behavior at room temperature. Although large-scale fabrication
has been demonstrated for single electron devices, similar approaches may provide a
useful pathway toward realization of integrated systems of other nanoscale devices and
sensors.
LIGHT-ACTIVATED NANOPARTICLES FOR ION CHANNEL
APPLICATIONS
Laura Steller, Wolf D. Habicher, and Reiner Salzer, IFW Dresden,
Helmholtzstr. 20, D-01069, Dresden, Germany; [email protected]
209
Our target is the development of artificial ion channels based on nanosized particles that
can be actuated by light and thus controlled efficiently. Light-activated artificial channels
formed by these organic compounds are aimed at eliminating of the stochastic
mechanism of artificial channels. Such a reversible photocontrol should be a powerful
tool for using artificial ion channels as the basis for the development of biosensors, new
pharmaceuticals and drug delivery systems, as photoswitches, and in the field of
133
microfluidics. Our synthesized particles are devided in two regions: the gate part and the
body part. The gate part is based on fast, light-driven azogroups that use steric differences
between trans and cis isomers. The azogroups are attached to the transmembrane artificial
ion channel body part formed by a special type of calix[4]resorcinarene. Such
photochromic systems are reversible, switchable and exhibit photo-responsive
conformational effects under different irradiation conditions. Information about the
successfully artificial channel activity of our compounds are provided by the Patch-clamp
technique, commonly used for electrophysiological analysis.
NANOPARTICLES FOR MAGNETIC RECORDING: THE PROS AND
CONES OF SELF-ASSEMBLY
H.-G. Boyen1, U. Wiedwald2, J.-U. Thiele3, A. Romanyuk4, B. Kern2, K.
Fauth5, C. Antoniak6, M. Farle6, P. Oelhafen4, U. Herr7, 1Institute for
Materials Research (IMO), Hasselt University, 3590 Diepenbeek, Belgium,
2
Institut für Festkörperphysik, Universität Ulm, 89081 Ulm, Germany,
3
Hitachi Global Storage Technologies, 3403 Yerba Buena Road, San Jose,
CA 95135, 4Institut für Physik, Universität Basel, Klingelbergstr. 82, 4056
Basel, Switzerland, 5Max-Planck-Institut für Metallforschung, Heisenbergstr
3, 70569 Stuttgart, Germany, 6Experimentalphysik—AG Farle, Fachbereich
Physik, Universität Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg,
Germany, 7Institut für Mikro- und Nanomaterialien, Universität Ulm, 89081
Ulm, Germany; [email protected]
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Further reduction of the volume of magnetic structures appears as a natural route towards
the enhancement of information density stored by corresponding magnetic devices. Such
a reduction, however, generally results in a superparamagnetic behavior for any material
below a critical volume, the value of which is governed by its magnetocrystalline
anisotropy energy. Among the materials with a large anisotropy energy, FeXPt100-X alloys
in the face-centered tetragonal (L1o) phase play a vital role since various techniques
based on self-organization are available for the synthesis of corresponding nanoparticles
and their organization into two-dimensional arrays. It turns out that, in the as-synthesized
state, Fe50Pt50 particles exhibit a face-centered cubic structure, which has to be
transformed by annealing at elevated temperatures into the desired L1o phase. Such phase
transformation, however, can be achieved only within a limited range of compositions (x
≈ 40-60) raising the important question of whether or not statistical fluctuations during
self-assembly might result in strong variations of the magnetic properties as well. In this
case, even for particle ensembles with perfectly uniform size and shape, after the
annealing step, a significant amount of superparamagnetic particles might still be present,
thereby drastically reducing the potential of this material to be used in forthcoming magnetic data storage applications. In order to address this fundamental problem with a
method sensitive to fluctuations within macroscopic areas, X-ray photoelectron
spectroscopy has been performed on FeXPt100-X reference films (26 ≤ x ≤ 68) in order to
study chemical shifts and line shapes of appropriate core levels (Fe-2p, Pt-4f) induced by
alloying. These reference data are then used in a second step to decompose core level
spectra measured on Fe50Pt50 nanoparticle ensembles (prepared by colloidal and micellar
methods) into chemically shifted components, thereby allowing to estimate the range
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ostoichiometry fluctuations for the different preparation techniques.
MEMORY EFFECTS IN INSULATORS INCORPORATING
SEMICONDUCTING OR METALLIC NANOPARTICLES
Dimitris Tsoukalas, School of Applied Sciences, National Technical
University of Athens, Zographou 15780, GREECE; [email protected]
211
An application field of interest during last years in microelectronics is the use of
nanoparticles to store electronic charge. The so called nanoparticle memories present
advantages over conventional flash electronic memories that make use a continuous
polysilicon layer to store charge. These advantages relate mainly to better scaling
properties of tunneling oxide through which the memory is charged and discharged that
consequently allows for more aggressive scaling of the corresponding memory device. In
this work we investigate a new method to fabricate either metallic or semiconducting
nanoparticles at room temperature. The nanoparticle deposition technique is based on a
physical vacuum deposition (PVD) process. The technique allows for controlled density
and size deposition of nanoparticles. Particles are generated using a high-pressure
magnetron sputtering device and carried away from the target area by the discharge gas
into a condensation zone where nanoparticles are grown. The nanoparticles after being
swept through this zone enter the main chamber through a final aperture and they are
soft-landed on the substrate. It is thus possible to obtain nanoparticles with a size that
according the process conditions used it ranges from 2 – 12 nm and an area density up to
1012 cm-2. As an illustrating example nickel nanoparticles are deposited at room
temperature over a tunneling thermal SiO2 layer followed by the deposition of HfO2 as a
control insulator. Simple MOS capacitor structures are used to analyze the memory
properties and charge storage capability of the nanoparticles embedded in the above
insulator matrix.
FROM FOAMS TO ‘DRY WATER’: PHASE INVERSION OF PARTICLESTABILISED MATERIALS
Bernard P. Binks and Ryo Murakami; Surfactant and Colloid Group,
Department of Chemistry, University of Hull, Hull HU6 7RX, United
Kingdom; [email protected]
212
Phase inversion of particle-stabilised emulsions from oil-in-water to water-in-oil can be
achieved either by increasing the particle hydrophobicity at constant oil:water ratio
(transitional) or by increasing the oil:water ratio at fixed particle wettability
(catastrophic). Here, we describe for the first time the corresponding inversion of
particle-stabilised air-water surfaces, not achievable up to now with surfactant molecules.
The nanoparticles are those of fumed silica, made hydrophobic by reaction with
dichlorodimethylsilane. Inversion from air-in-water foams to water-in-air free flowing
powders is effected via both transitional and catastrophic inversion. The novel materials
so produced represent a way of encapsulating air or water, with the adsorbed particle
layer providing a means to control the release of gaseous or liquid components
respectively.
135
LASER SYNTHESIS OF NON STOICHIOMETRIC TITANIUM OXIDE
NANOPARTICLES
B. Pignon, L. Combemale, S. Marguet, D. Porterat, C. Reynaud, N. HerlinBoime, Nathalie Herlin-Boime, Service des Photons, Atomes et Molécules,
Laboratoire Francis Perrin (CEA-CNRS URA 2453), Bat 522 CEA Saclay,
91191 Gif/Yvettte Cedex, France, [email protected]
213
Oxide nanoparticles such as TiO2 have different properties according to their structure.
Moreover, incorporation of heteroatoms in the TiO2 network may favour photocatalytic
activity or absorption of solar light. Laser pyrolysis is an efficient method for the
synthesis of various nanoparticles and in particular TiO2. By tuning the experimental
parameters (laser power, atmosphere...), the flame temperature was controlled and
nanoparticles (with or without dopants) were obtained in antase or rutile form with ratio
in the range 10/90 to 90/10 from the pyrolysis of an aerosol of liquid
Titaniumtetraisopropoxid. We present here recent results on the synthesis of N-doped and
undoped nanoparticles. At high laser power, i.e. at high flame temperature, reduction
reactions can take place and the particles are often produced in a substoichiometric phase:
crystalline TiO, Ti3O4 or Ti4O7 were identified by X-Ray diffraction in various samples
according to different experimental conditions. First results illustrating the consequences
of this structural evolution on the properties of nanoparticles will also be presented with
special emphasis on the optical properties in the visible-UV range.
SUPRACOLLOIDAL STRUCTURES THROUGH LIQUID-LIQUID
INTERFACE DRIVEN ASSEMBLY
Stefan A. F. Bon, Catheline A. L. Colard, and Patrick J. Colver, Department
of Chemistry, University of Warwick, Coventry CV4 7AL, UK.;
[email protected]; www.stefanbon.com
214
We would like to discuss in depth our new and unpublished results on Pickering
stabilized miniemulsion and suspension polymerization. We will report the synthesis of
polymer latexes (styrene, (meth)acrylates and vinyl esters) using Laponite clay and
colloidal silica as the exclusive stabilizers. We have developed a model which allows us
to correlate particle size distributions with the amount of Pickering stabilizer used. We
will discuss the influence of monomer hydrolysis and the addition of conventional
surfactants on the polymerization kinetics and particle size distribution. In case of
colloidal silica we will discuss the packing coordination of the silica nanospheres. With
respect to liquid-liquid interface driven assembly on micronsized droplets we will show
that Pickering systems are a tool to the design of non-spherical and high-aspect ratio
microspheres. Moreover, we will demonstrate a new set-up to produce Janus particles
using Pickering stabilization as a tool. Finally, we will report on the concept of using
self-assembly of supracolloidal structures, as a versatile strategy to prepare cellular
polymer materials. These materials are light-weight as they show a very high porosity,
typically > 80%, resembling cellular natural objects such as sponges, bone, and wood.
136
We will show that we can control the properties of our cellular supracolloidal materials
by variation of the building blocks from which the individual supracolloidal units have
been build, and by use of different scaffolding techniques, such as radical polymerization
of the continuous phase. It is our belief that our approach widens the window of the
design of cellular materials and has scope to deliver exciting innovations in areas such as
chromatography, cell storage, catalysis and sensors/detectors.
NOVEL ASSEMBLY APPROACH TOWARDS ENERGY-MATERIAL
PARTICLES
Qiangfeng Xiao, HiesangSohn, Kimerbly Cross, Ding Weng, and Yunfeng
Lu, Chemical and Biomolecular Engineering Department, University of
California Los Angeles, 420 Westwood Plaza, Box 951592, Los Angeles, CA
215
There has been an increasing interest in developing novel materials that are suitable for
energy storage and conversion. Some representative examples include the design and
synthesis of highly porous materials for hydrogen storage, fuel cell electrode materials,
supercapacitor, and battery electrodes. Various methods have been developed to
synthesize such materials. Self-assembly, a method that utilizes noncovalent interactions
to organize suitable building blocks into porous scaffolds has been emerging as a
promising synthesis approach. Generally, an assembly approach allows precise structure
and composition control through the judicious choice of building blocks, manipulating
inter-building-block interactions, and boundary conditions. In this presentation, we will
report the synthesis of carbon/ceramic nanocomposite particles through an assembly
approach. Briefly, carbon and ceramic building blocks were organized into ordered
mesostructured nanocomposite particles through an aerosol-assisted assembly process
using surfactant as the pore-structure-directing agent. Subsequent carbonization process
converts the particles into mesoporous carbon/ceramic particles with high electronic
conductivity and significantly enhanced corrosion resistance. We will also report the
synthesis of novel metal, metal oxide, semiconductor, and their alloy or nanocomposite
particles in non-aqueous media. Traditionally, most of the assembly processes, such as
the synthesis of mesoporous silica, has been conducted in aqueous media; this discovery
enables the synthesis of a large family porous materials for energy-related applications,
as well as other important applications.
ULTRABRIGHT LEAD SELENIDE QUANTUM DOT NANOCLUSTERS
Christopher M. Evans, Li Guo, Jeffrey J. Peterson and Todd D. Krauss,
Department of Chemistry, University of Rochester, Rochester, New York,
216
Semiconductor quantum dots (QDs) have demonstrated enormous potential as
superior fluorophores for biological imaging applications. Especially attractive is
the possibility for imaging at near-infrared (NIR) wavelengths between 700 and
137
1000 nm, where there is reduced absorption by biological fluids and where organic
dyes emit poorly. However, a fundamental weakness of QDs regarding biological
imaging applications concerns their relatively large size. Biocompatible QDs are
approximately 10–15 nm in diameter, with hydrodynamic diameters typically
exceeding 25 nm. As such, it is virtually impossible for QDs to enter the cell
through carrier-mediated mechanisms. Here, we report a facile and room
temperature synthesis of PbSe quantum dot nanoclusters that emit in the NIR with
remarkably high fluorescence quantum yields (typically >50%). With core
diameters estimated to be < 2 nm, these clusters concomitantly address the optimal
requirements for biological labeling: small hydrodynamic radius, high QY, water
solubility and long-term photostability.
INTEGRATING TOP-DOWN FABRICATION WITH BOTTOM-UP
SELF-ASSEMBLY
Vincent M. Rotello, Department of Chemistry, University of Massachusetts,
Amherst MA 01003 USA; [email protected]
217
Polymer-mediated self-assembly of nanoparticles is a versatile and modular approach to
the creation of nanostructured thin films and nanocomposite materials. We have
developed a number of methodologies that provide nanostructured and nanopatterned
materials. In our ongoing research, we are integrating these bottom-up self-assembly
strategies with fabrication strategies to create functional devices and materials. The
formation, properties, and applications of these materials will be discussed.
INCORPORATION OF LAPONITE CLAY PLATELETS INTO POLYMER
LATEXES: EVIDENCE OF CLAY LOCALIZATION BY CRYO-TEM
IMAGING
V. Mellon1, N. Negrete-Herrera1, J-L. Putaux2, T. McKenna1, E. BourgeatLami1 - 1Chimie, Catalyse, Polymères, Procédés (C2P2) - Equipe Chimie et
Procédés de Polymérisation (LCPP) - UMR 5265 CNRS/CPE Lyon/UCBL –
ESCPE - Bât. 308F – 43, Bd. du 11 Novembre 1918 - BP 2077 - 69616
Villeurbanne Cedex, France. 2Centre de Recherches sur les Macromolécules
Végétales, ICMG-CNRS, BP 53, F-38041 Grenoble Cedex 9, France ;
[email protected]
Over the past decade, the concept of nanostructured materials, i.e. materials whose
structural elements (clusters, crystallites, molecules or particles) have dimensions in the
nanometer range, has attracted a great deal of attention. Indeed, these materials provide
the unique opportunity to tailor the constituent properties toward optimal material
behaviour by carefully designing the nanostructure. For example, in the case of polymerclay nanocomposites, it is generally admitted that a greater mechanical reinforcement is
achieved with fully exfoliated structures rather than intercalated structures. A survey of
the recent literature reveals that a great deal of effort has been devoted to synthesize
polymer/clay nanocomposites with exfoliated clay layers. These methods include bulk
218
138
polymerization, solution polymerization, suspension polymerization and emulsion
polymerization, to name a few. The type of polymerization method will greatly influence
the way the clay interacts with the polymer chains and its ability to swell and exfoliate.
Among these methods, emulsion polymerization can be advantageously used by
exploiting the natural swelling of the clay platelets in aqueous media. Provided that
interactions are created between the clay surface and the growing polymer chains, this
technique enables the clay platelets to be located on the surface of the polymer latex
particles resulting in a honeycomb structure of the free standing film after water
evaporation. If one wants to encapsulate the clay into the polymer particles, miniemulsion
polymerization needs to be used. In this process, nanometric monomer droplets
(assimilated to nanoreactors) containing the clay platelets are converted into a similar
number of particles of related size and composition. In this communication, we will
present some of the strategies recently developed in our laboratory to synthesize polymer
latexes containing Laponite clay platelets located either on the surface or inside of the
composite particles using emulsion and miniemulsion polymerization. Unambiguous
evidence of clay distribution and localization within the latex samples has been provided
by cryo-TEM images which gave insights into nucleation mechanism and nanostructure
formation.
Session A5– Invited Paper
STRATEGIES FOR IMPLEMENTING NANOMATERIALS IN
COMMERCIAL APPLICATIONS
G. Skandan, NEI Corporation, Somerset, NJ 08873, USA;
[email protected]
219
The last few years has seen many Nanotechnology start-ups come and go. The low
hanging fruit that these companies were supposed to capitalize upon in a three-to-five
year time frame did not materialize in a disproportionately large number of cases. The
widespread enthusiasm in the early years of the millennium that spawned these
enterprises has certainly subsided. Even multinational corporations have taken a careful
watch-and-proceed approach, particularly keeping in mind the potential negative
environmental and health effects of nanomaterials. It would appear that the traditional
model of building a manufacturing infrastructure while simultaneously developing
markets for the products, has not worked in the Nanotechnology space, which has led to
investor fatigue. This presentation will analyze problems with conventional business
plans followed by a discussion of NEI’s implementation of alternative business models.
Three areas of business development will be highlighted: Li-ion battery electrode
materials, corrosion protection, and functional hard coatings on polymers. In each case a
different business strategy was adopted to get products into the market.
Session A5– Contributed Paper
THE NUCLEATION PHASE: AN EVALUATION OF TWO MODELS.
Ingo H. Leubner, Crystallization Consulting, 35 Hillcrest Drive, Penfield,
NY 14526-2411, USA, [email protected]
220
Two competing models are available for the modeling of the crystal nucleation phase.
139
Both start with the formation of agglomerates from the reactants. The major practical
outcome is the concept of critical nucleus. From here, the two models take different
paths. The well known classical model attempts to model the nucleation rate, J. This
nucleation rate, J, is considered constant during the nucleation phase. On the other hand,
the BNG model focuses on the total number of crystals formed, Z. The crystal number is
derived from growth of the critical nuclei, the crystallization efficiency, and reactant
addition rate. These factors determine the course of nucleation and predict an end of
nucleation as the function of the crystal growth rate. In this model, the nucleation rate,
‘J’, increases from zero to a maximum, followe by decrease until nucleation ends. During
this process, the crystal number and size distribution is determined. The BNG model
consequently leads to an explicit, factor free model which quantitatively relates the
number of crystals formed to reactant addition rate, crystal solubility, temperature, and
the effects of crystal ripeners and restrainers. The consequences of these models on the
process of practical crystallizations will be included.
NEW INSIGHTS ON NANOPRECIPITATION BY SOLVENT SHIFTING
Julien Aubrya, Bernard Cabaneb, François Ganachauda,*; a) Institut Charles
Gerhardt, UMR CNRS 5253, Equipe IAM, Ecole nationale Supérieure de
Chimie de Montpellier, 8 rue de l’Ecole Normale 34296 Montpellier Cedex 5,
France; [email protected]; b) Laboratoire de Physique et Mécanique des
Milieux Hétérogènes - UMR CNRS 7636, École Supérieure de Physique et
de Chimie Industrielles, 10, rue Vauquelin 75231 Paris Cedex 05 France ;
[email protected]
221
“Solvent-shifting” is a very simple process by which hydrophobic molecules may be
dispersed in water as tiny (at least sub-micrometric) droplets of particles. The process
appears deceptively simple: the hydrophobic solute is first dissolved into a polar solvent
fully miscible with water, and then this solution is mixed with a large amount of water.
The solution becomes a non-solvent for the hydrophobic molecules, which then phase
separate as small droplets or particles. Industrially, the “solvent shifting” route is used to
manufacture sub-micrometric particles of Vitamin A, dyes and drugs, since it has
numerous advantages over other processes such as high-pressure homogenization or
grinding, in particular the very small sizes that are easily achieved (most of the times
nanometric), the simple nature of equipment, the low energy costs, and the easy
implementation as an on-line process. On the other hand, different initial conditions and
different composition pathways lead to different final results, which induced some
confusion and conflicts in the understanding of the thermodynamic of the system. In this
paper, we present some experimental results and theoretical considerations on pMMA
nanoprecipitation in water, using acetone and THF as solvents. From the setting up of the
phase diagram and microscopic and light scattering studies of particle size and
distribution, we will try to answer the following questions: what is the non-equilibrium
state from which the polymer solution starts its evolution (START)? Then, what pathway
does it follow as it evolves from this state (RUN)? Finally, in what state does it get
trapped at the end of this evolution (STOP)? We will also show that the nature, content,
phase dispersion of the surfactant has a great influence on the structure and size of the
140
final polymer particles.
METAL AND SEMICONDUCTOR NANOPARTICLE DEPOSITION AND
SEPARATION USING CO2-EXPANDED LIQUIDS
Christopher B. Roberts, Juncheng Liu, Kendall M. Hurst, Steven R.
Saunders. Department of Chemical Engineering, Auburn University, 210
Ross Hall, Auburn, AL 36849-5127, USA; [email protected]
222
A novel process will be described that utilizes the pressure tunable physico-chemical
properties of CO2 gas expanded liquid solutions to size selectively precipitate and
fractionate polydisperse metal and semiconductor nanoparticle dispersions into multiple
narrow size populations. Our work demonstrates that ligand stabilized nanoparticles can
be size selectively precipitated by simply controlling the addition of compressed CO2
antisolvent to an organic nanoparticle dispersion. This tunable gas expanded liquid
approach allows for rapid and efficient size separation while also reducing organic
solvent usage. The efficacy of this process has been demonstrated with several types of
metal and semiconductor particles at process scales ranging from microliters to >100
milliliters of an organic nanoparticle dispersion. In addition, this gas expanded liquid
driven nanoparticle deposition process has been utilized to create ordered thin films and
arrays of nanoparticles on device surfaces, such as MEMS devices, without the
detrimental interfacial dewetting effects inherent to liquid evaporation driven
nanoparticle deposition techniques.
SUPERCRITICAL PARTICLE FORMATION: KINETIC PARAMETERS
ESTIMATION
Yousef Bakhbakhi, Department of Chemical Engineering, King Saud
University, P.O. Box 800, Riyadh 11421, Saudi Arabia;
[email protected]
223
Depending on the considered particle formation mechanism, population balance model of
the gas antisolvent crystallization (GAS) process may include phenomena such as
primary nucleation, secondary nucleation, crystal growth, as well as agglomeration
and/or breakage (attrition) of crystals. The resulting equation is often of the integropartial differential form. A powerful numerical algorithm for the treatment of the
implemented population balance model structures was applied in this work. The method/
algorithm is a combination of the Lax-Wendroff and Crank-Nicholson methods.
Algorithm simulations were performed for changes in the main GAS process operating
parameters, i.e., the antisolvent addition rate and saturation level. The simulations were
performed at a process temperature of 25oC, while the antisolvent addition rate, Q A , was
varied between 1 and 100 ml/min, and the initial solute concentration was varied between
25% and 100% of the concentration ratio.
141
VISUALIZATION OF SPRAY AND PARTICLE CHARACTERISTICS OF
SAS PRECIPITATION OF PMMA, PVP, AND COPOLYMERS
Daniel L. Obrzut, Brian P. Sullivan, Andrew W. Monfort, Christopher B.
Roberts, and Steve R. Duke, Chemical Engineering, Auburn University, AL
224
Supercritical antisolvent (SAS) precipitation process experiments were performed to
directly relate spray properties to particle charateristics for a variety of operating
conditions and for several polymers and copolymers. A high-resolution imaging system
was used to study the spray characteristics of polymer/ethanol solutions in pressurized
carbon dioxide. The visualizations provide high magnification video of the jet emerging
from the spray nozzle and of the spray at various distances away from the nozzle tip. The
precipitated polymer particles were characterized using a scanning electron microscope.
Image processing and analyses were developed to measure jet breakup lengths, drop
properties, and particle characteristics. Studies were conducted with poly methyl
methacrylate (PMMA), poly vinyl pyrrolidone (PVP), and copolymers from the
monomers methyl methacrylate and vinyl pyrrolidone. Polymers and copolymers were
processed through SAS to observe the effects of their solubility in ethanol on the SAS
spray characteristics and the resulting particles. The solubilities of the copolymers were
influenced by varying the methyl methacrylate to vinyl pyrrolidone ratio, which reduces
the solubility in ethanol. Cloud point experiments were used to evaluate the saturation
concentrations in ethanol for the polymers and copolymers. Process visualizations
revealed that the spray of each polymer or copolymer solution into carbon dioxide had
similar jet breakup lengths and droplet diameter distributions, and that these spray
characteristics appear to be closely associated with the solvent (ethanol) properties.
Distinct spray regimes were observed by varying system pressure. The SEM images
showed variation in particle size distributions, and the presence of large particles and
microballoons, with significant influence identified relative to the solubility of the
polymer or copolymer in ethanol and to certain processing conditions.
SYNTHESIS, PROPERTIES AND PERSPECTIVES OF COMPLEX
NANOCRYSTAL STRUCTURES
Liberato Manna, National Nanotechnology Laboratory of CNR-INFM,
Distretto Tecnologico – Isufi, Via Arnesano Km 5, 73100 Lecce, Italy;
[email protected]
225
Current efforts and success of nanoscale science and technology are related to the
fabrication of functional materials and devices in which the individual units and their
spatial arrangement are engineered down to the nanometer level. One promising way of
achieving this goal is by assembling of colloidal inorganic nanocrystals as the novel
building blocks of matter. This trend has been stimulated by significant advancement in
the wet-chemical syntheses of robust and easily processable nanocrystals in a wide range
of sizes and shapes. The increase in the degree of structural complexity of solution-grown
nanostructures appears to be the natural direction toward which nanoscience will
increasingly orient. Recently, several groups have indeed devised innovative syntheses of
142
nanocrystals through which they have been able to group inorganic materials with
different properties in the same particle. These approaches are paving the way to the
development of nanosized objects able to perform multiple technological tasks. This talk
will review the recent advances in the synthesis of colloidal nanocrystals, with emphasis
on the strategies developed at NNL for the fabrication of colloidal nano-heterostructures,
as well as on their properties and the perspectives in this field.
A NOVEL ROUTE FOR NANOSTRUCTURED LUMINESCENT
NANOPARTICLES VIA Fe3+-CATALYZED OXIDATIVE
POLYMERIZATION IN AQUEOUS MEDIUM
Sun Jong Lee, Jung Min Lee, Yeon Jae Jung, and Dea Hyun Cho, Jung Hyun
Kim, Department of Chemical Engineering, Yonsei University, 134
Shinchon-dong, Sudaemoon-ku, Seoul 120-749, Republic of Korea ;
[email protected]
226
Unsubstituted thiophene can be polymerized by Fe3+-catalyzed oxidative polymerization
inside nano-sized thiophene monomer droplets, i.e., nano-reactors, dispersed in aqueous
medium, which can be performed under acidic solution conditions with anionic
surfactant. Besides, we proposed a synthetic mechanism for the formation of the
unsubstituted polythiophene nanoparticles in aqueous medium. This facile method
includes a FeCl3/H2O2 (catalyst/oxidant) combination system, which guarantees a high
conversion (ca. 99%) of thiophene monomers with only a trace of FeCl3. The average
particle size was ca. 30 nm, within a narrow particle size distribution (PDI = 1.15), which
resulted in a good dispersion state of the unsubstituted polythiophene nanoparticles. The
UV-visible absorption and photoluminescence (PL) spectrum were measured to
investigate the light emitting properties of the prepared unsubstituted polythiophene
nanoparticle emulsions. However, the luminescence efficiency of poly(thiophene)s in
solid state is relatively low. It becomes one of the most critical drawback for practical
applications. We introduced luminescent polythiophene shell-layer with 10 nm film
thickness onto the surfaces of monodisperse poly(styrene) nanoparticles to improve the
photoluminescence efficiency of poly(thiophene)s in the solid state. It was demonstrated
that core-shell poly(styrene/thiophene) latex particles were successfully prepared by Fe3+catalyzed oxidative polymerization with seeded emulsion polymerization. This method
provided a new synthetic route of core-shell type luminescent polymer particles with a
thin shell layer. The resulting latex particles showed that luminescence efficiency in the
solid state was better than that in the emulsion state due to the core-shell morphology
with a thin shell structure. This new strategy is universal for the synthesis of many other
materials or composite particles with controlled morphology. Finally, luminescent
poly(styrene) nanoparticles were prepared by Fe3+-catalyzed oxidative polymerization in
aqueous medium with heterogeneous emulsion phase. These poly(styrene) particles
showed various unique properties, i.e., low molecular weight, photoluminescence
properties, which were much different from the existing poly(styrene) polymer prepared
by conventional emulsion polymerization. The luminescent poly(styrene) particles may
have potential practical applications in various electrical and electro-optical devices,
especially in polymer light emitting diodes (PLEDs)..
143
PROTEIN SENSING USING NANOPARTICLE-FLUORESCENT
POLYMER COMPLEXES
Vincent M. Rotello,1 Uwe Bunz2 1Department of Chemistry, University of
Massachusetts, Amherst MA 01003 USA; 2 School of Chemistry and
BiochemistryGeorgia Institute of Technology, 901 Atlantic Drive, Atlanta,
GA 30332, USA; [email protected]
227
Most biomolecular recognition processes in biology occur via specific interactions.
Sensory processes such as taste and smell, however, use “differential” binding where the
receptors bind to their analytes by different binding characteristics that are selective
rather then specific. In our research, we are exploiting the tunability and size of polymers
and nanoparticles to provide sensors for biomacromolecules including proteins. In our
research, we have used nanoparticle-fluorescent polymer complexes to identify and
quantify proteins. where the nanoparticle surface provides the functional diversity
required for protein differentiation.. Ongoing research focuses on the use of these sensors
in biological fluids as well as their use to identify bacteria and other pathogens.
RESISTIVE CHEMICAL SENSORS FROM METAL OXIDE
NANOCRYSTALS SYNTHESIZED IN ORGANIC SOLVENTS
Nicola Pinna, Department of Chemistry and CICECO, University of Aveiro,
810-193 Aveiro, Portugal; [email protected]; and Giovanni Neri, Dept. of
Industrial Chemistry and Materials Engineering, University of Messina,
98166 Messina, Italy
228
Nowadays, chemical sensors find application in many technological fields, such as
environmental, industry, medicine, automotive, etc. Due to their simple structure and low
cost, Metal Oxide Semiconductor (MOS) resistive sensors represent the more
investigated typology. In order to enhance their performance, the synthesis of various
nanosized metal oxides has provided new impulse. Nanostructured materials are of
interest both for basic scientific research and technological applications as their
properties depend on their extremely large specific surface areas. Furthermore, their
surfaces have generally unique properties which greatly differ from those of bulk
materials. Because of the high surface-to-volume ratio, local phenomena such as
adsorption or modification of the electronic structure at the surface may contribute
significantly to the sensing properties of the materials. Here, we will introduce the
synthesis and characterization of representative metal oxides nanoparticles by nonaqueous sol-gel approaches leading to the preparation of nearly monodisperse and highly
crystalline nanoparticles. Their sensing properties and possible utilization in
technologically relevant devices will be presented.
144
FLUORESCENCE LABELING OF BIOLOGICAL CELLS AND
CREATING PROGRAMMABLE MATERIALS WITH
BIOFUNCTIONALIZED COLLOIDAL QUANTUM DOTS
Wolfgang J. Parak, Fachbereich Physik, Philipps Universität Marburg,
Renthof 7, 35037 Marburg, Germany; [email protected]
229
Two ideas for applications in which colloidal nanoparticles are used to interface cells are
discussed. For this the report will be structured in three parts. In the first part the colloidal
nanoparticles and in particular their surface chemistry will be discussed. In the second
part a nanoparticles based FRET system for the detection of intracellular ions will be
reported. In the third part an alternative system for the detection of intracellular ions
based on polymer capsules / nanoparticles based will be described. With a very general
procedure inorganic hydrophobic nanoparticles of different materials can be transferred
into aqueous solution by coating them with an amphiphilic polymer that is based on a
poly(maleic anhydride) backbone modified with alkylamine sidechains. Functional
groups with an amino anchor can be directly introduced in the polymer by reacting them
to anhydride groups of the backbone. This offers a very general route to water-soluble
nanoparticles of high colloidal stability, with good size distribution, and with a variety of
functional groups that are directly embedded in the polymer shell without the need of
post-bioconjugation. A FRET-pair based on colloidal quantum-dot donors and multiple
organic fluorophores as acceptors is reported. In contrast to similar systems which are
used as biosensors and detect specific changes of the donor/acceptor-distance under the
influence of analyte binding, our nanoparticle design seeks to optimize sensors that detect
spectral changes of the acceptor at fixed donor/acceptor distance. This approach allows
for relatively small acceptor-donor distances, and thus for high energy transfer
efficiencies, while simultaneously permitting high colloidal stability. The photophysics of
the system is characterized and compared to similar systems which have been reported in
literature. Polyelectrolyte microcapsules have been loaded with a pH sensitive, high
molecular weight SNARF-1-dextran conjugate. SNARF-1 exhibits a significant pHdependent emission shift from green to red fluorescence under acidic and basic
conditions, respectively. The spectral properties of the dye were found to be largely
retained after the encapsulation. Upon ingestion of SNARF-1-filled capsules by breast
cancer cells or fibroblasts, the pH change of the local capsule environment during
transition from the alkaline cell medium to the acidic endosomal/lysosomal
compartments could be observed. By incorporating magnetic and fluorescent colloidal
nanoparticles into the capsule-shell a novel type of multiplexed sensor system was
developed.
METAL NANOPARTICLE PLASMONS INTERACTING WITH CHIRAL
MOLECULES
Itai Lieberman, Gabriel Shemer, Tcipi Fried, Edward Kosower and Gil
Markovich, School of Chemistry, Tel Aviv University, Tel Aviv 69978,
Israel; [email protected]
230
145
Two issues related to silver nanoparticles interacting with chiral molecules will be
presented:
1. Colloidal Ag nanoparticles coated with L-glutathione attached to bimane
chromophores were studied by absorption, circular dichroism (CD) and fluorescence
spectroscopies. The absorption and CD were resonantly enhanced via Ag surface
plasmons by two orders of magnitude. The wavelength and particle size dependence of
the enhancement indicated that the electromagnetic "antenna" effect was in action, as
found in other surface enhanced optical phenomena.
2. The formation of chiral silver nanoparticles when deposited on DNA templates was
observed by CD spectroscopy. Several experimens designed to better understand the
mechanism leading to this effect will be presented.
RAPID DETECTION OF S-ADENOSYLHOMOCYSTEINE USING SELFASSEMBLED OPTICAL DIFFRACTION GRATINGS
Ghanashyam Acharya1, Chun-Li Chang1, David Holland2, Cagri Savran1 and
David H. Thompson2, Departments of Mechanical Engineering1 and
Chemistry2, Purdue University, West Lafayette, IN 47907, USA;
[email protected]
231
A self-assembled optical diffraction biosensor for the rapid detection of S-adenosyl
homocysteine (SAH), with a sensitivity limit of 24.5 pg/ml, has been developed. This
detection strategy uses homocysteine antibody-coupled magnetic microparticles to
capture SAH from solution and microcontact printed aptamer-functionalized
micropatterns specific for SAH on the surface of gold-coated glass slides. Based on these
specific interactions, SAH bound to the microparticles produces a self-assembled optical
diffraction grating upon exposure to the aptamer-functionalized micropatterns. A 39-mer
adenosine-specific aptamer sequence was chosen as the adenosine capture ligand for
SAH. The aptamer binds to SAH with high affinity (~5x10-8 M) and selectivity. A ωbiotin hexyl chain was coupled to the 5’ end of the adenosine aptamer for immobilization
onto streptavidin-saturated micropatterns. The aptamer-grafted micropatterns were then
used to capture SAH-bound microparticles.
MULTOCOLOR LIQUID CRYSTAL NANOPARTICLES AS EFFICIENT
FLUORESCENT REPORTERS IN BIOIMAGING AND BIOSENSORS
Jawad Naciri, Christopher M. Spillmann, George P. Anderson, Banahalli R.
Ratna, 4555 Overlook avenue, Naval Research Laboratory, Center For
Bio/Molecular Science & Engineering, Washington DC 20375, USA;
[email protected]
232
This work describes a process of preparing stable fluorescent polymeric liquid crystalline
nanoparticles (LCNs) using the miniemulsion polymerization technique. The
nanoparticles consist of dye molecules and polymerizable liquid crystals and surfactants.
146
The anisotropy generated by the liquid crystal molecules can be used to control the selforganization of dye molecules incorporated inside the nanoparticles, which is primarily
driven by π- π molecular orbital interactions. This self-organization corresponds to a
variable aggregation and is accompanied by a characteristic alteration of the fluorescence
spectra. The interaction between LC and dye molecules can promote or inhibit the
aggregation of dye molecules. By varying the dye concentration inside the nanoparticles,
emission signatures can be tuned to have the nanoparticles exhibit multiple colors using a
single excitation wavelength. Because of their small size, intense fluorescence with large
emission Stokes shift, and ease of bioconjugation, these nanoparticles may have broad
applications in biological labeling and imaging.
PLASMON-RESONANT NANORODS AS THERAGNOSTIC AGENTS
Ling Tong, Yan Zhao, Terry B. Huff, Matt N. Hansen, Ji-Xin Cheng, and
Alexander Wei, Department of Chemistry and Weldon School of Biomedical
Engineering, Purdue University, West Lafayette, IN 47907, USA;
[email protected]
233
Plasmon-resonant gold nanorods have been examined as multifunctional agents for
imaging and photoactivated therapies. Nanorods can be imaged with single-particle
sensitivity by two-photon luminescence (TPL) when excited by fs-pulsed laser
irradiation, and have been monitored in vivo while passing through blood vessels at
subpicomolar concentrations. TPL imaging can also be used to characterize the targeted
delivery of ligand-functionalized nanorods to tumor cells. Nanorods were coated with
oligoethyleneglycol (OEG) units using in situ dithiocarbamate formation, a novel and
robust method of surface functionalization. Nanorods coated with methyl-terminated
OEG chains were shielded from nonspecific cell uptake, whereas nanorods functionalized
with folate-terminated OEG chains accumulated on the surface of tumor cells
overexpressing their cognate receptor. Cells labeled with folate-functionalized nanorods
became highly susceptible to photothermolysis when irradiated at plasmon resonance,
often resulting in a dramatic blebbing of the cell membrane. The blebbing was
determined not to be directly caused by nanorod-mediated photothermolysis, but rather
due to the influx of extracellular Ca2+ following perforation of the cell membrane.
METAL NANOPARTICLES AND THEIR SENSING APPLICATIONS
Haining Wang and Shengli Zou, Department of Chemistry, University of
Central Florida, Orlando, FL 32816-2366, USA; [email protected]
234
Metal nanoparticles have been utilized for the development of sensors with high
sensitivities. We modeled the scattering and absorption spectra of single metal
nanoparticles with different structures and particles arranged in one or two dimensional
arrays. The objectives of the models focus on the simulations of the enhanced local
electric fields around nanoparticles for the surface enhanced Raman scattering and
narrow plasmon resonance peaks which may improve the sensitivity of chemical
147
detection. Enhanced local electric field |E|2 between two closely arranged nanoparticles
with an enhancement factor of 106 was obtained. Narrow extinction peaks with a width of
less than one nanometer are achieved in a one dimensional silver nanoparticle array.
Novel optical properties of metal particles with core shell structures will also be
discussed.
Session H2 – Keynote Paper
DEVELOPING TUMOR-TARGETED NANOTHERAPEUTICS ON
COLLOIDAL GOLD NANOPARTICLES
Giulio F. Paciotti1, Lonnie Myer1, Jay Friedman1, Doug Jones1, Shugeng
Cao2, Jielu Zhao2, David Kingston2, Lawrence Tamarkin1. 1CytImmune
Sciences, Inc., 9640 Medical Center Drive Rockville, MD 20850, USA;
[email protected]; 2Virginia Polytechnic Institute and State
University, Department of Chemistry, Blacksburg, VA 24061, USA;
[email protected]
235
Currently, first-line treatment of resectable solid tumors most commonly involves surgery
followed by a regimen of chemotherapy and/or radiation. Unfortunately this strategy
often fails because of recurrent or metastatic disease. To change this paradigm, new
cancer therapies must deliver multifaceted therapeutics to destroy the heterogeneous
population of tumor cells present within solid tumors prior to surgical removal. Our
approach to this problem has been to develop a multifunctional nanotherapeutic, termed
CYT-20000, that targets the delivery of two potent cancer therapies to solid tumors.
CYT-20000 consists to 27 nm particle of colloidal gold that is covalently bound with
tumor necrosis factor alpha, a paclitaxel prodrug and a thiolated form of PEG. Preclinical
data reveal that CYT-20000 significantly increases the circulatory half-life of paclitaxel,
albeit that the paclitaxel present in the circulation remains in a prodrug form.
Pharmacodynamic data reveal that CYT-20000 actively sequesters the paclitaxel prodrug
within the solid tumor and upon its arrival in the tumor the nanodrug generates paclitaxel
over an extended period of time. These data are consistent with ability of CYT-20000 to
induce a paclitaxel mediated anti-tumor response at significantly lower doses of drug. For
example CYT-20000 was 16 fold more effective than paclitaxel administration since 2.5
mg/kg of the nanodrug was as effective as 40 mg/kg of paclitaxel. Collectively the data
support that CYT-20000 not only targets the delivery of paclitaxel to solid tumors but
once inside the solid tumor milieu the nanodrug acts as a slow release depot that
generates paclitaxel over an extended period of time.
OPTIMIZATION OF NANOPARTICLE ARCHITECTURE FOR
ENCHANCED TARGETING IN DRUG DELIVERY
Matthew Hagy, Shihu Wang and Elena Dormidontova, Department of
Macromolecular Science and Engineering, Case Western Reserve University,
2100 Adelbert Road, Cleveland Ohio 44106; [email protected]
236
Targeting of polymeric nanoparticles is one of the major thrusts in modern drug/gene
delivery and nanoparticle architecture is one of the important factors influencing the
148
efficiency of targeting. We have applied Monte Carlo simulations to study the interaction
between the cell surface carrying mobile receptors and ligands tethered to a protecting
polymer layer covering a spherical or planar surface. We studied the effect of polymer
length, grafting density (aggregation number), degree of functionalization, ligand
architecture and valence on the efficiency of nanoparticle targeting for different energies
of ligand-receptor interactions and receptor densities of the cell surface. The efficiency of
targeting was estimated based on the (static) binding constant (free energy) and the
average binding for nanoparticle-receptor surface interactions. Based on the obtained
results we make predictions regarding the optimal design of a polymer-covered
nanoparticle to achieve either the maximal possible degree of binding to a receptor
surface, the maximum selectivity of binding or the most efficient use of ligands for a
given energy of ligand-receptor interactions and density of receptors on cell surface.
Binding constants and force-distance curves obtained from our simulations can be used to
analyze the results of experiments such as surface force microscopy.
DEVELOPMENT OF BORON NANOCAPSULES FOR NEUTRON
CAPTURE THERAPY
Kei Nakai1), Hiroyuki Nakamura2), Chunman Lee 3), Yasufumi Kaneda4) and
Akira Matsumura1), 1.Dept. of Neurosurgery, Institute of Clinical Medicine,
Univ. of Tsukuba, 1-1-1 Tennodai, Tsukuba,305-8575, Japan ;
[email protected] 2.Dept. of Chemistry, Gakushuin Univ. 3.Dept. of
Gastroenterological Surgery, Osaka Univ. 4.Division of Gene Therapy
Science, Osaka Univ.
237
Boron Neutron Capture Therapy (BNCT) is a tumor selective radiotherapy and clinical
trial is ongoing for malignant brain tumor patients. It based on the 10B[n,α]7Li nuclear
reaction. Tumor selective boron accumulation and neutron irradiation produces α particle
and 7Li ion. These high linear energy transfer particles afford tumor selective cell killing.
High accumulation and high tumor selective delivery of boron into the target tumor tissue
are the most important requirements to achieve efficient BNCT. We developed novel
boron delivery systems, one is fusion-mediated nano-particles based on HVJ-E drug
delivery system. The other is liposomal delivery system based on double-tailed closododecaborane lipids. We examined the boron accumulation to cancer cell line in vitro and
neutron irradiation experiments. Tumor bearing mice were used for bio-distribution
experiments with these new particles. Tumor-targeting-particles were also designed and
examined. As a result, boron concentration reached treatable range, which showed cell
killing effect in in vitro neutron irradiation experiments. Bio-distribution studies clarified
the time course of the liposomal boron delivery. Targeting molecule (transferrin,
hyaluronic acid) enhanced the tumor accumulation. Pilot study of the treatment
experiments is still undergoing but showing tumor disappearance in some subcutaneous
tumor-bearing mice. These results indicate that the current particles are potent vehicles
for boron delivery on BNCT.
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FORMATION OF DRUG PARTICLES OF CONTROLLABLE SIZE
USING SUPERCRITICAL CO2
Ram B. Gupta, Department of Chemical Engineering, Auburn University,
Auburn, AL 36849-5127, USA; [email protected]
238
Nanoparticles and microparticles offer unique properties that arise from their small size,
large surface area, and the interactions of phases at their interfaces, and are attractive for
their potential to improve performance of pharmaceuticals, neutraceuticals, and other
high-value-added materials. Over past two decades, supercritical carbon dioxide (above
31.1 oC and 73.7 bar) has emerged as a medium for the formation of micro- and nanoparticles of pharmaceutical compounds, due to the its adjustable solvent properties, high
diffusivity, non-flammability, and non-toxicity. Depending upon the solubility in
supercritical CO2, two classes of processes have emerged: (a) rapid expansion of
supercritical solution (RESS) for CO2 soluble materials, and (b) supercritical antisolvent
(SAS) for CO2-insoluble materials. In RESS process, the drug material is first dissolved
in supercritical CO2 and then expanded through a nozzle to rapidly precipitate as
particles. Since the expansion occurs as fast as the speed of sound, the material comes
out as small microparticles. But due to the limited solubility of drugs in supercritical
CO2, RESS process had limited utility, so far. In our recently developed RESS-SC
process [Industrial & Engineering Chemistry Research (2005), 44, 7380-7387] by using
menthol solid co-solvent, the solubility has been enhanced by several hundred fold. The
presence of the solid cosolvent also hinders the particle growth; hence the particles in
nanometer size range are easily obtained. Menthol is later removed by sublimation,
yielding pure drug nanoparticles. In SAS process, the drug material is first dissolved in an
organic solvent. The solution is then injected into supercritical CO2, resulting in the
extraction of solvent by supercritical CO2 and precipitation of the material. Since, the
speed of extraction is fast due to the high (gas-like) diffusivity of supercritical CO2, the
small microparticles of the material are obtained. We have further enhanced the
extraction speed by ultrasonic mixing which results in nanoparticles [US Patent
6,620,351; September 16, 2003]. In the new process, the particle size is easily controlled
by the extent of ultrasonic power supplied. The strong extraction ability of supercritical
CO2 allows the production of pure drug nanoparticles, free of any residual solvent or
additives.
PARTICULATE AEROSOLS FOR THE TREATMENT OF
RESPIRATORY INFECTIONS
Emily Thomas1, Stacy Sommerfeld1, Buffy Stohs2 and Jennifer Fiegel1,2,
1
Department of Chemical and Biochemical Engineering and 2Division of
Pharmaceutics, University of Iowa, Iowa City, IA 52242, USA; [email protected]
239
Bacterial respiratory infections such as tuberculosis, pseudomonas infections and
diphtheria, remain a major source of global morbidity and mortality. Despite the often
aggressive use of antibiotics, complete eradication of these infections is challenging,
indicating a need for new treatment approaches. To address this need, we are developing
150
new dry powder aerosols with an improved ability to target the delivery of antimicrobial
compounds to infected lungs. Dry powder aerosols containing antibiotics or antibacterial
proteins have been formulated via spray drying, utilizing L-leucine to improve powder
flow properties. Through experimental design, dry powders have been optimized for
high drug loading (>50%), preservation of antimicrobial activity, high dispersibility from
a simple hand-held inhaler and good aerodynamic properties to enable efficient
deposition within the respiratory tract (total estimated lung deposition > 30%).
NOVEL INHALATION DRUG POWDERS WITH CRYSTALLINE LLEUCINE COATING
Janne Raula, Anna Lähde, Esko I. Kauppinen; NanoMaterials Group,
Laboratory of Physics & Center for New Materials, Helsinki University of
Technology, P.O. Box 5100, FI-02150 TKK, Finland; Majid Naderi,
Manaswini Acharya; Surface Measurement Systems, 5 Wharfside Rosemont
Road, Alperton, London HA0 4PE United Kingdom; Jouko Lahtinen, Matti
Paajanen; Laboratory of Physics, Helsinki University of Technology,
P.O.Box 1100,FI-02015 TKK, Finland; [email protected]
240
Flowability and dispersibility of fine drug powders is very important in respiratory drug
delivery. Nowadays advanced delivery systems comprises carrier-free formulations
where fine drug particles are delivered without an aid of course carrier particles. We
present a novel method to simultaneously synthesize and surface-modify inhalable drug
particles in the gas phase using the amino acid, L-leucine. Upon vapor deposition on the
surface of salbutamol inhalable particles L-leucine form a coating of few nanometers
crystals. XPS studies proved a strong enrichment of L-leucine (> 90%) on the particle
surfaces. The coated fine powders perform good flowability and they can be fed via an
inhaler (Easyhaler®) without carriers. Emitted doses (ED) from the inhaler were relatively
high 5-7 mg/dose and their fine particles fractions (FPF) varied between 42-47%.
Dispersive surface energy agreed well with the dispersion in a way that energy decreased
while ED and FPF increased. Also, AFM studies showed that the force with the L-leucine
coated salbutamol particles was approximately 20% of that between the uncoated
particles. While uncoated particles strongly agglomerated, L-leucine coating protected
particles by preserving them against agglomeration under relative humidities up to 65 %.
Upon humidifying, salbutamol crystallized beneath the L-leucine coating.
INTEGRATED MOLECULAR TARGETING, IMAGING AND
SELECTIVE KILLING OF BREAST CANCER CELLS USING
NANOTUBES
Balaji Panchapakesan, Department of Electrical Engineering, University of
Delaware, Newark DE 19716, USA; [email protected]
241
Molecular targeting and photodynamic therapy have shown great potential for selective
cancer therapy. We hypothesized that monoclonal antibodies that are specific to the IGF1
151
receptor and HER2 cell surface antigens could be bound to single wall carbon nanotubes
(SWCNT) in order to concentrate SWCNT on breast cancer cells for specific nearinfrared phototherapy. SWCNT functionalized with HER2 and IGF1R specific antibodies
showed selective attachment to breast cancer cells compared to SWCNT functionalized
with non-specific antibodies. After the complexes were attached to specific cancer cells,
SWCNT were excited by 808 nm infrared photons at 800 mW cm−2 for 3 min.
Viability after phototherapy was determined by Trypan blue exclusion. Cells incubated
with SWCNT/non-specific antibody hybrids were still alive after photo-thermal treatment
due to the lack of SWNT binding to the cell membrane. All cancerous cells treated with
IGF1R and HER2 specific antibody/SWCNT hybrids and receiving infrared photons
showed cell death after the laser excitation. Quantitative analysis demonstrated that all
the cells treated with SWCNT/IGF1R and HER2 specific antibody complex were
completely destroyed, while more than 80% of the cells with SWCNT/non-specific
antibody hybrids remained alive. Following multi-component targeting of IGF1R and
HER2 surface receptors, integrated photo-thermal therapy in breast cancer cells led to the
complete destruction of cancer cells. Functionalizing SWCNT with antibodies in
combination with their intrinsic optical properties can therefore lead to a new class of
molecular delivery and cancer therapeutic systems.
MONODISPERSE MAGNETIC FERRITE/CARBON CORE-SHELL
NANOSTRUCTURES: FABRICATION AND APPLICATIONS
Xian-Wen Wei, Guo-Xing Zhu and Rui Ge, College of Chemistry and
Materials Science, Anhui Key Laboratory of Functional Molecular Solids,
Anhui Normal University, Wuhu 241000, P. R. China;
[email protected]
242
Nearly monodisperse core/shell nanostructures with porous magnetic ferrite core and
carbonaceous polysaccharide shells were prepared with a general and facile method.
Catalyst specimen such as noble metals can be anchored on the surface of as-obtained
core/shell nanostructures with a simple in-situ reduction technique without any foretreatment, which creates a ferrite magnetic microspheres/C/metal type of catalyst that
could be used for liquid phase reactions and showed an excellent catalytic property with
recoverable and reusable characters. The using of Fe3O4/C core/shell nanostructures as
carrier for targeted drug delivery was also explored. It was expected that these materials
may be applicable in targeted drug delivery, multiphase separation, and other organic and
inorganic nanocarriers in the future.
This work was supported by Science and Technological Fund of Anhui Province for
Outstanding Youth (No. 04046065), the National Natural Science Foundation (Nos.
20671002, 20490217, 20271002), the State Education Ministry (EYTP, SRF for ROCS,
SRFDP 20070370001) of P. R. China, and the Education Department ( No.
2006KJ006TD ) of Anhui Province.
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BACTERIA AND FUNGI AS TEMPLATES FOR SELF-ORGANISATION
OF GOLD NANOPARTICLES
Indrani Dakua, Alfredo Anceno, Oleg Shipin and Joydeep Dutta, Center of
Excellence in Nanotechnology, School of Engineering and Technology, Asian
Institute of Technology, 12120 Pathumthani, Thailand; [email protected]
243
Synthetic assemblies of nanometric metal particles into functional mesostructures for
possible applications were attempted via physico-chemical control approaches that has
proven to be challenging. Functional nanoparticles could assume rod, spherical or tubelike morphologies via dense assembly on surfaces of bacterial cells or fungal hyphae. The
assembled macrostructures with template species-dependent dimensions could be
employed as circuit or sensor components. Previous attempts on viral, bacterial, fungal or
diatom surface templated assembly of inorganic materials are based on considerably
complex chemistries involving proteins or DNA sequence recognition. More exotic
methods have been reported for the assembly of metal nanoparticles in wire-like form,
based on biological templates. Here we will report a simple, physiologically driven
process where nutrient utilization serves as an essential driver of nanoparticle
organization on living filamentous fungi and also our ongoing work on the assembly of
chitosan-coated or glutamate-stabilized gold nanoparticles on living bacterial and yeast
templates in nutrient rich versus nutrient poor milieu.
SYNTHESIS, SELF-ASSEMBLY AND FIELD-RESPONSIVE OPTICAL
DIFFRACTIONS OF SUPERPARAMAGNETIC COLLOIDS
Yadong Yin, Department of Chemistry, University of California, Riverside,
92521 USA; [email protected]
In this presentation we report the rational synthesis, self-assembly and field-responsive
optical diffractions of monodisperse colloidal nanocrystal clusters (CNCs) of magnetite
with tunable sizes from ~30 to ~180 nm. These CNCs are prepared through a hightemperature hydrolysis process using polyelectrolyte as a surfactant. Each cluster is a
three-dimensional aggregate of many single magnetite crystallites of ~10 nm, thus
retaining the superparamagnetic properties at room temperature. The CNCs show strong
responses to external magnetic field due to their much higher magnetization per particle
than that of individual magnetite nanodots. The use of polyelectrolyte as surfactant in
synthesis provides the colloids highly charged surfaces. The combination of
superparamagnetic property, high magnetization per particle, monodispersity, and highly
charged surfaces allows the CNCs self-assemble into three-dimensional ordered lattices
in solution in response to an external magnetic field. Such colloidal lattices diffract light
with wavelength magnetically tunable in the entire visible spectrum, and the optical
response to the external magnetic field is rapid and fully reversible.
244
TUNABLE GEL FILMS OF SINGLE DOMAIN COLLOIDAL PHOTONIC
CRYSTALS
Tsutomu Sawada, National Institute for Materials Science, Tsukuba, Ibaraki
245
153
305-0044, JAPAN; [email protected]
Colloidal crystals may be classified into two types; loosely packed colloidal crystals and
tightly packed ones. The latter is often called synthetic opal and is drawing much
attention especially as a template for making an inverse opal structure that can be a
photonic crystal with a full band-gap if composed with sufficiently high dielectric
constant material. With the loosely packed system, however, if its structure is
immobilized in a polymer gel, we can obtain a highly tunable photonic crystal because of
the extra space among particles, which is also a very attractive feature. The loosely
packed colloidal crystal is usually formed in a system where like-charged particles are
suspended in the liquid medium. In such a system, there seems to be a high possibility of
forming large single crystals, which is desired in practical applications, due to strong,
long-range interparticle interaction. In this presentation, I will show preparation of a
large single-domain colloidal crystal, immobilization of the crystalline structure by
gelation with preserving the crystalline quality, and tunable characteristics of the obtained
gelled crystals.
SHEAR-ALIGNED ASSMEBLY OF COLLOIDAL PHOTONIC CRYSTAL
Chih-Hung Sun and Peng Jiang, Department of Chemical Engineering,
University of Florida, Gainesville, FL 32611, USA; [email protected]
246
A versatile spin-coating technique for assembling wafer-scale colloidal photonic crystals,
along with a large variety of functional nanostructured materials has been developed. The
methodology is based on shear-aligning concentrated colloidal suspensions using
standard spin-coating equipment. It enables large-scale production of both 3D and 2D
non-close-packed colloidal crystals as well as a wide range of nanostructured materials
including 3D ordered polymer nanocomposites, macroporous polymers, nanohole arrays,
metallic surface gratings, attoliter microvial arrays, 2D magnetic nanodots, metallic
pyramid arrays, and more. The spin-coating platform is compatible with standard
semiconductor microfabrication, enabling parallel production of micropatterns for
potential device applications. The spin-coating process also provides a new route to study
the fundamental aspects of shear-induced crystallization, melting and relaxation.
Different from simple shear flows in conventional shear cells, the flow in the spin-coating
process is inherently non-uniform. The application of assembled periodic nanostructures
as surface-enhanced Raman scattering (SERS) substrates will also be discussed.
ARRAY OF NON-LINEAR DIELECTRIC NANO-CRYSTALS
S. Berger, Faculty of Materials Science and Engineering, Technion, Israel;
[email protected]
247
Growth and properties of non-linear dielectric nano-crystals arranged in a high density
array structure will be presented. The fabrication mechanism consists of three stages:
formation of a high density array of alumina pores by electrochemical anodization of thin
154
aluminum film, insertion of a liquid solution into the pores, reducing the temperature of
the liquid solution to the saturation point, nucleation from the saturated liquid solution
and growth of single crystals. The density of the pores is in the range of 1010 cm-2. The
average diameter of the crystals is varied from 10nm to 90nm by changing the applied
electric field. The length of the crystals is also controllable by the length of the pores
(1μm and 0.3μm lengths are demonstrated). Various non-linear dielectric nano-crystals
were grown inside the pores such as Tri-Glytcine Sulphate (TGS), Sodium potassium
double tartrate hydrate known as Rochelle salt (RS), potassium nitrate (PN) and
potassium niobate (PNB). The crystals were grown with a preferred crystallographic
orientation along the longitudinal axis of the pores. The RS nano-crystals in the pores
have ferroelectric behavior with enhanced remnant polarization, coercive field and Curie
temperature relative to bulk-size RS crystals. In the case of TGS nano-crystals in the
pores, pyroelectric behavior is recorded for the first time for such small crystals. In the
case of KNO3 nano-crystals in the pores, an induced electric field transition from
paraelectric to ferroelectric behavior was found for the first time and does not occur
under the same conditions in bulk-size crystals. These examples, which will be presented,
demonstrate the unique non-linear dielectric behavior of the nano-crystals grown inside
the alumina pores. The conditions for nucleation and growth of single crystals inside the
pores are modeled and will be presented based on geometrical and free energy
parameters.
DNA ASSISTED ASSEMBLY OF LINEAR NANOPARTICLE ARRAYS
ON CARBON NANOTUBES
Zhaoxiang Deng, Yulin Li and Xiaogang Han, Department of Chemistry,
University of Science and Technology of China, Hefei, Anhui 230026, China;
[email protected]
248
Engineered DNA nanostructures have been successfully employed to scaffold the
assembly of gold nanoparticles (AuNPs) into well-defined 2D lattices as well as micronlong linear arrays. Although DNA represents an outstandingly ideal template for
programmed assembly of materials, the flexibility of the structures it forms often causes
problems such as curling, self-entangling and even self-crosslinking when used to
assemble multivalent objects. In sharp contrast to DNA molecules, single walled carbon
nanotube (SWNT) with diameter down to several nanometers still has very high native
rigidity that should make it well suited as a counterpart to DNA for assembling
nanoscaled objects. Here we report a strategy toward the assembly of AuNPs onto DNAwrapped SWNTs. Wrapping of d(GT)n-SH DNA strands results in multiple thiol groups
on the surfaces of carbon nanotubes. The assembly of gold nanoparticles to carbon
nanotubes is then driven by gold-thiol bonding. Agarose gel electrophoresis is then used
to purify the conjugates. Alternatively, we will also demonstrate that gold nanoparticles
can be assembled onto carbon nanotubes by hybridizing the DNA complements attached
on gold nanoparticles with those appended on carbon nanotubes, resulting in a selfassembly strategy with even more versatile controls. The success in assembling AuNPs
onto SWNTs paves a way for further decorations of the nanogolds assembled on carbon
nanotubes in order to achieve multi-functionalities. The strategy we have developed in
155
this work does not require any chemical modifications to the sidewalls of carbon
nanotubes in order to introduce special chemical groups for the assembly. The resulted
nanoparticle-SWNT conjugates are expected to find important applications in catalysis,
nanoscale electronics as well as novel sensors.
MANUFACTURING OF MULTIFUNCTIONAL NANOPARTICLES
Heinrich Hofmann, Jatuporn Salaklang and Alke Petri-Fink; Institute of
Material, Powder Technology laboratory, Ecole Polytechnique Fédérale de
Lausanne, Lausanne, Switzerland, [email protected]
249
Nanoparticles for biomedical or electronic devises like gas sensors ha to fulfil several
needs of physical, chemical and biological origin. Particles with superparamagnetic
behaviour , showing also fluorescenc and a very specific adsorption to organelles is one
of the recent examples. It is evident that such particles has to show a very high colloidal
stability even in comblex liquids like blood serum. To fulfil all these conditions,
composite articles or beads with different nanosized particles like maghemite and
manganese doped ZnS in a polymer or silica matric were manufactured. The surface was
modified with several peptides and proteins whereas the paptide synthesis were carried
out at the surface of the particles. The challang in the fabrication of such particles is the
change of solveant, pH and ionic strength especially during during the coating step. To
fulfil biological needs , the whole particle has to show a diameter < 100nm. We have
developed a fixed bed reactor using the advadage that the core of the particles is made
with superparamagnetic iron oxide. The particles are fixed in a strong quadropole
magnetic field gradient which prevents agglomerationof the particle even we pass the
point of zero charge several times during the coating.. Additionally to the improved
quality, we have a much higher out put and better efficacy of peptide coating. An
interesting application in the biomarker separation with such particles will be showed.
CHEMOMECHANICAL SURFACE MODIFICATION OF INORGANIC
NANOPARTICLES
S. Pilotek, S. Schär, K. Steingröver, F. Tabellion, Buhler Inc., Dept.
PARTEC, Austin, TX 78701, USA; [email protected]
250
Inorganic Nanoparticles can be understood as carriers of functions and as such they are
interesting for the use in functional materials. Examples for functions are UV absorption,
photocatalytic activity, mechanical stability or surface structure. However, using
nanoparticle powders, intorduction of particles into the matrix materials on the nanoscale
is challenging and needs special attention. For practical applications, inorganic
nanoparticles are needed in a well-dispersed state that is stable with respect to
downstream processes like mixing, formulating, casting, coating, or molding. Surface
modification enables manufacturing nanoparticle dispersions that fulfil the list of
requirements. Using surface modification, nanoparticles can be stabilized in different
media such as water or organic solvents. We propose a chemomechanical process in
which starting from agglomerated nanopowders a surface modification reaction is carried
156
out under well-defined mechanical stress. We used high-energy agitator bead mills to
provide the shear forces. This equipment is advantageous because it provides a wide
parameter space for optimization like energy input, bead size and product flow velocity in
addition to being easily scaleable. For stabilizing nanoparticles, the surface needs to be
adjusted to the respective medium. We were able to disperse nanoscaled zincoxide in a
series of diverse organic solvents such as ethanol, xylene, and butylacetate. As another
example, chemomechanical processing yielded dispersions of photocatalytical titania in
both water and xylene from commercial grade nanoscaled TiO2. As a step beyond
stabilization, molecular surface modification makes surface functionalization of
nanoparticles feasible. Functionalization may comprise the grafting of polymerizable
groups or the control of IEP/ particle charge of a system. Using a surface modification
with acrylic groups, we were able to introduce high percentages of pyrogenic silica into a
radiation-curable acrylic matrix to improve mechanical properties. As another example,
modification of pyrogenic silica with aminosilanes lead to cationically stabilized aqueous
silica dispersions of low viscosity. Such systems may be applicable for the improvement
of ink-jet printability of paper. As a summary, we present chemomechanical processing
of inorganic nanoparticles into dispersions in water, organic solvents, and resins made by
combining chemical and mechanical means.
ELECTRON-INDUCED SURFACE MODIFICATION: PHYSICS AND
TECHNOLOGY
Gil Rosenman, School of Electrical Engineering-Physical Electronics, Tel
Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel, [email protected]
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The major trends in modern microelectronic, optical, chemical, pharmacological, biomedical and other material-based processing technology are based on development of
smart particles with modified physico-chemical-biological interface for variation of its
fundamental properties. The developed technologies mainly apply diverse methods
changing chemical identity of their surfaces by means of intermediate layers of different
chemical origin which modify original surface energy and its related properties. We
developed a new approach to design functional physico-chemical interface of solid state
materials and applied it to micro- and nanoparticles for modification of their surface free
energy and related properties (adsorption, adhesion, wettability, etc) with nanoscale
resolution. This new patented concept is based on defect free electron-induced surface
energy modification created by low energy electron irradiation. The electron current and
energy of the electron beam in this method are co-adapted to micro- and nanoparticles
sizes, electron/hole traps structure and their space distribution. The main advantages of
the method are as follows: a. deep and gradual tuning of the tailored surface energy and
related properties (adsorption, adhesion, wettability, etc) in a wide range b. tailoring the
modified surface energy and related properties on unlimited material surface area or on
micro- and nanoparticles c. complete reversibility of the modified surface energy and its
related properties d. compatibility of the developed method with well-known techniques
widely used in modern technology. The studies were conducted with different sorts of
materials including, Si-based materials, dielectric amorphous (glass, polymers)
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crystalline and ceramic oxide materials (mica, alumina, titanium oxide, zinc oxide,
calcium carbonate, etc), some of metals (Ti, Al, Cu) and as well biomimetic materials
(hydroxyapatite, hydrogels, calcium phosphates, sea shells, etc) and applied to micro- and
nanoparticles. We present the results of wide experimental and theoretical research of the
observed phenomenon in representative material SiO2 as well in micro- and nanopaticles
of different origin TiO2, ZnO2, Hydroxyapatite and L-ascorbate for surface modification
and variation of their key physical and technological properties.
THE USE OF SUPERCRITICAL CO2 FOR CONDUCTING SILANE
REACTIONS ON SURFACES
Carl P. Tripp, Laboratory for Surface Science and Technology (LASST) and
Department of Chemistry, University of Maine, Orono, ME 04469, USA;
[email protected]
252
There are many attractions to using supercritical CO2 as a solvent when conducting
surface reactions on silica. In addition to being an environmentally benign solvent, the
supercritical CO2 has the unique ability to remove the water layer on silica. Moreover,
reactions conducted in supercritical CO2 occur in regions of the surface that are not
accessible with conventional solution or gaseous treatment protocols. Supercritical CO2
has the additional advantage of simple solvent separation through venting and when
removed, there is no “caking” of the silica powder. However, some of these advantages
are not realized for silane reactions conducted on other oxides such as titania and
alumina. In this presentation, I will provide several examples of the use of supercritical
CO2 for conducting reactions on silica and metal oxides. Examples include traditional
silane chemistries as well as Atomic Layer Deposition with porous materials.
Comparison to conventional solution and gas phase reactions will be provided in order to
highlight the advantages and limitations of this solvent system.
ADVANCES IN PROTEIN MIMICS USING PEPTIDE-COATED
NANOPARTICLES
Brian Turner, R. Gerald Keil, Scott Miller, Leslie Hiatt, Ryan Rutledge,
David Wright, and David E. Cliffel, Department of Chemistry, Vanderbilt
University, Nashville, TN 37235-1822, USA; [email protected]
253
The ability to easily functionalize gold nanoparticles with peptides extending from the
surface allows us to mimic the types of biomacromolecular recognition structures
important in antigen-antibody interactions. Our initial successes demonstrated that
surface modified gold clusters using peptide epitopes from hemagglutinin and anthrax
protective antigen proteins would be specifically recognized by monoclonal antibodies
for these proteins. Our additional work has explored the mapping of protein sequences of
Ebola glycoproteins to identify the epitopes for specific antibodies by presenting it on a
gold nanocluster. We have also developed a nanoparticle mimic for the fusion protein of
the respiratory syncytial virus (RSV). The ability to multi-functionalize molecular
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recognition structures was demonstrated by showing that epitope recognition is
orthogonal for two different peptide epitopes put on the same nanoparticle. Current work
explores the NIR fluorescence of peptide-linked gold and platinum nanoparticles using
the ability to cleave the linkage to control emission intensity.
SELF-ASSEMBLED NANOSTRUCTURES VIA NANOPARTICLE
SURFACE FUNCTIONALIZATION
Ronald L Cook and Darrin Miller TDA Research, Inc. 4663 Table Mountain
Drive Golden CO 80403, USA; [email protected]
254
Mesoporous materials are materials having pores with diameters larger than 2 nm and
smaller than 50 nm. Although mesoporous oxides have been prepared from many
materials (e.g. alkoxides of niobium, tantalum, titanium, zirconium, cerium and tin) the
bulk of reported mesoporous materials are prepared using silicon and aluminum
alkoxides. Although zeolites (e.g. microporous materials, pores <2nm) are widely
utilized in adsorption, separation technologies and catalysis, there is an ever increasing
demand for new, highly stable well defined mesoporous materials because of the need for
ever higher accessible surface areas and pore volumes for chemical processes involving
larger and more complex molecules. The majority of zeolites and mesoporous materials
(e.g. M41S , MCM-41, MCM-48, MSU-B, etc.) are synthesized using bottom up methods
with organic templates. The mesoporous structure is formed around and in a sense
directed by the geometry of the template. In this presentation we will discuss the
synthesis of stable, crystalline mesoporous alumina materials using surfacefunctionalized boehmite nanoparticles as precursors. Reactions between the surfacefunctionalized boehmite nanoparticles via a self assembly reaction give rise to structured
mesoporous alumina materials.
GROWTH MECHANISM, STRUCTURAL REGULATION AND
FUNCTIONALIZATION OF CARBON-BASED NANOTUBES
Zheng Hu, Key Laboratory of Mesoscopic Chemistry, School of Chemistry
and Chemical Engineering, Nanjing University, Nanjing 210093, China;
[email protected]
255
The growth mechanism is a long-standing and controversial issue in the CNT-related
studies and has become a choke point for the development of this field. By using the in
situ thermal analysis-mass spectroscopic technique, the CVD growth process of CNTs
with benzene precursor has been clearly illuminated and the six-membered-ring-based
growth mechanism through surface diffusion is deduced. Along this line, a synergism
mechanism of C5N-six-membered-ring-based growth through surface diffusion and
vapor-liquid-solid growth through bulk diffusion was further inferred for the synthesis of
CNx nanotubes from pyridine precursor. Accordingly, the nitrogen content in CNx
nanotubes has been regulated within 3~8% and the so-synthesized CNx nanotubes have
quite uniform distribution of the nitrogen species which is beneficial for the surface
functionalization. The platinum nanoparticles were then conveniently immobilized on the
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CNx nanotubes due to the N-participation which shows promising electrocatalytic
property for methanol oxidation.
Session L1 – Keynote Paper
POLYMER VESICLES WITH HIGHLY SEWLECTIVE PERMEABILITY
M. Kumar, M. Grzelakowski and W. Meier, Department of Chemistry,
University of Basel, Klingelbergstr. 80, 4056 Basel, Switzerland;
[email protected]
256
The permeability and solute transport characteristics of amphiphilic triblock-polymer
vesicles containing the bacterial water-channel protein Aquaporin Z (AqpZ) were
investigated. The vesicles were made of a block copolymer with symmetric poly-(2methyloxazoline)-poly-(dimethylsiloxane)-poly-(2-methyloxazoline) (PMOXA15PDMS110-PMOXA15) repeat units. Light scattering measurements on pure polymer
vesicles subject to an outwardly-directed salt gradient in a stopped flow apparatus
indicated that the polymer vesicles were highly impermeable. However, a large
enhancement in water productivity (permeability per unit driving force) of up to ~800
times that of pure polymer was observed when AqpZ was incorporated. The activation
energy (Ea) of water transport for the protein-polymer vesicles (3.4 kcal/mol)
corresponded to that reported for water-channel-mediated water transport in lipid
membranes. The solute reflection coefficients of glucose, glycerol, salt and urea were
also calculated, and indicated that these solutes are completely rejected. The productivity
of AqpZ-incorporated polymer membranes was at least an order of magnitude larger than
values for existing salt-rejecting polymeric membranes. The approach followed here may
lead to more productive and sustainable water treatment membranes, while the variable
levels of permeability obtained with different concentrations of AqpZ may provide a key
property for drug delivery application
Session L1 – Contributed Paper
NOVEL FORMATION OF NANO-LIPOSOMES ENCAPSULATING A
HYDROPHILIC DRUG SIMULANT IN A CONTINUOUS FLOW
MICROFLUIDIC SYSTEM
Andreas Jahn1,3, Joseph E. Reiner1, Wyatt N. Vreeland2, Don DeVoe3,
Laurie E. Locascio2, Michael Gaitan1, 1NIST, Semiconductor Electronics
Division, EEEL, Gaithersburg, MD 20899 USA; 2NIST, Biochemical Science
Division, CSTL, Gaithersburg, MD 20899 USA; 3University of Maryland,
Biomedical Engineering, College Park, MD 2001 USA;
[email protected]
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A facile method to tailor the size and size distribution of nanometer scale liposomes in a
continuous-flow microfluidic design is presented. Encapsulation of a model drug into the
liposomes is analyzed with Fluorescence Fluctuation Spectroscopy (FFS); and results
show that this system allows for control of encapsulation efficiency as well as
minimization of encapsulant consumption. A stream of lipids dissolved in isopropyl
alcohol is hydrodynamically focused and sheathed between two oblique aqueous buffer
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streams in a microfluidic channel. The laminar flow in the microfluidic channel enables
controlled diffusive mixing at the liquid interfaces causing the lipids to become insoluble
and self-assemble into vesicles. While in traditional bulk mixing techniques individual
fluid elements experience uncontrolled mass transfer profiles and mechanical stresses;
microfluidics enable precise and reproducible control of the flow conditions, hence
reproducible fluidic mixing on the micrometer length scale is possible. This
reproducibility allows for adjustment of the lipid self-assembly and the resultant
liposome size and size dispersion. Using this technique, the liposome size is tunable over
a mean diameter of 50 nm to 150 nm by adjusting the ratio of the alcohol-to-aqueous
volumetric flow rate. For drug delivery applications, the encapsulation efficiency needs
to be controlled as well; further minimizing the waste of the encapsulant that is not
entrapped into the interior aqueous space of the liposome is desirable. In contrast to
conventional mixing techniques where liposomes are formed in a bulk aqueous solution
containing a homogenous concentration of the water-soluble encapsulant, this technique
can confine the encapsulant to the immediate vicinity where lipids self-assemble into
liposomes. The precise spatial localization of the encapsulant solely to the region of
liposome formation allows for greatly reduced sample consumption without adversely
affecting the liposome encapsulation efficiency. Size and size dispersion is determined
with tandem Asymmetric Flow Flow Field Fractionation (AF4), Multi-Angle Laser Light
Scattering (MALLS), and Dynamic Light Scattering (DLS). Analysis of the first two
moments of the photon probability distribution function with FFS in combination with
Fluorescence Correlation Spectroscopy (FCS) enables us to determine the encapsulation
efficiency from the brightness of the liposomes. The liposome self-assembly strategy
described here is amenable to drug encapsulation at the point of care, potentially enabling
liposome-mediated drug delivery that is not limited by shelf life of the liposome
preparation.
SIZE ANALYSIS OF LIPOSOMES BY BOTH PHOTON CORRELATION
SPECTROSCOPY (PCS) AND ASYMMETRIC FLOW FIELD-FLOW
FRACTIONATION (AF4)
Stefan Hupfeld, Martin Brandl, Department of Pharmacy, University of
Tromsø, N-9037 Tromsø, Norway, [email protected]
258
Liposomes have gained importance as versatile carriers for drugs. Depending on the
preparation method their size may range from a few nanometers up to several
micrometers. Size and size distribution are key characteristics of liposomes which affect
not only their loading capacity and colloidal stability, but also their in vivo behavior like
clearance from the blood stream and biodistribution. For successful targeting to solid
tumors and inflamed tissue, small to intermediate sizes and good size homogeneity are
required. Common size analysis techniques for liposomes comprise mainly photon
correlation spectroscopy (PCS) besides various electron microscopic approaches. Recent
reports emphasize that PCS alone may be insufficient in terms of resolving more
heterogeneous size distributions. Asymmetric flow field-flow fractionation (AF4)
features the fractionation of macromolecular to nano-particulate samples according to
their diffusion coefficient / size. In our case AF4 was combined with online multi-angle
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light scattering detection (AF4-MALS). The aim of this study was to compare size
distributions obtained from PCS and AF4-MALS of a liposome sample prepared by
extrusion through 30 nm-pore filters. The liposomes were made from egg
phosphatidylcholine (Lipoid E80) by consecutive extrusion through filters with
decreasing pore sizes down to 30 nm using a custom-made continuous high-pressure
filter extruder. The resulting liposome sample was then analyzed by both photon
correlation spectroscopy (PCS), using Nicomp 370 (Particle Sizing Systems, Santa
Barbara, CA), and AF4-MALS (Wyatt Technology Corp, Santa Barbara, CA). The AF4
consisted of a thin trapezoidal channel where a cross-flow was applied perpendicular onto
a horizontal channel-flow (Eclipse 2, Wyatt Technology Europe GmbH, Dernbach,
Germany). The detectors were an 18-angle MALS-detector (Wyatt Technology Corp) for
size determination, and a single wavelength UV detector G1314A (Agilent Technologies
Inc, Santa Clara, CA) and differential refractive index detector Optilab rEX (Wyatt
Technology Corp) for concentration detection. The particle size of the liposomes was
calculated using the Astra software (Wyatt Technology Corp) applying the “coated
sphere model”. An AF4-method was developed having a channel height of 250 µm, a
channel-flow of 1 ml/min and a cross-flow gradient decreasing from 2.0 to 0.15 ml/min
over 30 minutes. This method provided both elution of the liposome sample within
reasonable time and good separation of the sample. Size determination by AF4-MALS
yielded a mean geometric radius that corresponds well with the mean hydrodynamic
radius obtained by PCS using a Gaussian distribution fit. Both PCS and AF4-MALS
represent thus good alternatives for size determination of small and homogeneous
liposomes. However, fractionating the sample and subsequent online size and
concentration determination by AF4-MALS gives a more detailed insight into the size
distribution.
Session L1 – Keynote Paper
VECTORIAL TRANSPLANTATION OF PHI29 GP10 CONNECTOR
PROTEIN INTO C20BAS LIPOSOME MEMBRANES
Jong-Mok Kim and David H. Thompson, Department of Chemistry, Purdue
University, West Lafayette, IN 47907, USA; [email protected]
259
The incorporation of DNA packaging motors into liposome membranes offers the
promise of combining the positive features of viral and non-viral gene delivery by
mimicking a positive attribute of viral function (i.e., controlled packaging of DNA) using
a liposome composition that has a favorable safety profile and low immunogenicity. This
contribution describes our effort to incorporate the gp10 motor protein connector of phi29
phage into a host liposome membrane. Since the band of hydrophobic residues in the
connector that contacts the viral capsid is approximately 2 nm, it is too small to be
incorporated within a conventional liposome bilayer membrane. We have chosen the
eicosanyl-based bolalipid, C20BAS, as the host membrane for gp10 connector because it
has a hydrophobic thickness that is compatible with the protein. Vectorial orientation of
the connector within C20BAS liposomes was promoted using Ni2+:NTA-PEG600modified glass surfaces to capture N-terminal his-tag connectors prior to proteoliposome
reconstitution. Confocal fluorescence, AFM and TEM data suggests that the phi29 gp10
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connector is liposome-associated and that the liposomes can be detached from the surface
after gp10 insertion by the addition of excess imidazole.
Session L1 – Invited Paper
LYOPHILISOMES: A NEW TYPE OF (BIO)CAPSULES
Willeke WF Daamen, Paul P. J. Geutjes and Toin TH van Kuppevelt,
Department of Biochemistry 280, Radboud University Nijmegen Medical
Centre, Nijmegen, 6525 GA, The Netherlands; [email protected]
260
A number of techniques have been explored to prepare hollow structures (capsules). For
biological and biomedical applications, biocompatibility and biodegradability are major
issues. It would be an advantage if bioactive molecules could easily be incorporated in
capsule wall and/or lumen, creating high potency in the field of e.g. (targeted) drug or
nutriceutical delivery. We here report a general methodology that enables the preparation
of a novel class of nano- to microscale capsules ("lyophilisomes") using a combined
freezing, annealing and lyophilization procedure. Elastin was used as a model system, but
the methodology works equally well with other bio(macro)molecules. Solubilised elastin
was obtained from purified elastin fibres. Capsules were prepared by quench freezing an
elastin-acetic acid solution in liquid nitrogen, followed by annealing and lyophilisation
according a standardised procedure. The morphology of the capsules was analysed by
scanning and transmission electron microscopy. Capsules were sorted using fluorescence
activated cell sorting (FACS). Fluorescent probes, enzymes or antibodies were
incorporated in the capsule wall by addition to elastin solution prior freezing and
lyophilization. To load the lumen of the capsules, the capsules were crosslinked for 24 h
and incubated with probes, enzymes or antibodies for 96 h. The in vitro release was
assessed after incubation with the enzyme elastase. Capsules ranged from 200 nm - 10
μm and could be separated on basis of size by FACS. Fluorescent-labeled
(macro)molecules could be differentially incorporated in the capsule wall and lumen and
were released by elastase digestion. Capsules could also be prepared from other proteins
(serum albumin and atelocollagen) and from sugars (e.g. heparin). The methodology
comprises three phases: micro-phase separation by fast freezing in liquid nitrogen,
structural rearrangement by annealing and the creation of a lumen by lyophilisation, most
likely according to a 3D analogy of the coffee stain principle. Capsule formation does not
rely on amphiphilicity of the molecules used, but is based on physical rather then
chemical principles. Molecules of interest could be differentially incorporated in and
subsequently released from the lumen and/or wall of the capsules and may thus have
potential as a binary delivery and release system. Using this technology, a wide range of
new (bioactive) capsules may be anticipated. This methodology may fuel new
developments in a large number of areas including food industry, agriculture,
pharmacology and medicine.
EQUILIBRIUM AND NON-EQUILIBRIUM STRUCTURE OF LIQUID
CRYSTAL NANOPARTICLES
Ben J. Boyd1, Yao-Da Dong1, Shakila Rizwan2, Sarah Hook2, Michael
Rappolt3, Heinz Amenitsch3, Thomas Rades2. 1 Monash Institute
261
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Pharmaceutical Science, Monash University, Parkville, Australia; 2 School of
Pharmacy, University of Otago, Dunedin, New Zealand; 3 Institute of
Biophysics and Nanosystems Research (IBN), Austrian Academy of
Sciences, Graz, Austria; [email protected]
Nanostructured liquid crystalline particles, such as cubosomes and hexosomes, are
gaining increasing interest for potential application in fields such as drug and agricultural
delivery. Their internal nanostructure commonly reflects the liquid crystalline structure of
the parent non-dispersed mesophase. Whilst the equilibrium internal structure of these
particles has been well characterised using small x-ray scattering (SAXS), the surface
structure and morphology of the particles, and the responsiveness of the internal structure
to external changes in conditions has received little attention, despite their obvious
implications for application. We have recently investigated the morphology of
cubosomes and hexosomes using cryo-FESEM, which permits a three dimensional image
of particles in the sublimation plane, providing an important advance on two dimensional
cryo-TEM for investigating these particles. We have found that the surface structure of
cubosomes and hexosomes appear quite different. The cubosome particles exhibit a
nodular surface structure, consistent with fractured non-dispersed parent phase, whereas
hexosome particles appear to have a smoother surface structure. Furthermore, previous
reports that hexosomes are best represented by flat hexagonal prisms is challenged by the
finding of particles whose morphology is best described by a squat cylinder capped by
two cones, much like a ‘spinning top’. The finding has implications for the use of these
particles where particle adhesion to surfaces is crucial to their performance, such as in
agricultural delivery. The above results also indicate that the internal nanostructure of the
particles has important implications for the surface structure and hence performance of
the particles. The non-equilibrium internal nanostructure of cubosomes and hexosomes
has been studied using synchrotron SAXS and significant differences have been observed
on cooling liquid crystalline dispersions through equilibrium phase boundaries. Not only
was supercooling of liquid crystalline particles by up to 40ºC observed, but the formation
of phase structures not present on heating (such as the gyroid cubic phase only present at
low water content in non-dispersed systems, but never in dispersions) was also found.
Together these results represent advances towards a better understanding of both the
internal and surface properties of liquid crystalline particles, of value for the development
of these particles for delivery applications.
NANOPARTICLE BASED IONIC MATERIAL
Emmanuel P. Giannelis, Department of Materials Science and Engineering,
Cornell University, Ithaca, NY 14853, USA; [email protected]
262
Nanoparticle-based ionic materials (NIMS) are hybrid particles comprised of a charged
oligomeric corona attached to hard, inorganic nanoparticle cores. Because of their hybrid
nature, physical properties –rheological, optical, electrical, thermal - of NIMS can be
tailored over an unusually wide range by varying geometric and chemical characteristics
of the core and canopy and thermodynamic variables such as temperature and volume
fraction. On one end of the spectrum are materials with high core content, which display
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properties similar to crystalline solids, stiff waxes, and gels. At the opposite extreme are
systems that spontaneously form particle-based ionic fluids characterized by transport
properties remarkably similar to simple liquids comprised of molecular building-blocks,
but with negligible vapor pressures and high dielectric constants. These features are
advantageous for a broad range of applications, including zero-vapor pressure solvents,
heat-transfer liquids and lubricants, thin-film optoelectronic devices, high refractive
index liquids for immersion lithography, where colloidal suspensions either cannot be
used or require specialized design conditions to reduce solvent loss.
NANOFLUIDS FOR COATINS AND RESINS
Zhiming Qiu and John Texter, Coatings Research Institute, Eastern Michigan
University, Ypsilanti, MI 48197, USA; [email protected]
263
Recent research by Giannelis and co-workers has led to the invention of colloidal
particles surface functionalized with ionic liquid types of organic salts that form solventfree supramolecular liquids or nanofluids. Such surface functionalized nanoparticles can
be further functionalized to make them suitably reactive for formulating resins and
coatings. When such nanoparticles are functionalized with acrylate groups and mixed
with other difunctionalied cross-linking agents, zero VOC coating formulations are
obtained that can be used to make abrasion resistent clear coats curable by UV. When
isocyanate or isothiocyanate functionalized nanofluids are made and mixed with
diisocyanates, zero VOC coatings can be made that air cure into protective resins. Amine
surface functionalization produces nanofluids that can be used to produce UV-resistant
epoxy coatings when co-solubilized with aliphatic diglycidyl ethers. A roadmap for using
such nanofluids for diverse nanocomposite applications is outlined.
MOLECULAR ENGINEERING OF INORGANIC NANOPARTICLES
AND MESOSTRUCTURES
Michael Z. Hu, ,Oak Ridge National Laboratory, Oak Ridge, Tennessee
37831-6181, USA; Phone: 865-574-8782; Email: [email protected]
264
Molecular Engineering (ME) in combination with nanoscale process engineering, aiming
at molecular-level chemical engineering of surfaces/interfaces and porous nanostructures,
has emerged as one of the fastest-growing research areas at the frontier of science to
precisely create novel functional inorganic nanomaterial architectures and devices for
diverse applications. ME here refers to the processes of “engineered” self-assembly
which involve both chemical reactions and non-reactive physicochemical interactions.
This presentation will focus on our research efforts toward nanostructure tailoring/control
of functional nano-materials and their energy, medical, and biotechnology applications.
First, various nanoscale process engineering approaches will be discussed to enable the
control of nanoparticle size and morphology as well as ceramic membrane
nanostructures. Afterwards, the "engineered” assembly of molecular precursors into
inorganic and inorganic-organic hybrid superstructures will be dealt with. Particularly,
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our pioneering development of highly oriented meso-structures with porous channels of
ca. 7.5 nm in diameter arranged in an ordered array in a large area, together with
structured nanowires in ordered arrays will be highlighted. We have demonstrated the
high performance of these oriented and structured nanomaterials in diverse applications
such as bioseparations in DNA sequencing and fuel cell membranes with a significant
enhancement in ionic conductivity as high as three to four orders of magnitude.
Furthermore, our on-going efforts on constructing quantum dot superstructures will be
used as an example for ME of nanoparticle surfaces. Finally, my future research
perspective on molecular engineering and nano-materials will be briefly discussed.
BIOMIMETIC ASSEMBLY OF FUNCTIONAL NANOPARTICLES
Song Jin, Department of Chemistry, University of Wisconsin-Madison
1101 University Avenue, Madison, WI 53706, USA, [email protected]
265
Nature adopts a superior approach to nanomaterials assembly in biomineralization. We
apply the principles derived from biomineralization processes to the assembly of
nanoscale functional materials into nanoscale systems. By carefully controlling surface
organic molecules to promote heterogeneous nucleation at designated regions while
completely suppressing homogeneous nucleation elsewhere, we enable the controlled
bottom-up assembly of inorganic nanomaterials directly from solution. Following this
principle, surface carboxylic groups on selective regions were generated on commodity
engineering polymers such as polycarbonate (PC) and poly(ethylene teraphthalate) (PET)
by direct patterned UV irradiation through a photomask and then were successfully
employed to selectively nucleate nanoscale crystalline inorganic materials, such as
semiconductors ZnO and CdS, directly from aqueous solutions to form patterned arrays.
We have demonstrated the application of such arrays of functional materials for
macroelectronic applications. We have extended this biologically inspired approach to
truly bottom-up nanoscale assembly of nanoparticles using self-assembled nanostructured
block copolymers. We are exploring self-assembled synthetic collagen protein and β–
peptide fibrils with known molecularly controlled sequence to specifically nucleate and
assemble diverse family of inorganic nanocrystals.
SINTERING METAL NANOPARTICLES
Howard Wang, Department of Mechanical Engineering, Center for
Advanced Microelectronics Manufacturing, Binghamton University, SUNY,
Binghamton, NY 13902, USA; [email protected]
266
We have carried out several measurements in order to understand the process of metal
nanoparticle (MNP) film sintering. Small angle neutron scattering has been used to
reveal the average diameters of silver and gold nanoparticles (Ag-NPs and Au-NPs) used
in this study to be 4.6 and 3.8 nm, respectively, with a size distribution of ca. 20%. Spuncast Ag-NP and Au-NP films have been sintered at temperature ranges of 80 - 160 oC and
180 - 210 oC, respectively, for various times. The resulting film composition,
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morphology and electric resistance have been revealed. Upon sintering, the organic
content in MNP films reduces to less than 10% while the overall film thickness reduces
to about the half of the as-cast film thickness. The resistance of sintered Ag-NP films can
vary over more than 7 decades depending on the sintering temperature. The conductivity
of Ag-NP films sintered at 150°C is 2.4 × 10-8 Ωm. The transport properties are affected
by both the composition and morphology of sintered films.
MULTIFUNCTIONAL POLYELECTROLYTE/NANOPARTICLE
COATINGS
Anindarupa Chunder, Ghanashyam Londe, Kenneth Etcheverry, Hyoung J.
Cho and Lei Zhai, NanoScience Technology Center, Department of
Chemistry and Department of Mechanical, Materials and Aerospace
Engineering, University of Central Florida, Orlando, 32826, USA;
[email protected]
267
Multilayer coatings fabricated from polyelectrolytes such as poly(allylamine
hydrochloride) (PAH) and silica nanoparticles provide various surface structures for
superhydrophilic, superhydrophobic and hydrophilic/hydrophobic switchable coatings. A
superhydrophilic surface ultizes the nano-cappliary effect attributed to the nanoporous
silica nanoparticle network. A superhydrophobic surface was obtained by depositing
hydrophobic materials onto a mulitlayer films with dual micro- and nanoscale structures.
The thermal switchable surface is obtained by coated the multilayer film with the
thermosensitive polymer poly(N-isopropylacrylamide) (PNIPAAm). The water contact
angle on the surface changed from 122 degrees at 70 oC to 25 degrees at 25 oC. These
multifunctional coatings were conformally deposited onto microfluidic channels and two
fully integrated microfluidic valves, one with a superhydrophobic polymer surface and
the other with a switchable, thermosensitive polymer surface have been fabricated and
tested. The passive valve with the superhydrophobic polymer surface selectively inhibits
the flow of aqueous solutions without surfactants and passes aqueous solutions
containing surfactants. In case of the thermosensitive valve, the switchable polymer
surface becomes hydrophobic when heated to temperatures exceeding 65oC, thus
inhibiting the flow of water and becomes hydrophilic at room temperature, thus allowing
the flow of water.
PREPARATION AND PROPERTIES OF CLAY-BASED SELFSTANDING FILMS
Takeo Ebina, National Institute of Advanced Industrial Science and
Technology, Nigatake 4-2-1, Miyaginoku, Sendai, 983-8551, JAPAN; [email protected]
268
We succeeded in preparing flexible-thin films having gas barrier property, visible-lighttransparency, and heat durability by casting aqueous dispersions of synthetic hydrophilic
clay mixed with a little amount of water-soluble organic polymer. The film has a high gas
barrier property against inorganic gases such as hydrogen and oxygen up to 600°C. Its
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flexibility is similar to that of ordinary copying paper, and it can be cut, folded, and bent
as desired. The dimensions stability is smaller than 10 ppm in the wide range of
temperature. Transparent films were successfully prepared by using synthetic clays. The
total light transmission ratio of those films exceed 90%. X-ray diffraction patterns
suggest a unique close-packed lamination-structure of the films which may bring the
superior heat durability. The developed films will be promising for wide variety of
optoelectronic applications.
ENZYME QUANTUM DOT FACTORY
Roger M. Leblanc, Department of Chemistry, University of Miami, Coral
Gables, FL 33146, USA; [email protected]
325
The most common and classic procedure for the synthesis of semiconductor quantum
dots (QDs) involves high temperature inorganic methods that require the use of highly
toxic precursors. More recently, green and biologically relevant methods utilizing
bacteria have been proposed; however, these bacterial QD factories still do not overcome
the need for a second conjugation step necessary to make the QDs biologically active.
Recently this limitation has been overcome through the use of enzymes and proteins as
matrix. Bovine serum albumin (BSA), β-casein, and organophosphorus acid anhydrolase
(OPAA) have been used as ligands in the synthesis of protein stabilized CdS QDs in a
one pot synthesis via arrested precipitation; there is no need for a separate QD-protein
conjugation step. The proteins used vary in molecular weight, isoelectric point, and
biological function, however, all act as a suitable matrix for QD formation. OPAA
stabilized QDs retain their biological activity and may be used without further
modification for the detection of diisopropylfluorophosphate (DFP) at the nanomolar
level in addition to hydrolyzing DFP into a less toxic product.
ASSEMBLIES OF HYDROPHILIC BLOCK COPOLYMERS TEMPLATES FOR NANOPARTICLES AND NANOMATERIALS
SYNTHESIS
Corine Gerardin; Institut C. Gerhardt, ENSCM CNRS UM2 UM1
Montpellier, France, [email protected].
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Double hydrophilic block copolymers (DHBCs) have attracted much attention in the past ten
years with the development of many studies mainly in two fields : first, the polymer-controlled
mineralization, especially the growth of crystals and inorganic nanoparticles of tunable size and
shape, secondly the formation of polymeric micellar assemblies for their potential applications as
drug carriers. The increasing interest in DHBCs is due to the capacity of these polymers, which
are initially hydrosoluble, to acquire an amphiphilic character in water upon a change in a
physico-chemical parameter of the system or upon addition of a substrate, which can be an ion, a
molecule or a particle. The selective insolubilization of one of the polymer blocks leads to the
formation of nano-aggregates, whose size and stability are tunable, giving them promising
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applications in different fields. In the present paper, we focus on the case of micelles of DHBCs
induced by complexation of an oppositely charged entity and we describe the use of
complexation induced micelles for first, the preparation of hybrid organic-inorganic nanoparticles
and second, the synthesis of long-range ordered hybrid mesostructured materials. In the first case,
the induced DHBC assemblies result from the formation of a metal coordination complex and are
used as nanoareactors for the growth of nanoparticles by inorganic polycondensation in
suspension. In the second case, the induced DHBC assemblies are polyion complex (PIC)
micelles formed by electrostatic complexation between oppositely charged polyelectrolytes, and
are used as new templates for preparing mesostructured hybrid silica-based materials.
LIPASE CATALYZED POLYCONDENSATION REACTIONS IN
MINIEMULSION TO SYNTHESIZE POLYAMIDE NANOPARTICLES
Lakshminarayanan Ragupathy1, Ulrich Ziener1, Katharina Landfester1,
Harald Keller2, Motonori Yamamoto2 and Rainer Dyllick-Brenzinger2
1
Institute of Organic Chemistry III-Macromolecular Chemistry, University of
Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany; 2BASF
Aktiengesellschaft, 67056 Ludwigshafen, Germany;
[email protected]
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The process of miniemulsification allows one to generate small droplets (30 to 500 nm),
which could be efficiently used as nanoreactors to perform a number of different
polymerizations. Recently, lipase catalyzed polymerization in miniemulsion was found to
be highly attractive to produce polyester nanoparticles because of its several advantages
over enzyme catalyzed reactions in homogeneous phase such as (i) very low amount of
lipase (0.125%), (ii) high molecular weight polymeric nanoparticles, and (iii) lower
reaction time, i.e. < 24 h, for complete conversion. This is because of the interfacial
activation of lipases and the enzyme is operating in its natural environment from the
water phase attached to a hydrophobic surface. Here, we are presenting lipase catalyzed
polycondensation reactions in aqueous miniemulsion to synthesize nanoparticles
consisting of the polyamides such as nylon-8,10 and nylon-9,10. FT-IR and DSC were
used to analyze these products while 1H NMR was employed to calculate the chain length
of the formed oligomers and polymers. Kinetic studies on lipase catalyzed reactions
between diethyl sebacate (DES) and 1,8-diaminooctane (DAO) were carried out at
different reaction temperatures, i.e. 40, 50, 60, 70 and 80 °C. The required time for lipase
to produce a single amide bond between DES and DAO is observed to be 10 minutes
with a 90% conversion. The number of amide bonds is observed to increase with
increasing reaction time. Among the temperatures investigated, the lipase produces a
comparably high number of amide bonds, i.e. 24.9 in a single molecule at 70 °C after 48
hours. The reactions without lipase also make amide bonds between diester and diamine,
however the reaction rate is observed to be low, i.e. 1.5 in a single molecule at the same
reaction condition.
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IN SITU AND EX SITU TIME-EVOLUTION STUDY OF
PHOTOLUMINESCENCE FROM ZnO/MgO CORE/SHELL QUANTUM
DOTS
Debasis Bera, Lei Qian, Paul H. Holloway; Department of Materials Science
and Engineering, University of Florida, Gainesville, Florida 32611 USA;
[email protected]
328
In situ and ex situ time–evolution of photoluminescence data during growth of ZnO/MgO
core/shell quantum dots were used to study the stability of the green-white (CIE: 0.32,
0.41) luminescence. The ZnO/MgO core/shell quantum dots, synthesized by a sol-gel
process, exhibited a quantum yield 13 % compared to less than 5% for ZnO Qdots. The
growth of ZnO Qdots was arrested by growth of the MgO shell. UV-Vis absorption data
verified the quantum confinement of ZnO by a shell of MgO. Photoluminescence
emission from defects in the ZnO/MgO quantum dots was stable for more than 65 days at
room temperature. The integrated area of intensity for the greenishwhite luminescence
peak was ~ 100 times larger than that of the band-edge UV emission peak at ~350 nm.
A NOVEL ROUTE TO HIGHLY TUNABLE EMULSIONS INCLUDING
SINGLE STEP MULTIPLE EMULSION FORMATION
Bernard P. Binks, Paul D.I. Fletcher and Benjamin L. Holt, Surfactant and
Colloid Group, Department of Chemistry, University of Hull, Hull, HU6
7RX, UK; [email protected]; Kenneth Wong, Pascal Beaussoubre,
Firmenich SA, Geneva, P.O. Box 239, CH-1211, Switzerland;
[email protected], [email protected]
329
Solid-stabilised emulsions comprising water, limonene and dichlorodimethylsilane
(DCDMS)-modifed fumed silica nanoparticles, have been prepared without predispersion of the particles in either phase. The rheology, stability and continuous phase
type of the resulting emulsions are controlled by subtle adjustments in particle
concentration as well as extent of homogenisation, when using a single particle type in a
batch emulsification process. This novel protocol also allows control over drop size and
shape, as well as the production of multiple emulsions in a single emulsification process.
The highly tunable nature of these batch emulsions is attributed to particle surface
heterogeneity resulting in differences in wettability between dispersed and aggregated
particles.
MICRO-ALGAE AND NANOPARTICLES: TOWARDS “LIVING”
MATERIALS. BIO-CONTROLLED SYNTHESIS OF NANOPARTICLES
WITH OPTICAL AND MAGNETIC PROPERTIES
Roberta Braynera, Claude Yéprémianb, Chakib Djediatb, Thibaud Coradinc,
Jacques Livaged, Alain Coutéb, Fernand Fiéveta; aITODYS, Université ParisDiderot, Paris, France; bLaboratoire de Cryptogamie, Muséum National
330
170
d’Histoire Naturelle, Paris, France; cCMCP, Université Pierre et Marie Curie,
Paris, France; dCollège de France, Paris, France;
[email protected]
Natural strategies for the synthesis of nanomaterials are an important aspect of
nanotechnology today. Up to now, most of the synthetic preparation methods reported
rely heavily on organic solvents and the reducing agents used such as hydrazine and
sodium borohydride pose potential environmental and biological risks. At present, to
avoid environmental disasters, there is a growing need to develop nontoxic procedures
for synthesis and assembly of nanoparticles such as biomimetic approaches for the
growth of advanced materials. Biomineralization processes often imply the formation of
nanoparticles or nanocrystals, organized at larger scales via the self-assembly properties
of templating macromolecules. It should be also possible to use the synthetic capabilities
of living cells for the design of new nanomaterials. In this work, we show that the
common Anabaena, Calothrix and Leptolyngbya cyanobacteria and Euglena gracilis are
able to form Au, Ag, Pt and Pd metallic nanoparticles and also Fe based nanomaterials
such as Fe3O4 and FeOOH of well-controlled size and shape. The metallic nanoparticles
are synthesized intracellularly, and naturally released in the culture medium where they
are stabilized by the exo-polysaccharides, allowing their easy recovery. Euglena gracilis
can synthesize Fe3O4 and FeOOH. The magnetic behavior of these “living” materials
depends on the nanoparticle structure, size and shape. Moreover, the size of the recovered
particles as well as the synthesis yield is shown to depend on the micro-algae family and
genus, demonstrating the flexibility of this approach.
AMPHIPHILIC DIBLOCK AND TRIBLOCK STABILIZERS FOR
WATER-DISPERSABLE NANOPARTICLES
Fabienne Gauffre, Jean-Daniel Marty, Christophe Mingotaud, Kamil
Rahme, Javier Jubio Garcia and Stéphanie Sistach, IMRCP Laboratory,
University of Toulouse, France. [email protected]; Myrtil Kahn,
LCC-CNRS, France
331
Since it was discovered that metallic and semi-conducting nanoparticles have unique
optical properties, many biomedical applications have been proposed for these
nanomaterials, in the fields of imaging, sensing, and therapy. However, all biomedical
applications require water dispersability and long term stability of the nanoparticles at
high ionic strength. The synthesis of well-defined metallic and semi-conducting
nanoparticles are usually achieved in organic solvent, producing particles with a
hydrophobic surface. Hence, the obtention of water-dispersible nanoparticles by direct
synthesis or transfert is still a challenging task. Our group develops new strategies to
produce various water dispersible nanoparticles, using designed amphiphilic stabilizers.
Indeed, the self-assembling properties of amphiphilic compounds provide (i) enhanced
adsorption at the surface of the particles; (ii) stabilization through non-covalent
interactions with the surface, that avoids modification of the nanoparticles properties and
direct generalization to particles made of various materials. We have investigated the
stabilizing efficiency of various amphiphilic compounds with a diblock A-B structure
171
(A= hydrophilic, B= hydrophobic), such as surfactants and diblock copolymers, or with a
triblock A-B-A structure: bola-amphiphile surfactants, triblock copolymers, coremultishell hyperbranched polymers. One of the main results is that triblock amphiphilic
structures act as efficient stabilizers even in conditions where the formation of selfassembled objects (micelles, vesicles...) does not occur in solution (for instance at
concentrations lower than the critical agregation concentration). The predominent role of
the length of the hydrophobic B segment, for the colloidal stability is clearly evidenced.
In addition, the use of bolaamphiphile surfactants with charged polar head and long alkyl
chains (n>12) allows one to precipitate and redisperse the nanoparticles at will. Long
term stability in condition of high ionic strength can be achieved by an appropriate choice
of non ionic A-B or A-B-A copolymers, for instance made of hydrophilic oxyethylene
and hydrophobic oxypropylene segments. Finally, core-multishell polymeric structures
designed with a careful choice of their external groups exhibited a remarkable behviour,
combining extremely long term stability with dispersabitlity of hydrophobic and
hydrophilic nanoparticles in a wide range of solvents (from water to chloroform).
DEVELOPMENT AND EXPLORATION OF CARBON NANOTUBES
TOWARDS USE AS PROBES AND AGENTS IN PHYSICAL AND LIFESCIENCES
Tobias Hertel, Vanderbilt University, Physics and Astronomy, 6301
Stevenson Center Lane, Nashville, TN 37235, USA,
[email protected]
332
NANOSENSOR-BASED DETECTION OF OXYGEN IN BIOSAMPLES
Piotr J. Cywinski, and Gerhard J. Mohr, Institute of Physical Chemistry,
Friedrich-Schiller University Jena, 07743 Jena, Germany;
[email protected]
333
The balance between oxygen supply and oxygen consumption is of paramount
importance for tissues as well as microorganisms. In many diseases regional hypoxia is
either a primary causative or an early contributing factor. The interest in determining the
content of oxygen has spurred the development of oxygen sensing techniques starting
from the first amperometric sensors through fiber optic based devices into the field of
fluorescent polymer nanosensors. Oxygen electrodes or fiber optic based devices are
useful to measure global oxygen content, but they are invasive and can only measure
oxygen at the tip of the electrode at one point at a time. This makes it difficult to measure
the oxygen distribution and to evaluate oxygen heterogeneities in ischemic tissues or
microorganisms. Luminescent ratiometric nanosensors made of polystyrene have been
developed for monitoring molecular oxygen in biosamples. The oxygen-sensitive dye
platinum meso-tetra(pentafluorophenyl)porphyrine (PtTPFP), and the oxygen-insensitive
172
reference fluorophore N,N’-bis(1-hexylheptyl)perylene-3,4:9,10-bis-(dicarboximide)
were incorporated into the particles to make them ratiometric. Additionally, the surfaces
of nanosensors were functionalised for better biocompatibility and solubility in aqueous
media. The size of the nanoparticles was determined by dynamic light scattering
technique to be 120±10 nm. In order to asses the response of sensors to oxygen, a set of
measurements in aqueous suspension, yeasts culture as well as in living cells has been
carried out. In all cases the quenching of PtTPFP phosphorescence with increasing
oxygen content was observed. At the same time fluorescence emission of the reference
remained unaffected. The relationship between the sensor fluorescence and the oxygen
content has been evaluated using the Stern-Volmer equation yielding a Stern-Volmer
constant of 26±1 M-1.
SYNTHESIS AND CHARACTERIZATION OF PHOTOLUMINESCENT
COLLOIAL QUANTUM DOTS FOR CANCER CELL IMAGING
Kui Yu, Steacie Institute for Molecular Sciences (SIMS), ational Research
Council Canada (NRC), 100 Sussex Drive, Ottawa, Ontario Canada K1A
0R6; [email protected]
334
Photoluminescent (PL) semiconductor nanocrystals, when spherical in shape also termed
as quantum dots (QDs), have attacted significant attention as optical imaging agents for
nanomedicine studies. Usually, such bio-oriented applications require targeting to the
site of interest, and the use of antibodies is acknowledged as one common strategy for
specific and compelling targeting. In this presentation, we will address our efforts on the
development of various nanocrystals exhibiting high-quality PL as well as on the bioconjugation for cancer cell targeting and imaging. The development of PL high-quality
colloidal nanocrystals foucses on the synthesis-structure-property relationshp, and will be
demonstrated by PL ZnCdS QDs with gradient distribution of components, Cd-rich inner
cores and Zn-rich outer shells, synthesized via a non-injection one-pot approach. For the
cancer cell targeting and imaging, a single domain antibody (sdAb) named EG2 is
chosen, which binds strongly to epidermal growth factor receptor (EGFR), a protein of
which is widely known as a tumor marker. The entity of our sdAb-conjugated QDs is
robust in bio-labeling.
COOPERATIVE PLASMON-MEDIATED MOLECULE FLUORESCENCE
NEAR METAL NANOPARTICLES
V. N. Pustovit and T. V. Shahbazyan, Department of Physics, Jackson State
University, Jackson, MS 39217, USA; [email protected]
335
We study theoretically radiative and nonradiative decays of an ensemble of molecules
attached to a metal nanoparticle. We show that when the system size is smaller than the
radiation wavelength, the excited molecular dipoles are hybridized with each other via
the nanoparticle surface plasmon, leading to cooperative plasmon-mediated emission
similar to Dicke superradiance. In particular, an ensemble of N fluorescenting molecules
173
adsorbed at random positions on nanoparticle surface has only 3 bright (superradiant)
eigenstates each characterized by the single-molecule plasmon-enhanced radiative decay
rate multiplied by approximately N/3, while the remaining N-3 states are optically dark
(subradiant). The fluorescence quenching by the nanoparticle exhibits a similar behavior,
with bright states having single-molecule nonradiative decay rate multiplied by the same
factor and dark states having much longer but still finite non-radiative lifetime due to
contribution of higher angular momenta. As a result, the radiation power of an ensemble
is only thrice that of a single molecule near a nanoparticle irrespective to total number of
molecules.
TITANIUM OXIDE NANOTUBE SYNTHESIS AND SURFACE
MODIFICATION FOR DNA TRANSFECTION
Anne-Laure Papa1, Nadine Millot1 and David Vandroux2; 1 Institut Carnot
de Bourgogne, UMR 5209 CNRS - Université de Bourgogne, BP 47870,
21078 Dijon cedex, France ; 2 Institut de Recherche Cardiovasculaire, Centre
Hospitalier Universitaire, 21034 Dijon, France; [email protected];
[email protected]
336
The cultures of neonatal rat cardiomyocytes (CM) represent a very useful tool for the
observation and the understanding of the cellular aspects of cardiac diseases. However,
their uses were limited by low transfection efficiency with conventional techniques
unless viral vectors which provide stable, long-term transgene expression.
The present study presented the development of a highly efficient novel non-viral vector
for cardiac myocytes based on the use of functionalized titanium oxides nanotubes
(TiON). TiON are synthesized by a hydrothermal treatment (150°C, 4 bar) in a strongly
basic conditions (NaOH, 10 mol/L). They have a tubular morphology being rolled up in
spiral with an inner cavity and they are charged in surface with hydroxide groups.
Moreover, these nanomaterials develop large specific surfaces. Transmission Electron
Microscopy data shown that up to 80% of TiON were internalized in CM without sign of
toxicity, suggested that this type of nanotubes would be a useful nanovectors for
transfection of this well-known difficult cells. Our results show that functionalized these
TiON with PEI allow the binding of DNA and its transfection in CM. Our results suggest
that further development of these TiON may provide a new useful tool for research and
clinical gene therapy in the field of cardiovascular disease.
BIOFUNCTIONAL CORE-SHELL NANOPARTICLES FOR BIOCHIP
MANUFACTURING BY PRINT PROCESSES
Achim Weber, Kirsten Borchers, Sandra Genov, Thomas Hirth, Guenter
Tovar, Fraunhofer-Institute for Interfacial Engineering and Biotechnology,
Nobelstr. 12, 70569 Stuttgart, Germany, [email protected]
337
174
Nanoparticles display a very large surface-area. Therefore, coatings of functional
nanoparticles adsorbed to a solid substrate yield an enlarged interface per footprint-area
which is highly appreciated for probe-immobilization in bio-chip technology. Silica
nanospheres, equipped with an organic shell, can be used to couple specific captureproteins or DNA-probes. Further to spotting of biofunctional nanoparticles in a micro
arrayed format, the generation of a covering nanoparticle-coat in a user-defined shape
allows for flexible assay-design and for fabrication of large bioconjugative interfaces on
both, glass and polymer substrates. In view of the advantages that have been experienced
in the past decade using biochip- based screening-approaches, biochip-production should
be made a cheap, flexible and reproducible process. In order to set up an automated
production-line for nanoparticle-based bio-chips we are developing an ink-jet printing
process that is compatible with the treatment of biomolecules and that allows for high
flexibility as well as accuracy in nanoparticle deposition. We will present results
concerning substrate-activation, ink-preparation, the print-performance treating inkformulations containing (bio)functional nanoparticles and the maintenance of biological
functions during the ink-jet process.
MULTIMODAL/MULTIFUNCTIONAL NANOPARTICLES FOR
Swadeshmukul Santra, NanoScience Technology Center, Department of
Chemistry and Biomolecular Science Center, University of Central Florida,
12424 Research Parkway, Suite 400, Orlando, FL 32826, USA;
[email protected]
338
In recent years, multimodal/multifunctional nanoparticles have attracted tremendous
attention in biomedical research such as cancer imaging, stem cell tracking, drug delivery
etc. In this direction, we have developed various types of biocompatible core-shell
fluorescent, radio-opaque and paramagnetic multimodal/multifunctional nanoparticles
using water-in-oil microemulsion method. In this presentation, I will talk about
development of silica and chitosan based multimodal/multifunctional nanoparticles as
sensitive contrast agents for bioimaging and biosensing applications. The design and
synthesis strategy of controlling particles size, aqueous dispersibility, biocompatibility
and targetebility of nanoparticles will be discussed in details. Research data
demonstrating both in vitro and in vivo applications of these nanoparticles will be
presented.
APPLICATION OF NANOGOLD TO BIOMOLECULAR RECOGNITION
Long Jiang, Beijing National Laboratory for Molecular Sciences (BNLMS),
Key Laboratory of Colloid and Interface Science, Institute of Chemistry,
Chinese Academy of Sciences, Beijing 100080, P. R. China.
[email protected]
339
175
QCM surface modified with nanogold resulted in a great enhancement of fixation amount
of single strain SH-DNA, which in turn increased the hybridization of target DNA. When
nanogold attached to the end of target DNA the recognition sensitivity will increase to an
extent of several orders. With a sandwich mode of DNA hybridization the detection
ability to a target DNA consisted of 17 bases could improved from 10-12 mol/L to 10-16
mol/L. The effect of nanogold have been studied with electrochemical and mechanical
property, which showed the high curvature of nanoparticles could provided more room
for hybridization, and fixation strength of single strain DNA on the substrate could be
improved by the dense packing of nanoparticles on the surface. Our experimental results
showed that small nanogold on the larger gold ball surface can be a better collector of
DNA in gene gun and microfluidic system application.
SPIDER SILK PROTEINS - BIOPOLYMERS FOR ENCAPSULATION,
COATINGS AND MORE
Thomas Scheibel, Dept. of Biomaterials, University of Bayreuth,
Universitätsstr. 30, 95440 Bayreuth, Germany;
[email protected]
340
Biological materials often exceed the characteristics and properties of man-made ones.
One well-known example is spider silk with superior mechanical properties such as
strength and toughness. Most spider silks are used for building the web, which reflects an
optimized trap for flying prey. Already thousands of years ago the excellent mechanical
properties and low immunogenicity of spider webs have been acknowledged by men,
employing them as fishing nets or as wound closure devices. However, large-scale
farming of spiders has been quickly abandoned due to the territorial and cannibalistic
behavior of most spiders. In order to avoid such complication, we developed a bioinspired system using bacteria as production hosts which produce silk proteins mimicking
the natural spider silks. Besides the protein fabrication, we have developed a spinning
technique to produce spider silk threads closely resembling natural silk fibers.
Importantly, we can employ the bio-inspired silk proteins also in other application forms
such as microcapsules or films useful for encapsulation or surface coatings. Our bioinspired approach serves as a basis for new materials in a variety of medical, biological,
or chemical applications.
OLIGONUCLEOTIDE-COATED METALLIC NANOPARTICLES AS A
FLEXIBLE PLATFORM FOR MOLECULAR IMAGING AGENTS
G. Rossini, S. Crumlett, N.Nitin, J. Trevino, B. Goins1, N. K. Vail2,
Southwest Research Institute, San Antonio, TX, USA; 1UTHSCSA San
Antonio TX, 2Kinetic Concepts, Inc., San Antonio, TX, USA;
[email protected]
341
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We have developed and characterized PLGA/PLGA-PEG nanoparticles for the purposes
of providing targeted delivery of therapeutic agents to bone. We further demonstrate the
encapsulation of a gamma-emitting radionuclide in these nanoparticles to study their in
vivo biodistribution. Previous research has used surface modification to attach
radioactive ligands to study nanoparticle biodistribution, however this approach can
change the nanoparticle biodistribution properties. In this study, Tc99m (t1/2 ~6 hours)
was conjugated to a model protein and encapsulated within nanoparticles using a custom
w/o/w encapsulation protocol, which was optimized to produce labeled nanoparticles
within 4 hours. This protocol can be used to prepare nanoparticles with narrow size
distribution in the range of 100 to 200nm by controlling the process conditions. The
encapsulation efficiency of Tc99m was approximately 5%. Nanoparticles were
formulated from an 80/20 (w/w) mixture of PLGA (75/25 Lactide/Glycolide, 50-70 kDa)
and either a custom synthesized PLGA-PEG (PLGA 50 kDa ave Mw, PEG 2 kDa) or
custom synthesized PLA-PEG-Asp4 (PLA 48 kDa Mw, PEG 2 kDa), where Asp4 is an
aspartic acid oligopeptide to target bone. The biodistribution of two nanoparticle
formulations, 120±30nm and 200±30nm, was determined in C57BL/KaLwRij mice,
which develop myeloma disease when inoculated with murine 5TGM1 myeloma cells.
Nanoparticles (200 μL, ~0.5mCi) were administered via tail vain injection.
Biodistribution was followed by Micro-CT scan and blood samples collected at 1, 2, 4,
20 and 40 hours. Micro-SPECT was performed on selected animals. Nanoparticle
clearance from the blood was determined by counting blood samples collected from
retro-orbital sinus at various times post-injection. Tissues were harvested post mortem at
44 hours post injection. Samples were weighed and counted, and organ distributions
calculated as a % of dose/gram of tissue. We found that smaller particles remained in the
circulation longer during the first four hours post-injection (27.18±4.01%) compared to
larger particles (1.54±0.29%). After 44 hours a small amount radioactivity (1.38%±0.13)
was found in the kidney confirming that the label was stable in vivo. The main difference
between 200nm and 120nm particles was that bigger particles end up mostly in the liver
(36.513±1.359) and smaller particles distribute mostly in the spleen 56.756±13.401 and
liver 31.073±1.589. The above results were confirmed by Micro-SPECT performed at 2
hours. Total bone distribution was 5.586±0.654 for 200nm particles and 9.739±1.123 for
120nm particles. Future work will determine the bone targeting capability of long
circulation nanoparticles by functionally modifying the surface with Asp4 a bone
targeting agent.
BIOMIMETIC PROCESSING OF SOFT-HARD CORE-SHELL
MICROCAPSULES
Mark A. Bewernitz, Palanikumaran Muthias, Adria Suarez, Laurie B.
Gower; Department of Materials Science & Engineering, University of
Florida, Gainesville, FL 32611-6400, USA; [email protected]
342
Core-shell microcapsules are being prepared which contain a fluidic core, such as an oil
droplet, surrounded by a mineral shell of calcium carbonate. These “hard-“soft” particles
are synthesized by coating surfactant-stabilized emulsion colloids with a mineral shell,
177
using a polymer-induced liquid-precursor (PILP) mineralization process developed in the
Gower lab. In this process, a highly hydrated amorphous precursor to the mineral is
generated using a polymeric process-directing agent, such as polyaspartate, to generate
liquid-liquid phase separation in the reaction medium. Droplets of the mineral precursor
adsorb to and coat the emulsion colloids, and because of their fluidic character, they
coalesce to form a smooth and continuous mineral coating that encapsulates the oil
droplet, along with any active ingredients contained within the emulsion oil. Using
confocal microscopy, it has been demonstrated that the microcapsules can entrap an oilsoluble dye, and preliminary studies demonstrate that the calcite shell is readily
biodegradable. Morphological characterization of the particles by optical and scanning
electron microscopy shows that they are around 2 to 5 microns in diameter, with a
mineral shell thickness of several hundred nanometers. We are currently determining the
ability to tailor these parameters, as well as degradation rate of the shell. A variety of
commercial applications are envisaged for these biodegradable capsules, ranging from
pharmaceutical microcapsules for drug delivery, agriculture (release of catalyst, pesticide,
fertilizer), consumer products (cosmetics, skin and hair care), and self-healing
composites.
INNOVATIVE ENCAPSULATION FOR DIAMOND COMPOSITE
COMPACTION
Miriam Gathen, Evelina Vogli, Wolfgang Tillmann, Institute of Materials
Engineering, Technical University of Dortmund, Germany;
[email protected]
343
Diamond impregnated composites are frequently hot pressed. Further process routes are
pressureless sintering of green compacts partly combined with hot isostatic pressing and
hot isostatic pressing of encapsulated powder mixtures. In order to obtain a high
compaction sintered components with low porosity or impermeable capsules are
necessary for the hot isostatic pressing process. For that reason ultra-fine powder or
capsules made of metal or glass are employed. The Institute of Materials Engineering
pursues an innovative encapsulation process route: cold compaction of powder mixtures,
pressureless sintering in a vacuum furnace, physical vapor deposition (PVD) of a coating,
hot isostatic pressing. The thin PVD-coating acts similarly as a capsule and transfers the
pressure in the subsequent hot isostatic pressing process. For the implementation of this
process route two different bronze powders CuSn 85/15 (45-90µm, <40µm) and
diamonds (40/50 US-mesh, 300-450µm) were used and six different mixtures produced:
two pure bronze powder mixtures and a mixture of them (70% 45-90µm, 30% <40µm) as
well as the three bronze mixtures with diamond addition (10Vol.-%). The mixtures were
compacted at 550 MPa and pressureless sintered in a vacuum furnace at 993 K for 4
hours. In a PVD-process pure copper were deposited on the presintered composites. The
thickness of the coating ranged from 12µm to 16µm. Subsequently, the coated
composites were hot isostatic pressed at 993 K, 100 MPa for 4 hours. After the
pressureless sintering composites based on bronze particles 45-90µm showed a beginning
of neck formation, but also original grain boundaries (porosity ~18%). In composites
with mixed particle sizes (70% 45-90µm, 30% <40µm) the fine bronze particles filled the
pores between the coarse bronze particles and a slightly progressed sintering was
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observed (porosity ~13%). Composites based on bronze particles <40µm showed a
further development of neck formation (porosity ~11%). The diamonds were good
embedded in the bronze matrix with microstructures mentioned previously. After the hot
isostatic pressing of copper coated composites the microstructure of all composites were
clearly more compacted and a porosity reduction of approximately 10% were measured.
Consequently, the composites based on mixed and fine bronze particle sizes were in the
final stage of sintering with significant neck growth and elimination of grain boundaries.
Investigations of the copper coating on presintered composites showed that the coating
thickness should be more than 12µm to close the open pores of the composite surface.
Because the PVD-coating-process was performed under vacuum the pores were sealed
without enclosing gas that hinder the subsequent sintering. Diamonds on the surface of
the presintered composites were coated in the same way as the bronze matrix. While
conventional metal or glass capsules are of restricted geometry the innovative
encapsulation process route by means of PVD-coating offer a high geometric flexibility
and consequently, the realization of complex shaped diamond impregnated composites.
This novel encapsulation technique is suitable not only for diamond composites but also
for powder of difficult compactibility.
FABRICATION OF FUNCTIONALISED POLYURETHANE
NANOCAPSULES VIA INVERSE MINIEMULSION FOR EXPLOITING
AS CELL MARKERS
Umaporn Paiphansiri1, Sonu Sharma2, Julia Schmitz-Wienke3, Volker
Mailänder3, Anna Musyanovych1, Volker Rasche2, and Katharina
Landfester1; 1Institute of Organic Chemistry III - Macromolecular Chemistry
and Organic Materials, University of Ulm, Albert-Einstein-Allee 11, 89081
Ulm, Germany; 2Internal Medicine, University of Ulm, Robert-Koch-Str. 8,
89081 Ulm, Germany; 3Institute of Clinical Transfusion Medicine/Institute of
Transfusion Medicine, University of Ulm, Helmholtzstr. 11, 89081 Ulm,
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The concept of ‘nanoreactor’ prepared by the inverse (water-in-oil) miniemulsion process
was applied to encapsulate magnetic resonance imaging (MRI) marker, i.e. Magnevist®,
into the aqueous core of well-defined polyurethane (PU) nanocapsules. The inverse
miniemulsion was prepared by ultrasonication. The monodisperse aqueous nanodroplets
comprising the MRI solution, sodium chloride, and 1,6-hexanediol or dextrane were
dispersed in cyclohexane containing non-ionic surfactant, i.e. poly((butylene-coethylene)-block-(ethylene oxide)). The interfacial polycondensation takes place after
addition of 2,4-tolylene diisocyanate to the obtained inverse miniemulsion at 60 °C,
resulting in polyurethane nanocapsules. The nanocapsules obtained from the cyclohexane
phase were then redispersed into an aqueous solution of sodium dodecylsulphate. The
effect of molar ratio of diisocyanate to diol on nanocapsules characteristics, e.g.
nanocapsule size, shell thickness, encapsulation efficiency and T1 relaxivity of the MRI
marker was evaluated. In addition, the distribution of the marker in the nanocapsules was
elucidated by scanning transmission electron microscopy (STEM). Prior to further study
on the T1 relaxivity of nanocapsules, which contain the MRI marker in vivo, surface
modification of those nanocapsules is required to improve the ability of targeted cellular
uptake. Instead of incorporating the MRI marker into the core, pH independent
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fluorescence dye was, thus, utilised for in vitro imaging under the confocal laser scanning
microscopy (CLSM). The carboxymethylation reaction or adsorption of cationic
polyelectrolyte, e.g. polyethylenimine (PEI) or poly(aminoethyl methacrylate) (PAEMA),
on the nanocapsule surface was performed in order to introduce carboxylic or amino
groups, respectively. Comparing to the unfunctionalised fluorescent nanocapsules
(having zeta potential of -47 mV), the increase in number of the amino functionalised
nanocapsules (having zeta potential of +60 mV) leads to the enhanced incorporation into
HeLa cells after 24 h incubation time as demonstrated by CLSM measurements.
THE BEHAVIOR OF INDIVIDUAL MICRO/NANO CAPSULES
IMMERSED IN LIQUIDS
Michael Lefenfeld* and Curt Thies‡; *Columbia University, New York, NY
10027, USA; ‡Thies Technology, Henderson, NV 89014, USA;
[email protected]
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This presentation will focus on microscopic and spectroscopic experimental techniques
that can be used to characterize the behavior of individual microcapsules immersed in
liquids. Data discussed were obtained by observing the behavior of a number of
individual microcapsules drawn from several different types of capsules. Some capsules
were initially loaded with a highly water-soluble solid; others were loaded with a waterimmiscible solvent. The former were immersed in water and the latter in a variety of
organic solvents. Significantly, the behavior in liquids of individual capsules drawn from
a specific capsule sample varies greatly. Whereas some release their contents rapidly,
others release their contents extremely slowly. This observation is consistent with the
concept that microcapsules exhibit population or ensemble release behavior which can be
characterized by statistical methods. Although examining the behavior of individual
capsule in various solvents may be viewed as a time consuming process, such
measurements can make a significant contribution to encapsulation process development
and improvement studies and this will be noted.
CASEIN PROTEIN NANO GELS FOR ENCAPSULATION OF
MINERALS
Cornelis G. de Kruif1,2 and Thom Huppertz1; 1NIZO food research,
Kernhemseweg 2, 6718ZB, Ede, The Netherlands; 2Van ´t Hoff laboratory for
Physical and Colloid Chemistry, Debye Institute, Utrecht University,
Padualaan 8, 3584 CH, Utrecht, The Netherlands; [email protected]
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Caseins, the main proteins from milk, self-associate to form nanometer-sized micellar
structures. These micellar structures are capable of encapsulating and protecting small
mineral and other particles. Actually the biological function of the casein micelles in milk
is to transport 5 nm sized calcium phosphate clusters. The calcium phosphate is required
for the bone formation of the neonate. As an illustrative and technological interesting
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example, we used the casein protein for the encapsulation of magnetite particles. Since
magnetite is super paramagnetic, the so obtained particles can be manipulated and
collected by a (weak) magnetic field. The protein matrix of the gel particles was
stabilized by enzymatic cross linking. Such particles can also be functionalized so as to
separate proteins. The particles and the technology used is food grade.
Session M1 – Invited Paper
STRUCTURAL AND MAGNETIC PROPERTIES OF
MAGNETOPLUMBITE-TYPE CATIONS-SUBSTITUTED BARIUM
FERRITE NANOPARTICLES
G. B. Teh, Department of Bioscience and Chemistry, Universiti Tunku Abdul
Rahman, Kuala Lumpur, Malaysia; [email protected]
347
The magnetoplumbite-type (M-type) hexagonal ferrites of BaFe12O19 have been
investigated with the substitution of oxides of cobalt(II), cobalt(III) and titanium (IV), in
order to produce a quaternary system of the type BaO-Fe2O3-XO where X represents the
dopant cation. Ethylene glycol was employed as the precursor and this technique had
produced nanocrystallites of cation-substituted barium ferrites with particle sizes from
200-1000 Å. Co(II) substitution reduced the coercivity from 1082.39 G/mg in unsubstituted BaFe12O19 (363 Å) to 275.77 G/mg in BaCo(II)Fe11O19 (261 Å). Oxygen
vacancies of 2.4 % were detected in the Co(II)-substituted barium ferrite by the means of
thermogravimetry analysis. Co(II)-Ti(IV) substitution in BaCoXTiXFe12-2XO19 with X =
0.2 had exhibited an increase in both its remnant and saturation magnetization compared
to its un-substituted barium ferrite. Significant increase in line broadening of the XRD
patterns were observed indicating the decrease of particle sizes due to the Co(II)–Ti(IV)
substitution. BaCo3Ti3Fe6O19 showed the highest coercivity but moderate saturation and
remnant magnetizations. HRTEM imaging showed that Co(II)–Ti(IV) substitution in the
system of BaCoxTixFe12−2xO19 (x = 1–6) produced no drastic change in the structure of
the M-type ferrites. The HRTEM micrographs showed that BaFe12O19 is a well-ordered
compound with a lattice fringe spacing of 11.6 Å of the {002} planes. The barium ferrite
phase is found to be crystallized on the {111} plane of spinel iron oxide. The fine
structure of M-type barium ferrites was not changed by the Co(II)-Ti(IV) substitution
with majority of the crystals displayed a long axis perpendicular to the c-axis of the Mtype structure. Disordered crystals showing the intergrowth between Co–Ti-substituted
barium ferrite and the spinel-structured iron oxide were detected.
PREPARATION, CHARACTERIZATION, AND APPLICATIONS OF
(SUPER-)PARAMAGNETIC NANOPARTICLES
Aiguo Wu1, Tatjana Paunesku 1,2, Nicole Macheri2, Kenneth T. Thurn1,
Eric, M. Brown1, Debiao Li2, and Gayle E. Woloschak 1,2,3*
1
Department of Radiation Oncology, 2Department of Radiology, 3Department
of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern
University, Chicago, IL 60611, USA; [email protected]
* Corresponding Author
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There are many interests in (super-)paramagnetic nanoparticles such as magnetic storage
in informatics, magnetic separation of waste water treatment in environment science, as
well as contrast media in biomedical imaging. We prepared (super-)paramagnetic
nanoparticles in aqueous solution around room temperature in air no inert gas protection
during the whole preparation process. We will show some results from our group on
preparation methodology, properties, characterization, and applications of (super-)
paramagnetic nanoparticles particularly in bio/medical applications. We hope our results
can benefit for the research fields in the preparation of (super-)paramagnetic
nanoparticles via a simple and low-cost way as well as biomedical imaging based on
these water-soluble nanoparticles.
DESIGN AND PROPERTIES OF HYBRID MAGNETIC
NANOCARRIERS (HYMAC)
Yun Yang,a Michel Boissière,a Joachim Allouche,a Corinne Chanéac,a
Roberta Brayner,b Jacques Livagea and Thibaud Coradina. a CMCP,
Université P. et M. Curie-CNRS, 75252 Paris cedex 05, France. bITODYS,
Université Denis Diderot-CNRS,75251 Paris cedex 05, France;
[email protected]
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Hybrid nanoparticles associating alginate and silica were elaborated by spray-drying
technique. This procedure is compatible with the encapsulation of iron oxide colloids and
antibiotics. These nanoparticles could be up-taken by living cells and intra-cellularly
degraded while demonstrating limited cytoxicity. They could be surface-functionalized
with PEG chains and coated with gold colloids., with a significant impact on their cellular
incoporation Their drug release properties were investigated, indicating a two-step
degradation process that may arise from the difference in stability of the bio-organic and
inorganic components. By varying the silica/biopolymer content, it was observed that the
structure of these nanoparticles could evolve upon ageing from interpenetrating networks
to core-shell and hollow sphere morphologies. Surfactants were also introduced in order
to control the porosity of the silica network in the mesoporous range. Overall, these
hybrid magnetic nanocarriers (HYMAC) appear as promising platforms for the
development of multi-functional pharmaceutical materials.
SYNTHESIS AND CHARACTERIZATION OF MAGNETIC NANOPARTICLES FUNCTIONALIZED WITH β-CYCLODEXTRIN FOR BIOSEPARATION.
M S Uddin*, A Z M Badruddoza, K Hidajat, L Hong; Department of
Chemical & Biomolecular Engineering, National University of Singapore, 10
Kent Ridge Crescent, Singapore 117576; [email protected]
350
In recent years, the unique and physicochemical features of surface functionalized
magnetic nano-sized particles which are attributed to affinity of pendant functional
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groups and magnetic properties are gaining significant interest in the field of bioseparation and purification. In this study, the surfaces of magnetic nano-particles were
functionalized by grafting 6-ehtylenediamine-substituted β-cyclodextrin [β-CDX,
X=NH(CH2)2NH2]. The magnetic nano-particles (Fe3O4) were synthesized by chemical
precipitation method using Fe2+ and Fe3+ salt (1:2) with ammonium hydroxide under a
nitrogen atmosphere and vigorous stirring at 80°C followed by resuspension of the nanoparticles in water using thiodiglycolic acid (TDGA). As thiol (–SH) group in
thiodiglycolic acid has greater affinity for iron sites on surface, it is easily attached to the
iron particles through coordination bonding. This procedure produced Fe3O4 nanoparticles stabilized against agglomeration. Finally, β-CDX bonded nano-sized magnetic
particles were prepared through reaction between β-CDX and thiodiglycolic acid coated
magnetic particles. β-CDX was synthesized in two step procedures from β-CD via
preparation of 6-monotosyl β-CD (β-CDtosyl) which were also reported. The
characterization of the resulting nano-particles were carried out by transmission electron
microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron
spectroscopy (XPS), thermogravimetric analysis (TGA) and elemental analysis. TEM
results reveal the formation of single domain monodispersed nano-particles of mean
diameter of ca. 10.5 nm. The successful attachment of β-cyclodextrin on the surface of
magnetic nano-particles was ascertained from the results of FTIR, TGA, XPS and
elemental analyses.
FERROMAGNETIC CORE-SHELL NANOPARTICLES: GROWTH
CONTROL AND SURFACE CHEMISTRY
Tong Leung, WATLab and Department of Chemistry, University of
Waterloo; 200 University Avenue West, Waterloo, Ontario, N2L 3G1,
Canada; [email protected]
351
Our recent work on metal nanoparticles (Cu, Ni, Co, Mn, Cr, Au) electrochemically
deposited on a H-terminated Si substrate or on an ultrathin polypyrrole film grown on a
gold-coated Si substrate shows that the morphology (size, shape, density, and
distribution), and structural and chemical compositions of these nanostructured materials
can be easily controlled by varying the deposition conditions (pH, electrolyte
concentration, deposition potential, charge, and current density). Using similar
electrochemical techniques, we have recently obtained mono-sized, uniformly distributed
Fe core-shell nanoparticles with three different morphologies: nanospheres of 6-10 nm in
diameter, 25×130 nm oval-shaped nanorods (or “nanorice”), and nanocubes of 30-80 nm
side length. These nanoparticles are found to primarily consist of a Fe metallic core and
a mixed Fe oxides shell. In the present work, we report the first evidence of
morphological changes induced by an external magnetic field during growth. The
potential of using this magnetic-field-guided electrodeposition technique for constructing
“patterned” nanostructured materials and for other applications will be discussed. Our
recent results on the organic functionalization of these Fe core-shell nanoparticles (with
and without the presence of an external magnetic field) will also be presented.
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SYNTHESIS OF MAGNETIC NANOPARTICLES FOR BIOMEDICAL
APPLICATIONS
Everett Carpenter, Virginia Commonwealth University, Chemistry
Department, 1001 West Main Street, PO Box 842006, Richmond, VA 23284,
USA, [email protected]
352
Session M1 – Contributed Paper
NON-AQUEOUS SOL-GEL ROUTES TO DILUTED MAGNETIC
OXIDES
Guylhaine Clavel, Andrea Pucci, Marc-Georg Willinger, David Zitoun
Nicola Pinna, University of Aveiro, Department of chemistry and CICECO,
3810-193 Aveiro, Portugal and Institut Charles Gerhardt, CC15, Place
Eugène Bataillon, 34095 Montpellier, France; [email protected]
353
Nanostructured oxides play a major role in the development of functional nanoscale
materials and devices. Among them, diluted magnetic semiconductors (DMS) represent
an important family of materials. In an extremely quoted paper of Dietl et al., ZnO and
GaN have been predicted ferromagnetic at room temperature. Since 2000 a lot of
controversial works were published on the subject showing that these materials show
ferromagnetic behavior in function of the doping but also of the synthetic approach. A
recent theoretical work predicts that transition-metal doped zirconia can be also
ferromagnetic at room temperature in function of the metal dopant, its oxidation state and
concentration. Non-aqueous sol-gel routes are remarkably successful for the synthesis of
oxide materials. Solvent assisted synthesis and especially the “benzyl alcohol route” have
several advantages such as a low reaction temperature and a high crystallinity and purity
of the as synthesized oxides. We extended the “benzyl alcohol route” to the synthesis of
transition metal doped oxide semiconductors. This synthetic method enables the
incorporation of several transition metal dopants into oxide matrix. Here, we present the
synthesis, the characterization and the magnetic properties of doped ZnO and ZrO2
nanoparticles. The synthesis involves the reaction of inorganic precursors and benzyl
alcohol at moderated temperature and lead to high-quality nanocrystals presenting a
homogeneous distribution of the magnetic ion. Manganese doped zinc oxide as well as
manganese doped zirconia, exhibit mainly a paramagnetic behavior of the diluted spins.
In the case of cobalt doped zinc oxide, the magnetic properties are affected by the
synthesis condition, paramagnetic or ferromagnetic behavior was obtained depending on
the solvent used. The homogeneity and local environment of the magnetic ions diluted
into the matrix were characterised by high resolution TEM, electron energy loss
spectrometry and by electron paramagnetic resonance, which is a local probe sensitive to
oxidation state, local symmetry and spin-spin interactions. After providing evidence on
the homogeneity of doping and the absence of any secondary phase, the magnetic
properties of the as-synthesized nanoparticles were meticulously studied using SQUID
and VSM magnetometer.
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DESIGN AND FABRICATION OF HETEROSTRUCTURED MAGNETIC
NANOPARTICLES AND NANOPARTICLE-CRYSTALS FOR
Jian-Ping Wang, Yunhao Xu, Xiaoqi Liu, Ying Jing, Timothy Kline
Department of Electrical and Computer Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, USA; [email protected]
354
In this paper, we will first discuss the desirable properties of magnetic nanoparticles for
biomedical applications. Nanoparticles with high-magnetic moment, high-anisotropy
constant and smart functions will be emphasized. Then, we will report a newly-developed
general gas-phase method to fabricate nanoparticles with selected crystal structures and a
variety of heterostructures and use this method to fulfill the designed properties of
magnetic nanoparticles for kinds of biomedical applications. For magnetic materials,
crystal structure control is very important not only because the arrangement of bulk
atoms determines the magnetic properties but also because atoms on different crystal
surfaces have different contribution. Here we report a preparation method that can tune
the crystal structure and magnetic properties of nanoparticles and at the same time
provide materials without surface adsorbates. In this method gas phase aggregation is
used to generate nanoparticles. Crystal structure control is achieved by directly
manipulating the energy carried by nucleating atoms and growing species using
magnetron plasma as the adjustable energy source. At three different densities of plasma,
FePt nanocrystals with three different kinds of crystal structures, A1 icosahedron, A1
octahedron and L10 octahedron were prepared, respectively. High-resolution TEM
images clearly show the different arrangements of atoms and magnetic measurements
reveal that they have very different magnetic performance. These materials can be used
as different types of nanoscale magnets having the same chemical composition. The
potential applications of them are magnetic storage media, magnetic sensor and labeling
devices, as well as that for biomedical applications. The technique reported here can be
easily extended to other magnetic as well as non-magnetic nanocrystal fabrication thus to
provide a general platform for technological and fundamental study at the nanometer
scale. Heterostructured nanoparticles are highly desirable in applications such as medical
imaging, drug delivery, thermal cancer treatment and etc., which combine different
properties of the individual component structure into one single nanoparticle and have
possible enhancement of each properties. Different from the previous two-step method
used in both the chemical approach and physical vapor deposition approach, a “one-step”
method is developed to synthesize heterostructured nanoparticles direct from gas phase.
An integrated nanoparticle deposition system is used to fabricate the heterostructured
nanoparticles in this study. It has been demonstrated that a variety of heterostructures can
be produced by using the method, including core-shell, multi-core-multi-shell, dumbbell,
and sphere with nodules. The heterostructure is formed by controlling the initial
conditions of atom generating and the thermal environment in the nanoparticle source.
Results have been obtained from different materials systems including Co and Au, Fe and
Ag, FeCo and Si, and FeCo and Au/Ag/Cu. In the last part of the talk, applications and
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advantages of the synthesized water-soluable and bio-compatible high-magnetic-moment
nanoparticles will be reported in magnetic hyperthermia, MRI imaging, drug delivery and
release and bio-sensing.
Session M1 – Contributed Paper
MAGNETIC PARTICLE BASED NANOBIOMARKERS FOR SENSING
APPLICATION
Chen-Zhong Li, Nanobioengineering/Bioelectronics Lab, Department of
Biomedical Engineering, Florida International University, 10555 W. Flagler
St. Miami, Florida 33174, USA; E-mail: [email protected]
Various nanomaterials, including carbon nanotubes, metallic nanoparticles,
semiconductor nanowires, nanoscale magnetic films, and conducting biomoleculars have
emerged as candidates for new-generation sensoric chips. The innovation of using
antibody modified metallic nanoparticles (Nps) as biological sensing elopements for the
electrochemical detection of micro organisms and various toxins responds to the urgent
needs for clinic diagnosis, homeland security and biowalfare. Due to nanoparticles are
capable of forming active complexes with different type of biological substances, the
antibody-Nps hybrids can serve to selectively recognizing the binding targets. Such nano
sized particles provide a high surface-to-volume ration, increasing the density of
immobilized antibody probes, which is beneficial for a high detection signal and
sensitivity. In this report, combining MEMS technology, electrochemistry and
immunology, a sensing system based on superparamagnetic magnetic Nps or core-shell
structured magnetic Nps for quickly analysis of micro organisms will be presented. In
the sensing array system, multi micro gold electrode array are fabricated upon
polycarbonate surfaces using photolithographic processes. By guiding of magnetic biotags using on-chip generated magnetic forces to a specific electrode on the sensor chips,
the electrochemical responses rapidly reflect important information such as bacteria
motions and the type of bacteria. In addition, magnetic particles based immunosensors
allow for a rapid regeneration and exchange of the magnetic bio-tags when needed.
355
ELECTRON MICROSCOPY CHARACTERIZATION OF CHEMICAL
ORDER IN SMALL NANOPARTICLES
Richard R. Vanfleet, Department of Physics and Astronomy, Brigham
Young University, Provo, UT 84602, USA; [email protected]; Rumyana
Petrova and Kevin R. Coffey, AMPAC, University of Central Florida,
Orlando, FL 32816, USA
356
Chemically ordered intermetallic nanoparticles of FePt and similar L10 ordered alloys are
candidate materials for high-density magnetic recording media. The degree of chemical
ordering is a fundamental parameter for useful application. The chemical order
parameter (S) can be quantitatively measured by x-ray diffraction for sufficiently thick
layers but signal to noise problems hamper studies on thin films and layers of
nanoparticles. Additionally, X-rays measure large numbers of particles at once giving
186
results for an “average” particle but no information about particle to particle variation.
High Resolution Electron imaging techniques can show ordered spacings to identify
individual chemically ordered particles but do not give a quantitative measure of the
degree of ordering (S). We will present our work on using single particle electron
diffraction in conjunction with multislice simulations to extract order parameter values
from individual particles. The important computational and experimental parameters and
processes will be discussed.
QUANTITATIVE PARTICLE ANALYSIS BASED ON ELECTRON
MICROSCOPY IMAGING DATA
Ben Lich*, Jens Greiser*, Ulf Willen**, Andy Prior** and Arjen Tinke***;
*
FEI Company, Achtsteweg Noord 5, Eindhoven, The Netherlands,
[email protected]; **Malvern Instruments, Grovewood Road, Malvern UK,
[email protected]; *** Johnson and Johnson Research,
Turnhoutseweg 30, Beerse, Belgium, [email protected]
357
In pharmaceutical industry there is a growing tendency to develop less soluble active
pharmaceutical ingredients (API). In order to assure acceptable in vivo dissolution and
bioavailability, the trend is to use larger specific surface area of the active substance
leading to smaller drug particles. Since the shape of a particle can be considered as its
size manifestation in three dimensions and since the surface/volume ratio exponentially
increases with a smaller size of the particles, for sub-micron and nano-size particles the
characterization of shape becomes increasingly important. Current size measurement
techniques generally rely on an indirect measurement of the particle size, and reporting of
Particle Size Distribution (PSD) data generally occurs based on the assumption that the
particles are spherical. As pharmaceutical actives are typically obtained by crystallization
and milling processes, particles are non-spherical and hence there is a growing interest in
characterizing the accurate particle size and shape. A better understanding of the
solubility of the active ingredients will lead to improved drug formulations. In this study
we present promising results based on expanding the “seeing is believing” paradigm, i.e.,
scanning electron microscopy images are used not only for qualitative purposes, but also
for the quantitative PSD analysis of a pharmaceutical sub-micron suspension. The effects
of sample preparation, image acquisition conditions and image processing are evaluated.
In particular, the consequences related to the choice of filters, imaging vacuum mode and
detector technology will be discussed in more detail.
MAGNETIC NANOPARTICLES AND XMR-TECHNOLOGY: A
COMBINED TOOL FOR SINGLE MOLECULE DETECTION
Andreas Hütten, Inga Ennen, Camelia Albon, Ning Ning Liu, Alexander
Weddemann and Günter Reiss, Thin Films and Physics of Nanostructures,
Department of Physics, Bielefeld University, P.O. 100131, 33501 Bielefeld,
Germany; [email protected]; [email protected].
358
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A promising approach for a future diagnosis of, e.g., virus diseases is the application of
magnetoresistive sensors in lab-on-a-chip structures. This enables the production of
cheap, portable, easy-to-use and fast devices for the standard human diagnosis. Such
biosensors are based on two recently developed techniques and devices: Magnetic
markers and XMR-sensors, where XMR means either giant magnetoresistance (GMR) or
tunneling magnetoresistance (TMR). The magnetic markers are specifically attached to
the target molecules such as DNA or antibodies and can be manipulated easily by
external magnetic gradient fields. Their magnetic strayfield can be picked up by a
magnetoresistive sensor as a change of the electrical resistance which can be used for
further automated analysis. Our contribution is focused on physical aspects which play an
important role on the way to lab-on-a-chip structures: First, we will cover the
development of highly sensitive GMR- and TMR- sensors with isotropic characteristics
to optimize the magnetic interactions with the magnetic markers. Thereby, the resulting
strategy for measurements and the sensitivity of the sensor elements will be discussed.
Furthermore, concepts for the manipulation and controlled guidance of molecules
attached to magnetic markers, e.g., in fluidic channels are presented. Therefore, a
combination of suitable magnetic markers and magnetic gradient fields has been
employed.
HETEROFLOCCULATION STUDIES OF DEFORMABLE AND NONDEFORMABLE POLYMERIC PARTICLES
Hani Nur*, M.J. Snowden, V.J. Cornelius and L.S. Benée, Medway
Sciences, School of Science, University of Greenwich at Medway, Chatham
Maritime, Kent, UK, ME4 4TB; [email protected]
359
The interactions between different types of colloidal particles have been investigated with
respect to particle size, surface charge, temperature and the deformability of the particle.
The particles studied were anionic polystyrene latex (non-deformable) and deformable
particles of cationic poly (N-isopropylacrylamide) [pNIPAM]. Three different anionic
polystyrene latex dispersions, differing only in size, were mixed separately with cationic
poly pNIPAM microgel particles in different ratios. The physical state of aggregation was
observed visually and the state of aggregation was studied by turbidimetric measurements
together with SEM analysis. The heteroflocculation behaviour was investigated at two
different temperatures 25 and 50ºC, which are the temperatures below and above the
volume phase transition (VPT, ~34ºC) of the microgel particles. A temperature dependent
reversible flocculation was observed for some mixed particulate systems. Results has
shown that the observed state of aggregation or stability is the result of a complex
balance between diffusion effects (Brownian motion), electrostatic (repulsive and
attractive) forces as well as van der Waals forces—all of which are influenced by the
environment of the particles, particle-size, their relative concentrations, temperature and
surface charge density under a particular set of experimental conditions. It is also
observed that the ionic interaction between oppositely charged deformable and nondeformable particles can be manipulated by temperature or particle concentration as a
trigger to switch on or switch off the heteroflocculation mechanism which may have
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potential applications in water industry for removal of colloidal impurities. Some mixed
particulate system showed very strong irreversible aggregation behaviour which could be
exploited in the field of enhanced oil recovery.
PARTICLE OUTLIERS AND CONTAMINANTS - LOOKING FOR THE
NEEDLE IN THE HAYSTACK.
Leonardo Cinquea, S. Kim R. Williamsa, Edward E. Remsenb, Mungai
Kamitib, David Boldridgeb, Mansour Moinpourc; aDepartment of Chemistry
and Geochemistry, Colorado School of Mines. 1500 Illinois St. Golden, CO
80401, USA; bCabot Microelectronics Corporation, Aurora, Illinois; cIntel
Corporation, Santa Clara, CA, USA; [email protected],
[email protected]
360
The observed properties of material systems can be severely impacted by the presence of
low levels of outliers or undesired particles. The ability to detect these undesirable
components in an overwhelming sea of particles is an analytical challenge that impedes
property-performance studies. Ensemble methods, such as those based on light
scattering, provide average values and have insufficient resolution to discern small
differences in particle populations. We have developed a method based on field-flow
fractionation (FFF) and single particle optical sizing (SPOS). The high resolution flow
FFF stage spatially separates particles into different sizes which are counted as they flow
through the SPOS detector. The strengths of this complementary combination of
techniques are that quantitative information can be obtained, particles present in low
amounts are easily discernible, and dynamic changes in the particle population can be
measured. This presentation addresses the development of the FFF-SPOS system and its
application to colloidal and fumed silicas used for chemical-mechanical planarization
(CMP) of silicon wafers. The CMP process, universally adopted in microelectronic
components manufacturing, is based on the use of abrasive slurries for the planarization
and polishing of components surfaces. CMP utilizes a combined chemical and
mechanical abrasive action of the slurries particles on the surface to be treated. The
particle size distribution is one key to effective treatment. A careful control of the large
particle count is necessary to prevent extensive surface defects that will degrade the
performance of the microelectronic component. In collaboration with a consortium of
enterprises working in the semiconductor field, we have demonstrated the FFF/SPOS
characterization of low particle populations amidst high total particle backgrounds and
have applied the methods to CMP slurries.
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CHARACTERIZATION OF DISPERSED SYSTEMS USING
MULTIWAVELENGTH TRANSMISSION MEASUREMENTS
Maria-T. Celis1-3, Ana Forgiarini1-3, Laura Márquez3 and Luís. H. García
Rubio2; 1 Lab. Polymers and Colloids (POLYCOL), Chemical EngineeringUniversidad de Los Andes, Mérida 5101-Venezuela; 2 College of Marine
189
Science, University of South Florida, St.Petersburg- Florida, USA; 3Lab.
FIRP, Chemical Engineering- Universidad de Los Andes, Mérida 5101Venezuela; [email protected]
The stirring of a dispersed system result in the production of droplet/particle populations,
generated from the dynamic equilibrium between the breakup and coalescence
phenomena during the process, and determined primarily by the formulation and
composition variables, mixing characteristics and system preparation. The estimation of
the droplet/particle size and droplet/particle size distribution are important data, not only
because they are linked with the manufacturer process, but also they provide information
of the properties of the dispersed phase and are an important parameter affecting the
stability of the dispersion.. The information contained in the UV-Vis spectrum on the
absorption and scattering properties of the emulsions lead to the interpretation of the
spectra in terms of the particle size distribution, the particle shape and the chemical
composition of the oil and emulsifier. The aims of this research is on analyzes of
dispersed systems (i.e. macroemulsions, nanoemulsions, polymers, and suspensions), on
transmission spectrum as function of the dispersed phase concentration and
physicochemical variables. The quantitative interpretation of the transmission spectrum is
performed in the portion where no absorption is present (300-820 nm) leading to reliable
estimated of particle size populations in the range of 0.02- 20 μm. The spectroscopy
technique proposed is on the regularized solution to the inverse problem posed by the
multiwavelength turbidity equation. The particle characterization methodology is based
on a coupled sampling and dilution strategy combined with spectroscopy methods The
possibility of obtaining information from a single multiwavelength measurement makes
UV-Vis spectroscopy a powerful tool for characterization of dispersed systems.
SIZE-DEPENDENT INTRINSIC RADIATIVE DECAY RATES OF
SILICON NANOCRYSTALS AT LARGE CONFINEMENT ENERGIES
Milan Sykora*, Lorenzo Mangolini,† Richard D. Schaller*, Uwe
Kortshagen,† David Jurbergs‡ and Victor I. Klimov*; *Chemistry Division,
Los Alamos National Laboratory, MS J567, Los Alamos, New Mexico
87545, USA; [email protected]; †Department of Mechanical Engineering,
High Temperature and Plasma Laboratory, University of Minnesota,
Minneapolis, Minnesota 55455, USA; ‡Innovalight Inc., 3303 Octavius
Drive, Suite 104, Santa Clara, CA 95054, USA
362
Following the initial observation of efficient photoluminescence (PL) from porous Si,
there have been numerous reports on greatly enhanced emission efficiencies in various
types of Si nanostructures. For example, a recently developed plasma-synthesis and
organic surface passivation technique produces Si NCs with a PL quantum yield >60%.
However, the mechanism for high-efficiency PL from Si nanostructures is still under
debate. For example, “surface-state” models ascribe it to recombination of carriers
trapped at surface sites, while in “quantum-confinement” models, the PL is explained by
recombination across the fundamental nanostructure band gap. In the latter case, the
observed increase in the radiative rate is attributed to confinement-induced relaxation in
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momentum conservation, which opens an additional radiative decay channel via zerophonon, pseudodirect transitions. In the present work, we analyze the evolution of PL
spectra of Si NCs on sub-picosecond to sub-microsecond time scales using different
spectroscopic techniques. The early time PL spectra (<1 ns), which show strong
dependence on NC size, are attributed to emission involving NC quantized states. The PL
spectra recorded for long delays (>10 ns) are almost independent of NC size and are
likely due to surface-related recombination. Based on instantaneous PL intensities
measured 2 ps after excitation, we determine intrinsic radiative decay rates for NCs of
different sizes. These rates sharply increase for confinement energies greater than ~1 eV
indicating a fast, exponential increase in the oscillator strength of zero-phonon,
pseudodirect transitions. Similar size-dependent trends are observed for samples prepared
by two different gas-phase techniques, which strongly suggests that our results are not
sample-specific but rather reflect intrinsic properties of Si NCs.
SCATTERING OF EM WAVES BY SMALL MAGNETIC PARTICLES
Gautam Mukhopadhyay, Shruti Puri, Physics Department, Indian Institute
of Technology-Bombay, Powai, Mumbai 400076, India;
[email protected]
363
Scattering of electromagnetic (em) waves by scatterers in a medium having different
dielectric constant as well as different magnetic permeability may show unusual
properties. Numerous studies report unusual behavior of scattering effects by small
magnetic spheres. Recently, some experiments have reported (cf. Mehta et al., PRL 96,
127402 (2006) ), the observation of a novel effect in scattering by micron sized magnetic
spheres dispersed in a ferrofluid in the presence of an externally applied magnetic field..
It is reported that, at a critical value of the magnetic field applied to the system, the
forward scattering disappears. Under certain conditions, along with forward scattering,
back scattering is also found to disappear. To our knowledge, the theory behind those
experiments still needs to be formulated. By modeling the ferrofuid as consisting of
magnetic particles distributed in nonmagnetic medium, we describe its magnetic
properties in terms of Maxwell-Garnett theory. We then develop general theory of
scattering of em waves from ellipsoids dispersed in such a medium. In our analysis, we
take the dielectric constant as well as the magnetic permeability of the medium and the
scatterer to be different. The case of spheres in the experiments in question then follow
as a special case of our general results. We find that there is a drastic change in the
scattering pattern of the electric field if we consider the ellipsoidal particle to have nonzero magnetic susceptibility. By considering the dependence of electric and magnetic
susceptibilities on the intensity of the field, we show that the forward scattering vanishes
for a critical value of the magnetic field.
CHARACTERISING THE DISPERSION OF FINE AND ULTRA-FINE
CALCIUM CARBONATE PARTICLES IN POLYPROPYLENE
Paul G Jonesab, Yingdan Zhuc, David I Gittinsa, Jarrod R Harta, Stephen N
Kukurekab, Neil Rowsonb and David R Skuse a) Imerys Minerals Ltd, Par
364
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Moor Road, Par, Cornwall, PL24 2SQ, UK b) School of Engineering, The
University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK c)
Interfacial Analysis Centre, Oldbury House, 121 St Michael’s Hill, Bristol,
BS2 8BS, UK ; [email protected]
The previous decade has shown an increasing research interest into the formulation of a
well-dispersed mineral/polymer nano-composite but the cost-effective incorporation of
nano-scale calcium carbonate particles in non-polar polymers has had limited success to
date. Conventional polymer matrices that contain low aspect-ratio fine fillers have not
been thoroughly characterised. The high level of interest in nano-composites has resulted
in a significant number of literature and patent publications, but the challenges that face
an engineer in large-scale production are seldom addressed. This work aims to provide a
platform for further research by characterising the dispersion of fine low aspect-ratio
fillers in a conventional polymer matrix. Provided that dispersion is achieved, finer
particles of the discrete phase purportedly improve various mechanical properties,
including impact strength. This has lead to research both into improving dispersion and
reducing the average size of these dispersed particles. The concept is complicated by
particle agglomeration, the occurrence of which becomes more favourable with
increasing specific surface area. Novel treatments and production routes have been
investigated with the intention of limiting these effects. A host of mineral properties both
prior and subsequent to their incorporation within a polymeric matrix have been studied
and the existing correlations between these properties and the resulting mechanical
properties have been identified. Future work will involve researching less energyintensive routes firstly for producing minerals to the desired size specification and
secondly in the composite production stage.
ENCAPSULATED WHITE-LIGHT CdSe NANOCRYSTALS AS
NANOPHOSPHORS FOR SOLID STATE LIGHTING
Sandra J. Rosenthal,Department of Chemistry, Vanderbilt University,
Nashville Tn; [email protected]
365
Ultrasmall CdSe nanocrystals yield emit broad spectrum, pure white emission with
chromaticity coordinates of (0.324, 0.322). As such, they present an exciting possibility
in the area of solid-state lighting (SSL) technology. We have employed these
nanocrystals in prototypical SSL devices in which the nanocrystals serve as a
nanophosphor pumped by a UV LED. Thirteen dissimilar polymers were examined as
potential encapsulants for these single size nanocrystals. Of the encapsulants tested, the
most robust, color stable, and homogeneous encapsulation was obtained using a
biphenylperfluorocyclobutyl polymer. Devices utilizing the ultrasmall nanocrystal and
this polymer had a high color-rendering index of 93.
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IMPROVED SPONTANEOUS EMISSION OF A NANO-FLUOROPHORE
IN METAL NANOSHELLS WITH PLASMONIC RESONANCE
Wallace C. H. Choy1, Xue-Wen Chen1,2, Sailing He2, and P.C. Chui1;
1
Department of Electrical and Electronic Engineering, University of Hong
Kong, Pokfulam Road, Hong Kong, China; 2Centre for Optical and
Electromagnetic Research, Zhejiang University; Joint Research Centre of
Photonics of the Royal Institute of Technology (Sweden) and Zhejiang
University, Zhijingang campus, Hangzhou 310058, China;
[email protected]
366
Fluorescent nanomaterials, including organic and metallorganic dye molecules,
fluorescent proteins, II-VI and III-V compound semiconductor nanoparticles,
polymer/dye-based nanoparticles and silica/dye hybrid particles, have been the subject of
intensive research in recent years for their vast applications ranging from biomedical
therapeutics and diagnostics to information storage and optoelectronics. For fluorescence
based applications, fluorescence efficiency, i.e. the external quantum efficiency (EQE) of
the emitter, is an important issue. Due to the existence of pronounced nonradiative decay
of excitons in the nanoscale structure, low EQE is an often-observed feature. Most of the
reported strategies aim to reduce the nonradiative decay rate for improving the
fluorescence efficiency. The direct and effective approach to improve the EQE is to
increase radiative decay rate and the out-coupling efficiency since EQE is the product of
internal quantum efficiency (IQE) and the outcoupling efficiency. The enhancement of
radiative decay rate results in the Purcell enhancement of IQE. However, there are few
studies on increasing the radiative decay rate and out-coupling efficiency simultaneously
in core-shell nanoparticles to enhance the fluorescence efficiency. Here, we will address
this issue. In this paper, spontaneous emission (SE) rate and the fluorescence efficiency
of a bare fluorescing nanoparticle and the nanoparticle with a silver nanoshell are
analyzed rigorously by using a classical electromagnetic approach with the consideration
of the nonlocal effect of the silver nano-shell. The dependences of the SE rate and the
fluorescence efficiency on the core-shell structure are carefully studied and the physical
interpretations of the results are addressed. The results show that the SE rate of a bare
nanoparticle is much slower than that in the infinite medium by almost an order of
magnitude and consequently the fluorescence efficiency is usually low. However, by
encapsulating the nanoparticle with a silver shell, highly efficient fluorescence can be
achieved as a result of a large Purcell enhancement and high out-coupling efficiency for a
well-designed core-shell structure. We also show that a higher SE rate may not offer a
larger fluorescence efficiency since the fluorescence efficiency not only depends on the
IQE but also the out-coupling efficiency.
COLLOIDAL CIGS PARTICLES: A PRECURSOR ROUTE TO ULTRA
LOW COST PHOTOVOLTAICS
Matthew Panthani, Vahid Akhavan, Brian Goodfellow, Brian A.
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Korgel,Department of Chemical Engineering, Texas Materials Institute,
Center for Nano and Molecular Science and Technology, The University of
Texas, Austin, TX 78712, USA; [email protected]
Colloidal copper indium gallium selenide (and sulfide) (CIGS) nanocrystals
approximately 10 nm in diameter or less were synthesized by high temperature arrested
precipitation. The ligand chemistry turns out to be extremely important for the synthesis
of these CIGS nanocrystals, and many common ligands used for arrested precipitation of
metal and semiconductor nanocrystals do not work because they negatively impact the
reaction chemistry and yield primarily stable molecular byproducts. Deposition
strategies were then developed to achieve uniform, thick (~1 micrometer) CIGS
nanocrystal films largely free of cracks. The as-deposited films are relatively resistive
and prototype photovoltaic (PV) devices constructed from these films show only a weak
PV response. Further processing steps were developed to greatly improve the properties
of the nanoparticle films, resulting in decreased resistance, better photoresponse and
higher PV efficiencies from devices constructed with these nanoparticle-based absorber
layers.
ENHANCEMENT OF THE EMISSION OF COLLOIDAL
NANOCRYSTALS EMBEDDED IN PHOTONIC DEVICES
Luigi Martiradonna, A.Qualtieri, T.Stomeo , L.Carbone, A.Tandaechanurat,
L.Manna, S.Iwamoto, Y.Arakawa, R.Cingolani and M.De Vittorio, Scuola
Superiore ISUFI, NNL of CNR-INFM, Univ. del Salento, via per Arnesano,
Lecce, I-73100, Italy - IIS, INQIE, RCAST, University of Tokyo;
[email protected]
368
The development of photonic devices based on wet-chemically synthesized
semiconductor nanocrystals (NCs) is nowadays one of the main research topics in
international laboratories, due to their broad excitation spectra and narrow emission
bands also at room temperature, tunable optical gain from the UV to the NIR spectral
range, high photochemical stability. The insertion of these nanoemitters into photonic
crystal (PC) cavities with localized optical modes having high quality factor (Q) and
small modal volume can be exploited to develop high performing optical devices such as
single photon sources, ultra-low threshold lasers and non-linear devices. We propose the
fabrication of semiconductor nanocrystal based 2D-PC nanocavities by directly
patterning and releasing a thin membrane of a functional material composed by NCs
dispersed in a positive electronic resist. No pattern transfer from the resist to underlying
membrane layers is required, since the resist itself acts as the suspended waveguiding
layer. Therefore the optical quality of the resonating structure is only determined by a
single high-resolution lithographic step, while it is not affected by any etching process.
This can strongly improve the overall quality and repeatability of the fabricated devices,
whose measured performances match almost perfectly the expected ones inferred by the
simulation of ideal structures. This technological approach enables the enhancement and
spectral tailoring of the emission of colloidal nanocrystals with full applicability both in
the visible and the infrared spectral range, thanks to the optical transparency of the
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polymeric membrane in which the emitters are dispersed. Moreover, the flexibility of the
suspended structures can be also exploited for the fabrication of optical strain sensors and
micro-actuators.
ELECTROCHROMIC POLYMER WINDOWS
Chunye Xu, Lu Liu and Minoru Taya, Center for Intelligent Materials and
Systems, University of Washington, Seattle, WA 98195, USA;
[email protected]
369
As the economy is growing in the world, energy is being strongly demanded.
Commercial buildings in the United States use 18% of the total energy consumption each
year. Of this amount, 26% was spent on air-conditioning. Windows make up
approximately 13% of wall area in new residences and up to 50% in large office
buildings. Because of our limited access to energy on earth, energy efficient devices or
energy saving systems are urgently required. A promising technology developed to help
face this challenge is electrochromic (EC) or ‘smart’, switchable window technology. EC
polymer materials can change their optical properties reversibly under an applied
potential due to electrochemical oxidation and reduction. These windows are capable of
controlling the throughput of radiant energy, potentially greatly reducing the amount of
electricity consumed by heating and air conditioning, by allowing sun in during the
winter and blocking it during the summer. Compared with other EC windows and lenses,
organic based EC polymers used in this technology have gained popularity due to their
small energy consumption, rich color, excellent open circuit memory, long lifetime and
fast switching speeds. Additionally, ease in fabrication of large scale and flexible devices
are positive features. EC windows are composed of mutiple chemical layers including an
ion storage layer formed of nanoparticles, TiO2-V2O5. This layer plays a criticle role in
balancing the charges of an EC active layer, so as to maintain a high contrast ratio of the
device. The user can control the degree of tint, which remains after the power is turned
off (open circuit memory). ECW for architecture window applications could save space
by eliminating the need for dirt collecting shades, curtains, and blinds. Additionally, there
are applications in aircraft, automobiles, sunglasses, displays, etc.
3D FUNCTIONAL HETERONANOSTRUCTURES MADE BY
ASSEMBLY AND SHAPING OF NANOPARTICLE-FILM SYSTEMS
Nina Kovtyukhova and Tom Mallouk, Department of Chemistry, Penn State
University, University Park, PA 16802; [email protected]
370
This presentation summarizes our progress in the synthesis and characterization of high
aspect ratio inorganic and composite inorganic/organic nanostructures, and considers
perspectives of their application as building blocks for assembling nanoelectronic
circuits. Our strategy is based on shaping established particle-based thin-film devices,
such as p-n heterojunction and Schottky diodes, insulating layers, and thin film
transistors, into tube-encapsulated nanowire structures. This has been achieved by
195
combining wet adsorption methods for making thin-film devices with template
electrochemical synthesis. We have recently demonstrated the applicability of two layerby-layer (LBL) assembly techniques to template membranes with cylindrical pores and to
metal nanowire substrates. A variety of building blocks, such as semiconductor particles,
short individual single-walled carbon nanotubes, polymers, and molecular precursors, can
be alternately adsorbed one-layer-at-a-time inside the membrane pores and/or around
metal wires. Important advantages of this strategy are (i) the possibility of organizing
chemically and geometrically different blocks within a single nanostructure, (ii)
technologically simple, inexpensive and scaleable synthesis of relatively uniform
nanotubes and tube-encapsulated nanowire devices with excellent control over their
length and diameter, (iii) precise control over thickness of the electroactive tube-shell,
which is easy achievable by varying the number of adsorption cycles and by washing
between adsorption steps in order to remove weakly bound particles or molecules.
Using these synthetic strategies, insulated metal interconnects, coaxially-gated in-wire
thin film transistors, and nanowire p-n heterojunction diodes can be prepared. The latter
exhibit a rectification ratio close to that of p-n diodes prepared from single-crystal Si or
InP nanowires. Importantly, the electrical characteristics of the tube-encapsulated
nanowire devices are similar to those of large area planar thin film devices that were
prepared by similar LBL techniques. This means that nanoparticle and molecular organic
components can be introduced into the wire-in-tube structures without qualitative
changes in their electrical, and most probably, chemical properties.
A NOVEL METAL/SEMICONDUCTOR EPITAXIAL INTERFACE: SiO2
FILM CONTAINING COOKIE-LIKE Au-NiO NANOPARTICLES
SHOWING GAS SENSING PROPERTIES
Alessandro Martucci1, D. Buso1, M. Guglielmi1, M.L. Post2, G. Mattei3, P.
Mazzoldi3; 1 Dipartimento di Ingegneria Meccanica Settore Materiali,
Università di Padova, Italy [email protected]; 2 Institute for Chemical
Process and Environmental Technology National Research Council of
Canada, Ottawa, Canada; 3 Dipartimento di Fisica, Università di Padova, Italy
371
The known favorable lattice matching between Au and NiO crystals (difference between
unit cells constants reported in few hundredths of nm) made possible the growth of
peculiar cookie-like nanoparticles (25 nm mean diameter) inside a porous SiO2 film by
simply tailoring the film synthesis parameters. The unusual aggregates result from the
coupling of well distinguishable Au and NiO hemispheres, which respectively face each
other through the (100) and (200) lattice planes. High resolution TEM analysis revealed
that the twofold nanostructures show a sharp flat interface with epitaxial coherence
between the Au and NiO phases. The Surface Plasmon Resonance (SPR) bands observed
in optical absorption spectra put in evidence the effect of the atypical dielectric nature of
the media surrounding the Au aggregates. SPR bands appear to be strongly red-shifted
and modified in shape compared to typical SPR bands observed for AU NPs in solution.
Each Au aggregate faces both the SiO2 matrix (n = 1.46) and the NiO (n = 2.34) surface,
which in turn lead to the observed shifted and double-featured SPR band in absorbance
spectra. This conclusion is further confirmed by a simulated fitting of the spectra
196
obtained using the Mie relations for Au NPs immersed in a non absorbing media. The
films show noticeable and reversible change in the optical transmittance when exposed to
CO and H2, with peculiar features according to the detected species. Presence of CO does
not modify the maximum SPR band wavelength, while H2 induces a clear shift of the
overall plasmonic resonance frequencies. Moreover the absence of cookie-like aggregates
(i.e. Au and NiO as separated aggregates) emphasizes the detection of H2 in the whole
operative temperatures range (50-300°C) tested, while films with cookie structures show
a marked sensibility towards CO especially at lower operative temperatures ranges (50150°C). These observations may indicate a dielectric nature of the H2 detection
mechanism and a more pronounced catalytic character of the CO detection. The
conclusion is not trivial as in literature H2 and CO detection mechanisms are generally
related only to catalytic oxidation of the two species. Furthermore an unusual increase of
optical absorption confined around the SPR frequencies has been observed in films
containing cookie structures exposed to CO. A possible explanation could be related to
electron injection from NiO into Au in the cookie-like Au/NiO nanoparticles, thereby
increasing the number of electrons available at the Au side of the Au/NiO interface that
are involved in the catalytic oxidation of CO.
MORPHOLOGY DESIGN IN RECYCLABLE NANOPOROUS
TEMPLATES - TOWARDS HIGH-THROUGHPUT PRODUCTION OF
TAILOR-MADE NANOFIBER ARRAYS
Markus Geuss,1 Silko Grimm,1 Reiner Giesa,2 Hans-Werner Schmidt,2 Nitin
Shinge,3 Thomas Thurn-Albrecht,3 Ulrich Gösele,1 Martin Steinhart1; 1 Max
Planck Institute of Microstructure Physics, Halle (Germany); 2 Department of
Chemistry, University of Bayreuth (Germany); 3 Department of Physics,
Martin-Luther-University Halle-Wittenberg (Germany);
[email protected]
372
Arrays of aligned nanofibers and microfibers with diameters ranging from 20 to 1000 nm
consisting of tailor-made polymeric or polymer-derived materials are a promising
material platform for a broad range of applications in the fields of separation, storage, and
sensor technology. Moreover, they may serve as functional surfaces with specific wetting
properties, as artificial adhesive structures or as substrates for tissue engineering. Using
self-ordered nanoporous alumina membranes (anodic aluminum oxide, AAO) containing
hexagonal arrays of parallel nanochannels as shape-defining hard templates for the
preparation of the nanofibers, hybrid membranes containing the latter in inorganic
scaffolds are directly obtained. Infiltration of polymer melts in AAO yields nanotubes
under conditions where a mesoscopic precursor film wets the pore walls, and solid
nanorods may form by classical capillary rise. Controlling structure formation processes
such as crystallization, mesophase formation and microphase separation of block
copolymers in the two-dimensional confinement of the nanopores of the AAO hard
templates yields, for example, ferroelectric polymer nanotubes with high longitudinal
polarization, as required for polymeric sensors and actuators, or nanofibers with a tailored
mesoporous fine structure. Moreover, mechanical extraction from the AAO hard
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templates, which can thus be recycled, is a potential high-throughput access to highly
ordered arrays of released, functional nanofibers.
TEMPLATE ASSISTED HYDROXYAPATITE CRYSTALLIZATION
USING GELATIN NANOPARTICLES SYNTHESIZED VIA
MINIEMULSION PROCESS – A BIOMIMETIC APPROACH
Anitha Ethirajan,*a Ulrich Ziener,a Katharina Landfester,a Andrey
Chuvilin,b Helmut Cölfenc; (a) Instituite of Organic Chemistry III –
Macromolecular Chemistry and Organic Materials, Albert-Einstein-Allee 11,
89081 Ulm,Germany; (b) Electron Microscopy group of Material Science,
Albert-Einstein-Allee 11, 89081 Ulm, Germany; (c) Max-Planck Institute of
Colloids and Interfaces, Colloid Chemistry, Research Campus Golm, Am
Mühlenberg 1, 14424 Potsdam,Germany; [email protected]
373
The hydroxyapatite/gelatin hybrid nanoparticle has a great potential to be used as a
regenerative filler or as a scaffold for nucleation for new bone growth. These hybrid
nanoparticles offer the feasibility of being injected directly into the damaged part or as
coatings on implants to reduce the immune response or administered intravenously with
functionalization. Here, we report a novel biomimetic strategy to synthesize
hydroxyapatite inside of crosslinked gelatin nanoparticles which serve as nanoenvironment for the crystal growth in aqueous phase. The synthesis of gelatin
nanoparticles using the inverse miniemulsion technique is itself very much intriguing due
to the flexibility offered by the technique in tailoring the properties of the gelatin
nanoparticles. It can be shown that the nano-environment promotes a different growth
environment for the crystal due to the confinement inside the particle. The formation of
hydroxyapatite inside the particles follow Ostwalds rule of stages. At first an amorphous
phase is formed, which itself has a great potential to be used as a resorbable bone
substitute. This further transforms into single crystalline hydroxyapatite via an
octacalcium phosphate intermediate. The solution mediated transformation into the
hydroxyapatite phase without any calcination step is studied in detail using TEM and
XRD measurements.
EFFECTS OF SURFACE IMPRINTING ON THE SELECTIVITY
ORGANOSILICA SORBENTS FOR PRECONCENTRATION
Michael A. Markowitz, Scott A. Trammell , Mazyar Zeinali, Brian Melde,
Paul Charles, and Anne Kusterbeck, Code 6900, Naval Research Laboratory,
Washington, DC 20375; [email protected]
374
Preconcentration allows the collection of enough sample mass to obtain detectable
signals from a sensor array. Efficient preconcentration materials offer the potential for an
ultra-sensitive sensor suite with rapid response time for the detection of explosives and
other targeted molecules in field-deployable instruments. We are interested in developing
robust sorbent materials for preconcentration that will selectively collect, concentrate,
retain and detect illicit materials with the intent on improving the sensor response times
198
and limits of detection by several orders of magnitude in complex military environments.
The ability to rapidly concentrate and detect materials without being in close proximity to
the suspected target is a current gap in the capability of today’s systems. The
development of new materials is key to trace detection of chemical species and will
provide additional stand−off distance for detection. Using template directed molecular
imprinting, we have engineered organosilicas with selectivity for TNT and
organophosphonates, rapid adsorption−desorption kinetics, sensitivity, high stability,
resistance to fouling, and adsorption capacities much greater than those of other sorbents.
In addition, the ability to fabricate these materials as powders and thin films makes them
suitable for in use in multiple sensor configurations. This presentation will focus on using
mesoporous organosilicas for rapid pre-concentration and extraction of TNT for
electrochemical analysis. The relative effects of the benzene and diethylbenzene bridged
organic-inorganic polymers on electrochemical response and desorption behavior and, the
effect of template directed molecular imprinting on TNT adsorption from contaminated
soil extracts will be discussed.
EXPLORING NANOSTRUCTURED MATERIALS BY FIBER-DRAWING
NANOMANUFACTURING
Zeyu Ma, Yan Hong, Chaoming Wang, Liyuan Ma, Ming Su, NanoScience
Technology Center, Department of Mechanical, Materials and Aerospace
Engineering, Orlando, FL 32826, USA; [email protected]
375
We have developed a novel technique for the mass production of ordered nanomaterials
using fiber-drawing nanomanufacturing (FDN). In this method, the powders or a rod of a
suitable material are filled in a matching glass tube, which is drawn into fibers at high
temperature. These fibers are cut to short pieces of equal length, and stacked to form a
bundle for the next drawing. By repeating the draw-cut-stack process, the diameter of the
filling materials is reduced stepwise. The method can control the diameter, length and
inter-feature spacing with high production yield and high level of manufacturability. We
have made vertically aligned long nanowires of alloys, semiconductors, glasses, and
inorganic materials, as well as microchannel arrays etc. The novel materials are being
explored as novel substrates for energy conversions, biomolecular separation and
analysis, and novel encapsulation strategy for other functional materials.
METAL NANOPARTICLE PLASMONS INTERACTING WITH CHIRAL
MOLECULES
Itai Lieberman, Gabriel Shemer, Tcipi Fried, Edward Kosower and Gil
Markovich, School of Chemistry, Tel Aviv University, Tel Aviv 69978,
Israel; [email protected]
376
Two issues related to silver nanoparticles interacting with chiral molecules will be
presented: 1. Colloidal Ag nanoparticles coated with L-glutathione attached to bimane
chromophores were studied by absorption, circular dichroism (CD) and fluorescence
spectroscopies. The absorption and CD were resonantly enhanced via Ag surface
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plasmons by two orders of magnitude. The wavelength and particle size dependence of
the enhancement indicated that the electromagnetic "antenna" effect was in action, as
found in other surface enhanced optical phenomena. 2. The formation of chiral silver
nanoparticles when deposited on DNA templates was observed by CD spectroscopy.
Several experimens designed to better understand the mechanism leading to this effect
will be presented.
SYNTHESIS AND APPLICATION OF DOPED CARBON NANOTUBES:
NEW MATERIALS WITH ENHANCED PROPERTIES
Mauricio Terrones; [email protected]
377
ABSTRACT UNAVAILABLE
SYNTHESIS, DISPERSION AND CHARACTERISTICS OF
NANOPARTICLE-BASED RESISTS FOR DROPLET PRINTING
Horng-Show Koo1,* and Mi Chen2; 1 Department of Optoelectronic System
Engineering, Minghsin University of Science and Technology, Hsinfeng
Hsinchu 304 Taiwan, R.O.C.; 2 Department of Materials Science and
Enginnering, Minghsin University of Science and Technology, Hsinfeng
Hsinchu 304 Taiwan, R.O.C.; [email protected]
378
We demonstrate the synthesis, dispersion and characteristics of the nanoparticle-based
photosensitive resists. The size-controlled synthesis of organic resist with particles can be
attained by chemical and mechanical processing with solvent and promoters. Effects of
particle size of pigments in resists on optical, chromatic, and fluidic properties have been
observed and measured. The smaller particle size with the range of nanometer in resists is
facilitated to the better of droplet ejection from nozzle and thin film formation on glass
substrates. The size-controlled synthesis of resist inks with reddish pigments in
nanometer exhibits better characteristics of jetting, wetting and curing, and can be
significantly used to fabricate color filter by droplet printing process. The transmittance
of the prepared monochrome color filters remarkably increase with decreasing particle
size of reddish pigments, while color chromaticity of color filters increases within
optimum range of pigments particle size in nanometer. The relationship between
wavelength and transmittance of organic photosensitive resists with nano-particle reddish
pigment, indicating the dependence of spectral shift in wavelength on pigment size in
nanometer. Similarly, greenish and bluish pigments have the same behavior in optical,
chromatic, and fluidic properties.
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NANOSCALE HOLLOW SPHERES: SYNTHESIS AND PROPERTIES
Claus Feldmann, Institute of Inorganic Chemistry, University of Karlsruhe
(TH), D-76131 Karlsruhe, Germany; [email protected]
379
Advanced nanostructured materials are of fundamental interest in chemistry and materials
science. To this concern, nanorods, nanowires and nanotubes have gained significant
importance in recent years. In comparison to these structures knowledge on nanoscale
hollow spheres is much more limited. Nevertheless, certain applications such as
nanocontainers, drug delivery, high-surface materials for catalysis and gas adsorption as
well as structural building units for ultrasonic imaging or for low-weight materials have
been intensely discussed already. State-of-the-art strategy to realize nanoscale hollow
spheres is based on a solid core, on which in a first step a shell is precipitated. As a
second step, the core/template is removed by a suited etching process. This strategy
requires monodispersed and non-agglomerated templates. Here, colloidal polymer
lattices, silica or gold particles have been applied most often. For several issues (e.g.
container functionality, drug delivery) the solid template, its removal and a subsequent
refilling of the container is disadvantageous. A much higher flexibility in synthesis and
application would be possible with liquid cores/templates. In this study, hollow spheres
are realized via a w/o (water-in-oil) microemulsion, without applying a solid template.
HR-TEM images show ellipsoidal particles with outer diameters of 20 nm to 50 nm and a
wall thickness of 4 to 10 nm. HR-TEM images also exhibit the sphere wall normally to
be highly crystalline. The presentation will focus on the synthesis and characterization of
nanoscale hollow spheres. Oxide-type as well as metal-type spheres will be shown.
Furthermore, first aspects addressing physical properties and relevant features of
application will be discussed.
OPTICAL FABRICATION OF HOLLOW AND CORE-SHELL METAL
NANOSPHERES
Seol Ji Kim, Chil Seong Ah, Jong-Yeob Kim and Du-Jeon Jang, School of
Chemistry, Seoul National University, NS60, Seoul, 151-742, Korea;
[email protected]
380
A hollow platinum nanosphere has been fabricated by excavating the core silver metal of a
Ag@Pt core-shell nanoparticle optically. The surface-plasmon resonances of the shell platinum
metal were excited with picosecond laser pulses of 1064 nm. Thermalized photon energy
induces silver to melt and effuse through the shell rapidly, producing a smooth hollow platium
nanosphere. The mutual transposition of the core and the shell of a Au@pt core-shell
nanosphere has also been obtained by employing picosecond laser pulses to excite the surfaceplasmon resonances of platinum. The thermalized energy of the plasmon resonances makes the
core metal of the gold melt earlier than the shell metal of platinum because of melting
temperature differences and causes the gold to soak out of the core to the surface of the
nanosphere. A new reversed core/shell Pt@Au core-shell nanosphere is formed with further
irradiation.
201
SYNTHESIS AND CHARACTERIZATION OF ECCENTRIC TITANIASILICA CORE-SHELL AND COMPOSITE PARTICLES
Ahmet Faik Demirors, Alfons van Blaaderen and Arnout Imhof, Debye
Institute for NanoMaterials Science, Utrecht University, Utrecht, 3584CC,
The Netherlands; [email protected]
381
We describe a novel method to synthesize colloidal particles with an eccentric core-shell
structure. First, titania-silica core-shell particles were synthesized by silica coating of
porous titania particles under Stober conditions. We can control access of silica to the
pores in the titania, allowing us to produce either core-shell or composite particles.
Calcination of the core-shell particles gives unique eccentric core-shell structures, due to
extensive shrinkage of the highly porous titania core with respect to the silica shell.
However, when the titania particles are silica treated prior to drying they result in
composite titania-silica spheres. Both structures are very interesting: composite particles
are important for catalysis, coatings and photonics and eccentric core-shell particles are
increasingly receiving interest for their potential applications especially in size-selective
catalysis and photonics.
PRODUCTION, GROWTH MECHANISM, AND APPLICATIONS OF
CORE-SHELL IRON/CARBON NANOPARTICLES
Kuo Chu Hwang, Department of Chemistry, National Tsing Hua University,
Hsinchu, Taiwan; [email protected].
382
Well graphitized core-shell iron/carbon nanoparticles (Fe@CNPs) were produced via an
unprecedented "microwave arcing" process from both solid metallocene precursors and in
organic solutions without co-formation of carbon nanotubes. Fe@CNPs were wellcharacterized by various spectroscopic measurements. Saturation magnetization
measurement shows that the as-produced core-shell Fe@CNPs are ferromagnetic in
nature with a coercivity value of ~ 115 Gauss. Pre-synthesized Co nanoparticles were
used as templates for the growth of graphene shells in toluene-C60/70 solutions. Via acid
etching and removal of the central core Co nanoparticles, hollow carbon nanoparticles
could be obtained. Further thermal annealing by focused microwave irradiation leads to
merging of small core-shell metal/carbon nanoparticles into large ones, as well as
conversion of body centered cubic (bcc) α-Fe to face centered cubic (fcc) γ-Fe. The
possible growth mechanisms will be discussed. Fe@CNPs were surface functionalized to
have either carboxylate or amine functionalities with a water solubility of ~ 500 mg/L
and without losing the magnetic properties. The distribution of surface grafted oligomers
indicates that the chemical reactivity of the outmost graphene shell is not the same at
different locations, with highly strained regions having higher reactivity than less curved
regions. Core-shell Ni/ or Co/carbon nanoparticles can also be prepared in a similar way.
202
MAGNETIC NANOPARTICLES FROM METALLORGANIC
PRECURSORS
Serena A. Corr, Renata Tekoriute, Alexios P. Douvalis, Munuswamy
Venkatesan, Robert D. Gunning, Peter D. Nellist and Y. K. Gun’ko, School
of Chemistry, Trinity College, University of Dublin, Dublin 2, Ireland;
[email protected]
383
The main aim of our research is to develop new iron oxide based nanomaterials with
broad range of potential applications. Here we report an organometallic approach using
new metallorganic precursors for the preparation of magnetic iron oxide based
nanocomposites. The heterometallic Fe(II) alkoxide [(THF)NaFe(OtBu)3]2 was employed
as an iron source for the synthesis of magnetite nanocrystals, which were produced using
controlled hydrolysis and ultrasonic treatment. The resulting nanocrystals have been
analyzed and a 3-D contour plot generated, which gives a quick guide to the conditions
necessary to produce particles of a required size. Sol-gel one step processing of the
iron(II) alkoxide [Fe(OBut)2(THF)]2 and tetraethyl orthosilicate (TEOS) at various ratios
afforded new silica - iron oxide magnetic nanocomposite materials, ranging in shape
from nanocrystals to nanorods depending on percentage of TEOS added. The presence of
a silica shell around the nanoparticles improves their stability, magnetic characteristics,
biocompatability and provides sites for further functionalisation. The nanocomposites
have been investigated by FTIR and Raman spectroscopy, X-ray diffraction, 57Fe
Mössbauer spectroscopy, magnetization measurements, transmission electron microscopy
(TEM), scanning transmission electron microscopy (STEM) and energy dispersive X-Ray
(EDX) analysis. These magnetic nanocomposite materials might have a number of
potential applications in biotechnology, medicine (e.g. as magnetic fluids for MRI),
catalysis and magnetic storage.
SYNTHESIS, CHARATERIZATION AND ASSEMBLIES OF GOLD
NANORODS AND COPPER NANOCRYSTALS
Yonglin Liu and A. R. Hight Walker, Optical Technology Division, Physics
Laboratory, National Institute of Standards and Technology (NIST),
Gaithersburg, MD 20899, USA; [email protected]
384
Two colloidal nanoparticle solutions have been produced and studied; gold nanorods and
copper nanocrystals. Gold nanorods have been explored for biological and medical use
as optical contrast agents in two-photon luminescence diagnostic imaging, and
photothermal therapy of cancer cells. A persistent challenge limiting their applications is
the reproducibility of the chemical synthesis. Our research has enable gold nanorod
production with high yield and uniformity of both size and shape, via a colloidal, seedmediated, and surfactant-assisted method. 2-D ordered structures of the nanorods are
self-assembled during evaporation of solvent on a substrate, while the presence of
organic molecules such as homocysteine, glutathione, and glucose facilitates other
assemblies. Chemical-induced transverse overgrowth of gold nanorods leads to the
formation of peanut-shape nanocrystals. Secondly, copper nanoparticles have multiple
applications due to their catalytic, electrochemistry, magnetic and optical properties. Our
203
approaches to the synthesis of crystalline Cu nanoparticles will be presented, both
aqueous and organic solvents procedures. By using glucose as a nontoxic and renewable
biochemical reducing agent in aqueous solutions, the reductive reactions from Cu(II) to
Cu(0) are found to be finished in just half an hour at the low temperature of 60 °C in the
presence of poly-vinylpyrrolidone. The experimental results show the nanoparticles to be
crystalline and mainly composed of face-centered cubic Cu with a fairly narrow size
distribution (50-200 nm). Furthermore, synthesis of Cu nanocrystals, especially Cu
nanorods, produced in organic solvents involving manipulation of reaction temperatures
and time in the presence of amine and acid as capping agents will also be presented. All
nanoparticles are characterized using TEM, HR-TEM, XRD, and UV-visible
spectroscopic techniques. The mechanistic aspects of particles size control and shape
formation will also be discussed.
MAGNETIC BEHAVIOR OF MANGANESE OXIDE NANOPARTICLES
OBTAINED BY THERMAL DECOMPOSITION OF SOL-GEL DERIVED
OXALATES
Subhash Thota, Bhagwati Prasad and Jitendra Kumar*; Materials Science
Programme, Indian Institute of Technology Kanpur, Kanpur-208016, India;
[email protected]
385
Among the transition metals, manganese is complex but interesting because it exhibits
many oxidation states and form different oxides having wide range of technological
applications, viz., catalysis, ion exchange, molecular adsorption, dry cells, varistors, high
density magnetic storage media, solar energy conversion, etc. However, the behavior of
manganese oxides in nanoscale has been explored in the recent past with vigor to
understand them fundamentally and to determine their full industrial potential. So, an
effort has been undertaken here to study the formation, morphology and magnetic
properties of nanoscale manganese oxide particles. For this, the oxalate powder has been
first synthesized by sol-gel process, using manganese acetate tetrahydrate and oxalic acid
as precursors and ethyl alcohol as solvent, and dried at 80˚C for 24h. The product
essentially contains MnC2O4.3H2O with orthorhombic crystal structure (lattice
parameters a = 10.524 Å, b = 6.614 Å, c = 9.769 Å, Z = 4) and some anhydrous oxalate
(α-MnC2O4). The dried powder on calcination at 300oC for 2h in air form hollow
rectangular parallelopiped bars of nearly square base. But, decomposition at 500˚C in air
produces Mn2O3 nanoparticles with Mn3O4 and Mn5O8 as secondary phases - displaying
morphology of inter connected beads or clusters made up of tiny spherical particles
(diameter ~30-40nm). The temperature dependent magnetic susceptibility (χ) data reveal
a) antiferromagnetic behavior of Mn2O3 and Mn5O8 (Néel temperature TN being 79K and
130K, respectively), b) ferromagnetic character of Mn3O4 (Curie temperature TC~55K),
and c) bifurcation in (χ-T) curves under zero field cooled (ZFC) and field cooled (FC)
conditions. On the contrary, dried sol-gel product yields mainly MnO with some Mn3O4
on decomposition at 500˚C for 2h in nitrogen ambient. The values of blocking
temperature (TB) of Mn3O4 for the above two cases are 40 and 45K, respectively and
these are attributed to different average particle size; the corresponding magnetic
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susceptibility values are 2.52 and 0.67 emu/g.Oe, respectively. The results suggest that a
small quantity of Mn3O4 is invariably present and gets confirmed by susceptibility data
only below 50K when that turns ferromagnetic. Obviously, it is difficult to avoid the
formation of Mn3O4 in the preparations. Further, the initial product on calcination at
1100˚C for 4h forms pure Mn3O4 (body centered tetragonal phase, a~5.77Ǻ, c~9.45 Ǻ)
without any impurity and displays superparamagnetic behavior with blocking
temperature TB = 30K, magnetization at TB = 16.62 emu/g and TC = 50K.
MONOFUNCTIONAL GOLD NANOPARTICLES PREPARED FROM A
NONCOVALENT INTERACTION-BASED SOLID PHASE
MODIFICATION APPROACH
Xiong Liu, Qiu Dai, Jianhua Zou and Qun Huo*; NanoScience Technology
Center, Department of Chemistry, Department of Mechanical, Materials and
Aerospace Engineering, University of Central Florida, 12424 Research
Parkway Suite 400, Orlando, Florida 32826, USA; [email protected],
[email protected]
386
We demonstrate here a solid phase reaction approach towards monofunctional gold
nanoparticles using a non-covalent interaction-based ligand immoblization method.
Recently our group developed a "catch-and-release" mechanism for controlled chemical
functionalization of nanoparticles. In our previous work, bifunctional thiol ligands to be
attached to gold nanoparticles were first immobilized onto a polymer support by covalent
chemical bonds. In the work reported here, bifunctional thiol ligands, 11mercaptoundecanoic acids, were immobilized to positively charged silica gel and Rink
resin through electrostatic interactions. After a one-to-one place exchange reaction
between the alkanethiolate-protected gold nanoparticles and the polymer-bound
bifunctional thiol ligands, monocarboxyl gold nanoparticles were obtained as the major
product by cleaving off from the polymer support under mild conditions. This
modification of synthetic procedure greatly reduced the cost and time needed for the solid
phase monofunctionalization of nanoparticles, and also extended the range of
monofunctional nanoparticles that may be prepared from this solid phase approach.
INORGANIC/ORGANIC COMPOSITE MICROSPHERES WITH
TEMPERATURE SENSITIVITY
Haruma Kawaguchi, School of Science & Technology, Keio University
Hiyoshi, Yokohama 223-8522, JAPAN; [email protected]
387
Among several methods to prepare inorganic/organic composite microspheres, ‘in-situ
inorganic nanoparticle formation in polymeric microsphere’ was focused on in this paper.
First, poly(N-isopropylacrylamide) (PNIPAM) microgel was prepared via precipitaion
polymerization in an aqueous medium. At this time, some functional monomers were
copolymerized to give functional groups (F) into the PNIPAM microgel. The F’s such as
amino group and sulfonic group played a role to invite the precursor of inorganic
205
nanoparticles. After the precursor diffused in the microgel, reduction or oxidation was
carried out for in-situ nanoparticle formation. Thus, the distribution of nanoparticles
could be controlled by the distribution of functional groups in the microgel. When gold
nanoparticles embedded in PNIPAM microgel, the microgel dispersion had color which
was originated by surface plasmon resonance and the color changed with temperature.
When titania nanoparticles were embedded in the microgel, the photo-catalytic ability of
composite microspheres was controlled by temperature.
SYNTHESIS, CHARACTERIZATION AND PHASE TRANSITIONS OF
SMALL, SMART MICROGEL PARTICLES
Lise Arleth,1* Xiaohu Xia, 2† Rex P. Hjelm,1 Jianzhong Wu,3 and Zhibing
Hu2; 1 Manuel Lujan Jr. Neutron Scattering Center, H805, Los Alamos
National Laboratory, Los Alamos, NM 87545. 2 Departments of Physics and
Chemistry, University of North Texas, Denton, TX 76203. 3Department of
Chemical and Environmental Engineering, University of California,,
Riverside, CA 92521. * present address: University of Copenhagen,
Copenhagen, Denmark.. † present address: Wm. Wrigley, Jr. Co., Chicago,
IL, USA; [email protected]
388
We report the synthesis and characterization of small temperature responsive microgel
particles of potential use in drug delivery and other applications where temperature
responsive release is required. Monodispersed poly(N-isopropylacrylamide) (PNIPAM)
nanoparticles, with the hydrodynamic radius less than 50 nm at room temperature, were
synthesized in the presence of a large amount of emulsifiers. These microgel particles
undergo a swollen-collapsed volume transition in an aqueous solution when the
temperature is raised to around 34°C. The volume transition and structure changes of the
microgel particles as a function of temperature were probed using laser light scattering
and small angle neutron scattering (SANS) with the objective of determining the small
particle internal structure and particle-particle interactions. Apart from random
fluctuations in the cross linker density below the transition temperature, we found that,
within the resolution of the experiments, these particles had a uniform radial cross-linker
density on either side of the transition temperature. This result was in contrast to
previous reports on the heterogeneous structures of larger PNIPAM microgel particles,
but in good agreement with recent reports based on computer simulations of smaller
microgels. The particle interactions changed across the transition temperature. At
temperatures below the transition, the interactions are described by a repulsive interaction
far larger than that expected for a hard sphere contact potential. Above the volume
transition temperature, the potential was best described by a small, attractive interaction.
Comparison of the second order osmotic virial coefficient from static laser light
scattering at low concentrations with similar values determined from SANS at 250-times
greater concentration suggested a strong concentration dependence of the interaction
potential.
206
MICRO- AND NANOSPHERE CROSSLINKED HYDROGELS WITH
HIGH MECHANICAL STRENGTH AND SPECIAL OPTICAL
PROPERTIES
Ting Huang, Xiaonan Kou, Kexin Jiao, Changcheng He and Huiliang Wang,
College of Chemistry, Beijing Normal University, Beijing 100875, P.R.
China; [email protected]
389
Hydrogels are three-dimensional polymer networks swollen with a large amount of water.
However, hydrogels made from both synthetic and natural materials are usually
mechanically weak, thereby strongly impeding their practical applications, especially
biomedical applications. There is currently a widespread interest in developing new types
of hydrogels with high mechanical strength. We developed a new way to fabricate
hydrogels with with a new and well-defined network structure and high mechanical
strength. In this method, macrmolecular microspheres (MMS) or nanoshperes (MNS)
were used as the key building blocks. Emulsions containing MMS or MNS were
irradiated with 60Co-γ rays in oxygen atmosphere and thus peroxy groups were formed on
their surfaces. Then a hydrophilic monomer was added into the emulsion, followed by
bubbling the mixture with nitrogen to remove oxygen. When heated, the peroxides
decomposed to form free radicals which initiated the grafting polymerization. Physical
entanglement and chemical bonding of the grafted polymer chains led to the gelation of
the solution. The macromolecular microsphere (or nanosphere) crosslinked (MMC or
MNC) hydrogel can effectively dissipate the mechanical stress on it, and thus has
extremely high mechanical strength which is usually several tens to several hundreds
times of that of normal structure hydrogel. The concentration of MMS or MNS,
irradiation time, monomer concentration, and reaction temperature are critical for the
successful synthesis of MMC and MNC hydrogels. These factors also affect the final
mechanical properties of the hydrogels. The hydrogels with a 90% water content could
withstand compressive stresses over 10 MPa or more. Some of the hydrogels could
almost completely recover their original shapes even after an extremely high strain
(99.7%) in compression tests. The MNC hydrogels show special optical properties. Their
colors vary with MNS solid content and monomer concentration. This method may
become a general one for hydrogel synthesis due to its broad choice of polymeric
materials and monomers. The hydrogels may be used in tissue engineering and other
biomedical applications.
EFFECTS OF ENERGY ON THE NUCLEATION OF DRUG
NANOPARTICLES UNDER HIGH SUPERSATURATION
Hsien-Hsin Tung, Lei Wang, Santipharp Panmai, Mike Riebe;
Pharmaceutical Research, Merck Research Laboratories, West Point, PA
390
Rapid precipitation under high supersaturation is a proven technique to generate
nanoparticles for improvement of dissolution rate of water-insoluble compounds. In
essence, rapid precipitation consists of two stages. The first stage is the generation of a
uniform, clear, unstable and highly supersaturated solution. For this stage, significant
207
progress has been made in characterizing the mixing requirement to create such a
solution. The second stage is the formation of particles under high supersaturation. The
primary mechanism is spontaneous nucleation under supersaturation which determines
the particle size. Therefore, the key parameter is degree of supersaturation. However,
little or no attention has been given to evaluate the impact of energy application on
particle size at this stage. The current study demonstrates the impact of energy
application on particle size at the second stage. We show that particles can be generated
effectively below 400 nm using this approach under the conditions investigated. This
finding contrasts sharply to results where no energy is applied at the second stage and
only particles > 1 um are generated under high supersaturation. While additional energy
can be applied after the second stage to reduce microparticles to nanoparticles, it is
shown that the amount of energy spent is much higher than the case where energy is
applied during the second stage. A hypothesis on the fundamental mechanism responsible
for the difference is presented.
NANOPARTICLE LATEXES FROM REACTIVE IONIC LIQUID
SURFACTANTS
Dustin England, Feng Yan, and John Texter, Coatings Research Institute,
Eastern Michigan University, Ypsilanti, MI 48197, USA; [email protected]
391
Reactive ionic liquid surfactants based on an imidazolium headgroup and a reactive
acrylate in the tail group have recently been introduced to prepare interesting solvogels
and reversibly porating materials by using bulk microemulison polymerization.
Thermally initiated co-polymerization of surfactant and methyl methacrylate in
microemulsion domains predominantly populated by oil-in-water nanodroplets yields
nanolatexes substantially smaller than latexes obtained by nonreactive surfactant
homologues. We demonstrate the formation of nanolatexes approximately 20 nm in
diameter with yields of the order of 50%. These latexes can also be used as transparent
film formers and binders, and they also are very stable in high levels of indifferent salt,
indicating that the primary mechanism of stabilization in aqueous systems is steric.
Precipitation or coagulation by molar levels of bromide is characterized, as is
destabilization by hexafluorphosphate and tetrafluoroborate ions at lower concnetrations,
due to binding equilibria with the imidazolium group.
THERMAL GELATION OF OIL-IN-AQUEOUS CURDLAN EMULSIONS
Tomoaki Hino, Koichi Inoue, Hisao Oka, The College of Pharmacy, Kinjo
Gakuin University; 2-1723 Ohmori, Moriyama, Nagoya 463-8521, Japan;
Yoshiho Ogura, Saori Ohchi, Saburo Shimabayashi, Faculty of
Pharmaceutical Sciences, The University of Tokushima, 1-78-1 Sho-machi,
Tokushima, 770-8505, Japan; [email protected]
392
Curdlan, i.e., β-1, 3-D-glucan, forms gel by heating of its aqueous suspension. Vitamin E
was emulsified in 3-7 w/v% curdlan aqueous suspension containing 1-7 w/v% HCO-60.
The resultant suspension was heated at 70ْ C for 5 min, resulting in gel. The volume
208
fraction of oil phase was 0.1-0.3. Effects of preparation conditions on the physical
properties of gel were investigated. Young’s modulus and crushing stress of the gel were
measured with a curd tension meter. The release of vitamin E from the gel was evaluated
with the rotational basket method. Increase in the concentration of curdlan yielded the
increase in Young’s modulus and crushing stress. Vitamin E release was prolonged and
syneresis was suppressed with increase in the concentration of curdlan. Increase in the
concentration of HCO-60 yielded the decrease in Young’s modulus and crushing stress.
Vitamin E release and syneresis were accelerated with increase in the concentration of
HCO-60. These results are due to the reduction of the droplet size and consequent
increase in the total surface area of the droplets. Increase in the volume fraction of oil
phase yielded the decrease in Young’s modulus and crushing stress. Droplet size
increased and vitamin E release was prolonged with increase in the volume fraction.
SYNTHESIS AND CHARACTERIZATION OF DNA MESOSPHERES AS
DRUG DELIVERY CARRIERS FOR INTRATUMORAL
CHEMOTHERAPY
Iris V. Schumacher1,3, Karly A. Jacobsen1,3, and Eugene P. Goldberg1,2,3;
1
Department of Materials Science & Engineering, 2Department of Biomedical
Engineering, 3Biomaterials Center, University of Florida, PO Box116400,
Gainesville, FL 32611-6400, USA; [email protected]
393
Conventional cancer chemotherapy results in systemic toxicity which severely limits
effectiveness and often adversely affects patient quality of life. There is a need to find
new drugs and delivery methods for less toxic therapy. Previously reported DNA
complexing studies with chemotherapy drugs suggest unique opportunities for DNA as a
drug carrier. The objective of the studies reported here was an investigation devoted to
the synthesis and evaluation of novel DNA-drug nano-mesospheres (DNA-MS) designed
to be drug carriers for localized chemotherapy via intratumoral injection of drug loaded
DNA-MS dispersions. DNA-MS were prepared by a modified steric stabilization method
with glutaraldehyde crosslinking originally developed in our lab for albumin MS. In
addition, a novel ionic crosslinking method was developed using gadolinium trivalent
cations via the DNA phosphate groups. Covalent and ionic crosslinked DNA-MS
syntheses yielded 50nm to 5μm smooth spherical particle morphology with relatively
narrow process controlled size distributions. In aqueous dispersions, up to 200% swelling
was observed depending on crosslink density; with dispersion stability for more than 48
hours. DNA-MS containing 12% (w/w) mitoxantrone were prepared for the first time by
drug loading during the DNA-MS synthesis. Loading with methotrexate (9% w/w) and
5-fluorouricil (5% w/w) was similarly achieved. In vitro drug release from DNA-MS
was measured for up to 35 days in phosphate buffered saline by a minimum sink release
test. The effect of gadolinium crosslink concentration on mitoxantrone release was
evaluated at gadolinium molar equivalences in the range 20% to 120%. The most highly
crosslinked DNA-MS exhibited the most prolonged drug release. The drug efficacy of
mitoxantrone loaded DNA-MS was evaluated in vitro using a murine Lewis lung
carcinoma cell line. A significant cytotoxic response was found at mitoxantrone doses as
209
low as 1ppm. Drug release properties, DNA biodegradability, and observed cancer cell
cytotoxicity of drug loaded DNA-MS suggest that they may prove useful for intratumoral
chemotherapy.
BENIGN NANOPARTICLES FOR BIOMEDICAL APPLICATIONS
Wolfgang Sigmund, Yi-Yang Tsai, and Chris Woan, Department of
Materials Science and Engineering, University of Florida, Gainesville, FL;
[email protected]
394
Cerium oxide (CeO2) nanoparticles have been proposed as effective free radical
scavengers in a variety of cellular systems. It is our hypothesis that introduction of such
nanoparticles to islets prolongs their viability and improves their function by scavenging
reactive oxygen species (ROS). Applying a novel reverse micelle method we have
synthesized citrate-coated CeO2 nanoparticles that are well dispersed, highly crystallized
and measure 3.7nm. Furthermore, they are stable in an aqueous system for an extended
period of time. We will present a materials approach based on nanoparticles to reduce the
free radical concentration in cells to healthier levels and thus offer increased longevity.
We have demonstrated that free radical scavenging of CeO2 nanoparticles is a catalytic
reaction, which is driven by the presence of oxygen vacancies in the catalyst. We will
present the synthesis and characterization of doped ceria based nanoparticles and
quantum dots, their scavenging efficiency and traceability in cells. We use a yeast model
to demonstrate improvements towards longevity.
PEPTIDE NANOPARTICLES AS A PLATFORM FOR VACCINE DESIGN
Peter Burkhard, Institute of Materials Science, University of Connecticut,
Storrs, CT 06269, USA; [email protected]
395
We describe the structure-based design of a novel type of nanoparticles with regular
polyhedral symmetry and a diameter similar to small viruses, which self-assemble from
single polypeptide chains. The computer designs are verified by structural and
biophysical analyses including electron microscopy, analytical ultracentrifugation, CDspectroscopy, and dynamic light scattering. Such nanoparticles with regular polyhedral
symmetry represent an ideal repetitive antigen display system. Surface proteins of
pathogens or fragments of such proteins can easily be engineered into the peptide
sequence of the nanoparticle. Notably, the surface proteins of enveloped viruses contain a
trimeric coiled-coil sequence essential for their cell penetration mechanism. For example,
by extending the trimeric coiled-coil of the nanoparticle by the respective coiled-coil
sequences of HIV, influenza, Ebola, or another enveloped virus, a subunit vaccine against
these viruses can be designed. Since the nanoparticles are composed of small protein
oligomerization domains they are easy to synthesize by standard recombinant E. coli
protein expression systems. The vaccines can be produced in one single manufacturing
process without the need of any additional chemical modifications and, as opposed to
most virus like particles, they are stable without the need of DNA packaging inside.
210
MOLECULAR ORGANIZATION OF DRUG CARRIER POLYMERIC
NANOPARTICLES
Adriana R Pohlmann, Eliezer Jager, Cristina G. Venturini, Alessandro
Jager, Fernanda Poletto and Sílvia S Guterres, Instituto de Química and
Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto
Alegre, 91501-970, Brazil; [email protected]
396
Nanocapsules are submicrometric drug carriers widely studied in the past 20 years.
Environment sensitive fluorescent polymers were used to prepare nanocapsules with the
objective of verifying the molecular composition of their particle/water interface. The
polymer is restricted at the oil/water interface forming a wall, which interacts with both
inner and outer pseudo-phases at the same time. Then, to establish a quantitative
correlation between the drug permeability and the polymer concentration in the
nanocapsules, an indomethacin ester derivative was used as lipophilic model to simulate
a perfect sink condition of release. After increasing the polymer concentration (0 to10
mg/mL), the concentration of particles in suspension was constant, and the indomethacin
ester release was delayed. The ester diffusion was the main mechanism of release, and
applying the Fick’s first law, the calculated indomethacin ester fluxes (J) decreased from
2.20 x 10-7 to 1.43 x 10-7 mg cm-2 min-1. So, the drug relative permeability decreased
according to the increase in the polymer concentration fitting a power law. Finally, after
increasing either the concentration of sorbitan monostearate or that of capric/caprylic
triglyceride, the core materials, the half-lives of the ester release varied from 198 to 365
and 266 to 495 min, respectively, keeping constant the polymer concentration. In
conclusion, the control of the indomethacin ester release is dependent on the
supramolecular structure of the carrier and it can be achieved either by changing the
thickness of the polymeric wall or by varying the concentration of the core constituents.
PREPARATION AND FUNCTIONALIZATION OF
POLY(BUTYLCYANAOACRYLATE) NANOPARTICLES AS DRUG
CARRIER SYSTEMS FOR THE BRAIN
Clemens K. Weiss1, Julia Schmitz-Wienke1,2, Volker Mailänder2, Thomas
Hauk3, Dietmar Fischer3, Katharina Landfester1; 1Dept. of Organic
Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm,
Germany, [email protected]; 2Department of Transfusion Medicine,
Institute for Clinical Transfusion Medicine and Immunogenetics,
Helmholtzstraße 10, 89081 Ulm, Germany; 3Institute of Experimental
Neurology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm,
Germany
397
Biodegradable poly(n-butylcyanoacrylate) (PBCA) nanoparticles are proposed for drug
delivery purposes to the brain. Although the mechanism and the requirements are not
completely elucidated, these particles are known to permeate the blood brain barrier
(BBB) and are thus able to deliver drugs into the brain. Polysorbate or poloxamer
211
functionalization of PBCA particles seems to enhance the permeating abilities.
Miniemulsion polymerization is a convenient way for the preparation of poly(nbutylcyanaoacrylate) nanoparticles and simultaneously control their surface properties.
First the monomer butylcyanoacrylate (BCA) is dispersed in an acidic, aqueous surfactant
solution to yield a stable miniemulsion. For the stabilization of the miniemulsion anionic
surfactants like sodium dodecylsulfate (SDS) could be used as well as nonionic
surfactants as polysorbates or poloxamer. In order to initiate the polymerization of BCA,
hydrophilic nucleophiles are added to the system. The choice of nucleophile determines
the functionalization of the particle surface. With this technique unfunctionalized, amino
acid functionalized and MethoxyPEG (MePEG)-functionalized particles could be
prepared. The particles can be labeled with a fluorescent dye or loaded with bioactive
substances as vitamins and drugs. Polysorbate or poloxamer functionalization can be
obtained by using either of these polymers as surfactant during the miniemulsion process.
Their nucleophilic hydroxy groups link the surfactant covalently to the particles. The
particle sizes can be adjusted between 60 and 250 nm with a narrow size distribution. ζpotential measurements indicate the presence of the desired functionality. Additionally
the molar mass of the PBCA was determined by GPC. The impact on biological systems
was assayed in various in vitro and in vivo studies. After incubation of several cell lines
(including mesenchymal stem cells and human microvascular endothelial cells) with
particle dispersions, the fluorescence intensity in the cells caused by the fluorescent dye
incorporated in the particles was determined by flow cytometry. Visualization of the cells
with the incorporated particles was performed with a confocal laser scanning microscope
(CLSM). The amount and kinetics of cellular uptake of the nanoparticles is determined
by the nature of the functional groups present on the particles and by the cell line. Brain
sections of rats, treated with various doses of particle dispersions showed a concentration
dependence of the BBB permeation of polysorbate functionalized PBCA-nanoparticles.
FABRICATION OF LIGAND-CONJUGATED MAGNETIC
NANOPARTICLES FROM MESOPOROUS SILICON FOR TARGETED
DRUG DELIVERY
Jarno Salonen1, A. Närvänen2 and V-P. Lehto1, 1Department of Physics,
University of Turku, FI-20014 Turku, Finland, 2Department of Biosciences,
University of Kuopio, FI-70211 Kuopio, Finland ; [email protected]
398
In the present work, magnetic mesoporous silicon nanoparticles have been fabricated for
targeted drug delivery applications. Silicon wafers have been electrochemically anodized
using a computer controlled pulsed etching current to vary the porosity of the structure
(pore diameter), and thus, the wall thickness between the pores. Periodically produced
thinner pore walls will function as predetermined sites for fracture in wet milling. Prior to
the milling, the porous layers were electrodeposited in aqueous FeCl3 solution in order to
make the structure magnetic. The wet milling was carried out in undecylenic acid
solution, which reacted with the new intact surfaces produced during the milling. The
covalently bound undecylenic acid enables the further functionalization of the particles
with standard biochemical procedures, e.g., to obtain ligand-conjugated magnetic
212
nanoparticles for targeted drug delivery. The nanoparticles have two functionalities: the
magnetic homing can be used to concentrate the nanoparticles close to the desired tissue
of organ and the ligand conjugation targets the particles to designed cell receptors. The
possible ligand conjugations and targeting studies will be discussed in the presentation in
detail.
DRUG LOADING TO LIPID-BASED COLLOIDAL CARRIERS
Heinrich Haas, Ursula Fattler, Medigene AG, D-82152 Martinsried,
Germany, Michael Wiggenhorn, Gerhard Winter, Ludwig Maximilian
University, Munich, Germany; [email protected]
399
Cationic colloidal carriers target proliferating (aniogenic) endothelial cells, which are
formed in pathological situations such as tumor growth and chronic inflammation. The
specific characteristics of angiogenic vasculature, inter alia the presence of excess
negative charge, are thought to be the foundation for binding. EndoTAG™ is a
technology platform of cationic lipid-based carriers for neovascular targeting. The first
product which has emerged from this new technology is EndoTAG™-1, a product
comprising cationic and zwitterionic lipids and the anti cancer agent paclitaxel. One
important issue in the development of such pharmaceutical formulations is to control
processes like drug loading to the carrier particle and drug release from the particle to the
aqueous environment. Here approaches to study and to improve drug loading to cationic
lipid carrier matrices are presented. Structural and functional coherencies at the molecular
scale are regarded. Particular attention is given to the role of electrostatic interactions for
the formation of drug-loaded colloidal carrier formulations.
NONLINEAR DIELECTRIC FUNCTION OF METAL NANOPARTICLES
AND OPTICAL SWITCHING
Yoshihiko Takeda, Hiroyoshi Momida, Masato Ohnuma, Takahisa Ohno and
Naoki Kishimoto, National Institute for Materials Science, Tsukuba, Ibaraki,
305-0003, JAPAN; [email protected]
400
Nanostructured metals are noteworthy optical materials because these notable optical
properties promise to be applied to biological plasmonic sensors and key components of
future optoelectronics devices. Optical nonlinearities are also applied to optical
switching of a single nanoparticle by optical bistability and so on. The optical
nonlinearities of metal nanoparticle materials are strongly reflected by a local electric
field and are enhanced in the vicinity of the surface plasmon resonance. For the design
of optical devices and the understanding of optical nonlinearities, it is significant to
evaluate the wavelength dispersion of nonlinear parts of the dielectric function of actual
materials. Here we present the dispersion of nonlinear dielectric function evaluated from
transient spectra of various metal nanoparticle materials. We discuss the contribution of
interband and intraband transitions and will mention the switching operation.
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POLYMER COLLOIDAL CRYSTALS FOR LASER APPLICATIONS
Seiichi Furumi, National Institute for Materials Science (NIMS), Tsukuba,
Ibaraki 305-0047, Japan; [email protected]
401
The monodispersed microparticles have an intrinsic capability to self-assemble the facecentered cubic lattice structures on the substrate from the suspension media. The highly
ordered 3-D architectures of colloidal particles are called as the colloidal crystals (CCs).
The CC structures have received tremendous interests as one of the alternative and facile
fabrication technique of the 3-D photonic crystal structures. Significant progress has
established not only various fabrication techniques for high-quality CCs, but also their
versatile applications to optical sensors with external stimuli. In this presentation, we
report a novel potential utility of CCs for the flexible polymer lasers by low-threshold
optical excitation. The laser cavity structure consists of an intermediate light-emitting
layer containing a fluorescent dye sandwiched between a pair of polymeric CC films.
The optical excitation of the device gave rise to the laser oscillation within the photonic
band-gap of the CC films. Interestingly, the laser action could be generated by optical
excitation even though the CC laser device of all polymer materials became bent shape
by mechanical stress.
COMPOSITE CONJUGATED POLYMER-FULLERENE
NANOPARTICLES AS MODEL SYSTEMS FOR THE STUDY OF
OPTOELECTRONIC PROCESSES IN ORGANIC PHOTOVOLTAIC
DEVICES
402
Andre J. Gesquiere, Daeri Tenery, Zhongjian Hu, NanoScience Technology
Center and Department of Chemistry, University of Central Florida, 12424
Research Parkway Suite 400, Orlando FL 32826, USA; [email protected]
Conjugated polymer based solar cells are a promising technology for effective solar
energy conversion. Unfortunately, the complexity of the morphological structure of the
organic materials at the molecular and mesoscale in these devices and the lack of
fundamental understanding of these materials and devices is significantly hampering
progress in the field. This is particularly the case for bulk-heterojunction organic
photovoltaic devices (BH-OPV), in which an interpenetrating network of electron donor
and acceptor materials provides a large interfacial area for efficient photoinduced charge
separation. However, one of the most severely limiting factors in these PV devices is the
resulting complex nanostructured morphology of the active layer that is created by
mixing of the electron donor and acceptor molecules. As a result, low carrier mobility
and inefficient carrier transport is typically observed. We have developed a novel
approach to spectroscopically investigate this issue in terms morphology and electronic
structure of the materials and their interfaces at the molecular scale. Novel composite
nanoparticles of the conjugated polymers MEH-PPV and P3HT doped with the fullerene
PCBM were fabricated and are observed to be excellent simplified model systems for the
study of molecular scale morphology effects at play in these complex nanostructured
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materials. Single particle spectroscopy reveals the extent to which variations in polymer
chain folding and interactions between polymer chains and fullerenes affect material
morphology, spectral- and optoelectronic properties, providing a detailed molecular scale
insight in the morphological effects at play in the active layers of bulk-heterojunction
organic photovoltaic devices that would otherwise be masked by the presence of the bulk.
SELF-ASSEMBLED QUANTUM DOTS WITHIN PHOTONIC CRYSTAL
NANOCAVITIES FOR THE REALIZATION QUANTUM NETWORKS
H. P. Seigneur, M. N. Leuenberger, and Winston V. Schoenfeld, CREOL:
College of Optics & Photonics, Univ. of Central Florida, Orlando, FL 32816;
[email protected]
403
Quantum dots offer many attractive features that are critical to quantum information
systems such as carrier localization and long decoherence times, making them an
excellent candidate for the realization of quantum bits (qubits). One often overlooked
element of quantum information is the quantum counterpart to information transfer
within a classical circuit. In quantum information one is subject to greater constraints
since quantum bits are represented as superpositions of states that are not simply
reproduced. In essence, reproduction or relocation of a quantum state requires quantum
teleportation, thus enabling quantum bit transfer within a quantum network. In this talk,
we will present the basis of a method to achieve quantum teleportation within quantum
networks through entanglement of a single photon polarization with a single excess
electron spin within a quantum dot. The discrete density of states of the quantum dot
provides a means to realize a two level system that can then be used to create
entanglement between a single photon and a single electron through the Single Photon
Faraday Effect. The basic physics behind the teleportation process will be presented
along with an outline of some of the existing hurdles that remain in moving towards the
physcial realization of such a teleportaion platform, most notably the design of a photonic
crystal host and the ability to controlably introduce a single quantum dot within a
designed nanocavity defect.
ELABORATION OF PHOTONIC COLLOIDAL CRYSTALS WITH A
WELL-DEFINED ARCHITECTURE
Pascal Massé, Jean-François Dechézelles, Renaud Vallée, Serge Ravaine,
CRPP – CNRS, Université Bordeaux-1, 115 avenue du Dr Schweitzer, 33600
Pessac, France; [email protected]
404
Colloidal crystals are expected to have applications in optical devices such as photonic
band gap crystals. For these applications, it is critical to fabricate a high-quality colloidal
crystal with a controllable organization. We present here the fabrication by the LangmuirBlodgett technique of three-dimensional colloidal crystals containing planar defects of
various types. We have investigated the structure-optical properties relationship of these
materials by combining Scanning Electron Microscopy (SEM) and Near-Infrared (NIR)
spectroscopy experiments. We show that the defect state position in the stop band varies
215
periodically with the value of the ratio of the diameter of the colloids of the lower and
upper opals to the size of the particles of the defect layer. Moreover, both the wavelength
and the magnitude of the pass band are found to continuously vary with the position (i.e.
altitude) of the defect layer inside the material. We demonstrate that the incorporation of
one to four periodically distributed planar defects in colloidal crystals induces the
opening of new gaps and bands in the original photonic band structure. These
experimental results were successfully simulated and the results of the simulations are
presented and discussed.
NANOSTRUCTURING SURFACES INTO 3D: INTEGRATING
LITHOGRAPHY AND SELF-ASSEMBLY
Jon A Preece, School of Chemistry, University of Birmingham, Edgbaston,
Birmingham, B15 2TT, UK, [email protected]
405
The creation of three-dimensional nanostructured materials is crucial to the development
of nanoelectronics, optical devices, drug delivery agent, biosensors and many other
nanometre-scale systems. However, the development of practical methods capable of
generating nanostructures and building up into the third dimension represents a major
task, and is one of the greatest technical challenges now facing nanofabrication. Perhaps
of the most interest for the future is the possibility of creating functional nanostructures
by combining bottom-up self-organisation of self-assembled nanoentities, which occur in
solution, with top-down lithographic approaches such as UV, X-ray and electron-beam
lithography. The integration of top-down approaches and bottom-up self-assembly
processes suggests that materials and subsequent devices could have multiple length
scales, from the micron to the atom. The term precision chemical engineering
encapsulates the precision engineering of writing to surfaces in a spatially controlled
fashion to direct the surface chemistry, coupled with the engineering that is involved in
fabricating three-dimensional architectures from the surface from molecular and
condensed phase entities. Another aspect that is encapsulated by this term is the fact that
the three-dimensional structures are not only engineered, but are held together by both
mechanical and chemical interactions. Thus, the stability of the three dimensional
structures will be dominated by thermodynamics as well as mechanics. This integration
of the two methodologies is representing a new paradigm for creating nanostructured
surfaces, and will involve close collaboration between scientists and engineers. This
lecture will report on progress in our laboratory on various novel self-assembled
materials coupled with various lithographic writing processes.
NEW TRACERS AND BIOLOGICAL SYSTEMS BASED ON
MULTIFUNCTIONNAL NANOSIZED HYBRID PARTICLES
Cédric Louis, Nicolas Charvet, Nano-H S.A.S., 23 rue royale, Lyon, 69001,
FRANCE; [email protected]; Stéphane Roux, LPCML, 22 avenue Gaston
Berger, Domaine scientifique de la Doua, 69622, Villeurbanne, FANCE,
Carole Farre, M. Lanselot, Carole Chaix, SMPH, UMR CNRS-bioMérieux
2714, 46, allée d'Italie, Lyon, FRANCE, Christophe Marquette, Loïc Blum,
406
216
Laboratoire de Génie Enzymatique et Biomoléculaire UMR CNRS 5013 Bat.
CPE – UCBL 43 Bd. du 11 Nov. 1918, 69622, Lyon, FRANCE
Assembled nanotechnology systems based on multifunctional nanoparticles open
prospects for promising applications or improvements of existing applications. The nano
size confers to the particles specific properties such as stealthiness and high colloidal
stability with respect to the environment. We describe our design, development, and
manufacture of nanopowders we designate as Nano-Hybrid Particles (NHP) and we
describe the biological surface modification of nanospheres for such NHP applications.
We describe the production and adaptation of hybrid nanoparticles where we combine in
a single small object, a multitude of organic dyes with luminescent and magnetic rareearth ions. This approach constitutes a promising strategy for achieving the preparation of
ultra-sensitive, multicolored and highly photostable luminescent tracers. Several
properties are concentrated inside these NHPs: magnetic (gadolinium oxide),
luminescent, surface fonctionnalisation, high stability, anti-bacterial effects. Inorganic
particles (3 to 100 nm) can be derivatized with organic compounds polysiloxane shell
layer, as is well known in the field. The flexibility and the large amount of available
functionality of organic compounds open new perspectives for inorganic nanometric
cores: better stability of the nanoparticles is assured, new physical and chemical
properties are obtained, and surface chemistry is suitably modified in order to optimise
tracer mobility and specificity. To functionalise nanoparticles different strategies are
used. One strategy is an indirect reversible grafting of nanoparticles to micron-sized
magnetic beads and the automated synthesis of probe (DNA) sequences directly at the
surface of the nanoparticles. The goal is to obtain luminescent biological probes. These
new materials are furtive, specific, adaptable and adjustable: chemically and physically.
These particles are therefore well-suited for tracking simultaneously several labeled
objects in various environments: in-vitro (IV injection), in-vivo (incubation) and in other
systems (liquid or solid). We integrate these new materials into several applications:
coding systems, authentification, biological detections, diagnostic systems, contrast
agents, therapeutic agents, and antibacterial agents, among others.
A CHEMICAL SYNTHETIC ROUTE TO COLLOIDAL MOLECULES
Adeline Perro,1,2 Etienne Duguet,2 Olivier Lambert,3 Jean-Christophe
Taveau,3 Elodie Bourgeat-Lami,4 Serge Ravaine1, 1CRPP – CNRS,
Université Bordeaux-1, 115 avenue du Dr Schweitzer, 33600 Pessac, France;
2
ICMCB – CNRS, Université Bordeaux-1, 87 avenue du Dr Schweitzer,
33608 Pessac Cedex, France; 3Molecular Imaging and Nano-Bio-Technology,
IECB, UMR-CNRS 5248, Université Bordeaux-1, 2 rue Robert Escarpit, F33607 Pessac, France; 4Chimie Catalyse Polymères Procédés – Equipe LCPP
- UMR 5265 CNRS/CPE/UCBL – ESCPE, Bâtiment 308 F, BP. 2077, 43
boulevard du 11 novembre 1918 - BP 2077, 69616 Villeurbanne Cedex,
407
217
One area of particular effort recently is the use of colloidal particles as precursors in
engineering new materials. Nevertheless, these particles are nearly always spheres. This
places limitations on the structures that can be built, especially in making photonicbandgap materials. Therefore, it is a great challenge to create new colloids with an
original shape, i.e. different from the sphere, in a controllable manner. We present here
an original approach to create organic-inorganic colloidal clusters with a perfect
controlled shape. The synthetic route of these structures, which are composed of spherical
silica spheres surrounded by a varying number of polystyrene nodules, consists in the
emulsion polymerization of styrene in presence of silica particles, which have been
surface-modified by a coupling agent containing polymerizable groups. We have
demonstrated that the colloidal clusters’ morphologies result from the minimization of an
energy term, which is the sum of an attraction towards the centre and two-body particle
repulsions which can balance the attractive central force. By varying the size of silica
seeds, the number of latex particles growing on their surface could be controlled and
predicted morphologies were observed, including line segments, triangles, tetrahedra, etc.
A main advantage of this technique is also that we can precisely control the reaction time,
allowing us to tune the final morphology of the colloidal clusters.
STRUCTURES OF GOLD NANOPARTICLES IMMOBILIZED ONTO
HYDROGEN-TERMINATED SILICON(111) SURFACE
Yoshinori Yamanoi, Kazuki Uchida, Tetsu Yonezawa, Nao Terasaki, and
Hiroshi Nishihara Department of Chemistry, School of Science, The
University of Tokyo, Hongo 7-3-1,Bunkyo-Ku, Tokyo, Japan;
[email protected]
408
Silicon is the most important material in modern technology by virtue of three useful
characteristics: (1) easily available substrate, (2) easy preparation of highly purified
crystals, and (3) precise control of electrical conductivity by doping. Recently, the
organic modification of silicon surfaces has attracted much interest in both surface
science and organic chemistry. A useful approach is the covalent attachment of
unsaturated hydrocarbons with atomically flat hydrogen-terminated silicon (H-Si)
surfaces through the hydrosilylation reaction. A variety of organic monolayers have been
demonstrated to attach covalently to silicon surfaces through stable silicon-carbon bonds
(340 kJ/mol). Nanoparticles exhibit a range of physical and chemical properties that are
promising for potential applications in new generations of electronic, optical, and
chemical devices. Immobilization of nanoparticles in a single layer on conductive or
semi-conductive surfaces is required for application to nanosized devices. For example,
single electron tunneling of a gold nanoparticle on a gold surface through , -dithiol
was reported, although the gold nanoparticles were found to move on the gold surfaces
due to weak Au-S bonding (167 kJ/mol) under ambient conditions. We report here the
immobilization of -alkene-1-thiol-protected gold nanoparticles and 4ethynylbenzenethiol-protected gold nanoparticles on a hydrogen-terminated silicon(111)
surfaces by thermal treatment through alkyl chains and -conjugated chains,
218
respectively. The detailed structural examinations of the modified silicon surfaces were
investigated by HR-SEM, AFM, and cross-sectional TEM. This method enabled the
immobilization of a gold nanoparticle at a specific site on a silicon surface by a strong
covalent bond.
LANGMUIR ADSORPTION STUDY OF CdSe/ZnS QUANTUM DOTS ON
SYNTHETIC TEMPLATES: INFLUENCE OF SUBSTRATE SURFACE
CHEMISTRY AND pH
Jungjin Park, Silvia H. De Paoli Lacerda, Scott K. Stanley, Brandon Vogel,
Jack F. Douglas, Dharmaraj Raghavan* and Alamgir Karim; Polymers
Division, National Institute of Standards and Technology, Gaithersburg,
Maryland 20899, USA; [email protected]; *Department of Chemistry,
Howard University, Washington, DC 20059
409
We consider the utility of Langmuir adsorption measurements for characterizing
nanoparticle-substrate interactions. Spherical CdSe/ZnS core-shell quantum dot
nanoparticles (QD) were chosen as representative particles because of their widespread
use as fluorescent biological labels, facile control over ligand chemical functionality, and
their relatively monodisperse size. Model self-assembled monolayer (SAM) substrates
were similarly utilized because they allowed for precise control of substate chemistry.
In our initial exploratory measurements, we kept the QD functional group invariant and
varied the chemistry of the substrate through the choice of the SAM molecule end-group
moeity. Specifically, the QD were functionalized with 11-mercaptoundecanoic acid and
self-assembled monolayer (SAM) substrate containing amine (–NH2) was prepared and
the SAM substrates employed (–CH3) and(–COOH) end-groups. First, we followed the
kinetics of nanoparticles adsorption on the aminosilane SAM layer by quartz crystal
microgravimetry (QCM) over a range of particle concentrations, and then we deduced the
corresponding Langmuir adsorption isotherms desribing the concentration adsorbed at
equilibrium as a function of temperature. Analysis of this data allowed us to determine
the Langmuir adsorption equilibrium constant (KL ≈ 2.25 μM-1 ), quantifying the particlesubstrate interaction, and the maximum particle coverage (θmax ≈ 224 ng/cm2) under the
thermodynamic conditions investigated (25 °C, pH = 9). We then explored the effect of
varying pH on Langmuir adsorption to gain insight into the role of electrostatic
interactions on nanoparticle adsorption. Our study shows that more nanoparticles were
adsorbed on the aminosilane surface under neutral pH conditions than either acidic or
basic pH solutions. This change in nanoparticle adsorption with pH was further
quantified and confirmed by X-ray photoelectron spectroscopy (XPS) and confocal
fluorescence microscopy measurements. We conclude from this exploratory study that
Langmuir adsorption measurements provide a promising approach to quantifying
nanoparticle-substrate interactions. This metrology should be useful for better
understanding and controlling synthetic nanoparticle self-assembly processes at interfaces
and interactions between nanoparticles and biological materials.
219
COATING AND FUNCTIONALIZATION OF PARTICLES USING
INITIATED CHEMICAL VAPOR DEPOSITION (iCVD)
Kenneth K. S. Lau, Department of Chemical and Biological Engineering,
Drexel University, Philadelphia, PA 19104, USA; [email protected]
410
Initiated chemical vapor deposition (iCVD) represents a novel CVD method for
producing thin polymer coatings. iCVD utilizes benign and selective chemical pathways
via polymerization mechanisms typical of liquid-based chemistries to produce linear
stoichiometric polymers with full retention of monomer functionality. By combining the
strengths of tunable materials design found in liquid synthesis and precision nanoscale
control found in a solvent-free CVD environment, we will demonstrate iCVD’s ability to
functionalize and encapsulate particles down to the nanoscale. We will present examples
of coating particles using iCVD to create superhydrophobic surfaces; to produce reactive
surfaces for binding; to give core-shell refractive index contrast; and to apply coatings for
controlled drug release. Results from FTIR, XPS, SEM, TEM, AFM, VASE, UV-vis and
GPC will be used to show the nature, including composition, structure and properties, of
these iCVD films. A discussion will also be made on our experimental and modeling
work in understanding iCVD polymerization kinetics.
SURFACE FUNCTIONALIZATION OF NANOPARTICLES FOR CELLTARGETED DRUG DELIVERY
F. Cengelli1, J. Grzyb2, F. Tschudi-Monnet3, X. Montet4, A. Montoro1, H.
Hofmann5, S. Hanessian2, L. Juillerat-Jeanneret1; 1University Institute of
Pathology, University of Lausanne, Lausanne, Switzerland; 2Department of
Chemistry, University of Montreal, Montreal, Canada; 3Institute of
Physiology, University of Lausanne, Lausanne, Switzerland; 4Department of
Cell Physiology and Metabolism and Medical Radiology, University of
Geneva, Geneva, Switzerland; 5EPF Lausanne, Lausanne, Switzerland;
[email protected].
411
SuperParamagnetic Iron Oxide Nanoparticles (SPIONs) with a core size of 9-10 nm
diameter and polymer coatings such as polyvinyl alcohols (PVA) may be useful both for
selective disease detection by MRI and targeted drug delivery provided that their polymer
surface is functionalized with therapeutic drugs and/or cell-targeting molecules. Our
objectives are to develop surface-functionalized-SPIONs and to evaluate their
biocompatibility, uptake by specific cells and cellular localization in cells and organs, and
their therapeutic efficacy. Using 2-dimensional cell cultures the presence of amino groups
on the SPIONs coating was shown to be mandatory for cell uptake, and this uptake did
not modify cell proliferation. The fluorophore-modified polymer coatings and the iron
oxide core of SPIONs were vizualized by confocal microscopy and by prussian blue
detection and electron microscopy, respectively, demonstrating cell internalization. In 3dimensional cell culture models SPIONs were found associated with cells, being able to
invade tumor spheroids but not differentiated brain aggregates. In vivo aminofunctionalized-SPIONs were found in the spleen and the liver but not the brain and
220
kidneys. SPIONs functionalized via specific aminoPVA-linkers by the therapeutic drugs
doxorubicin, 5-fluorouridine or campthotecin displayed anti-tumor activity, but this effect
was dependent on the chemical characteristics of the drug-linkers and the intracellular
localization of the drug-SPIONs. SPIONs uptake by cells and anti-tumor efficacy of
drug-functionalized-SPIONs were increased in the presence of an external magnetic field.
These approaches gave a proof of concept of the feasibility of using drug-functionalizedSPIONs in biological systems for magnetically targeted delivery of therapeutic agents to
human cells and of their potential to be selectively taken up by living cells in 3dimensional structures.
BLOCK COPOLYMERS FOR THE STABILIZATION OF GOLD
NANOPARTICLES IN WATER
Kamil Rahme, Fabienne Gauffre, Jean-Daniel Marty and Christophe
Mingotaud, IMRCP Laboratory, Paul Sabatier University, CNRS UMR 5623,
31062 Toulouse cedex 9, France. [email protected]
412
We develop new strategies to stabilize nanoparticles in water, avoiding formation of
covalent interactions between the stabilizer and the surface of nanoparticles that might
inhibit their properties. For this aim we used neutral diblock and triblock copolymers that
are amphiphilic and capable to self-organize around the nanoparticles. EOx-POy-EOx
(Pluronics®) had been efficiently used in the molecular state (unimers), for the
stabilization of gold nanoparticles (AuNps) in NaCl aqueous solutions. These polymers
were compared in the same conditions with other PEO based polymers such as EOx
homopolymer and EOx-POy diblock copolymers. The effects of concentration and
structure of the block copolymer (including block lengths, and overall length of the
polymer) have been systematically investigated, using well-defined AuNps (diameter ~12
nm). Aggregation and precipitation processes were assessed separately using empirical
parameters calculated from optical absorbance spectra. Different aggregation states were
observed and characterized by the displacement of the plasmon resonance band of the
AuNPs. Increasing the concentration, PEO and PPO block lengths, or the overall length
of the polymer enhanced the colloidal stability of nanoparticles. Among all these
parameters the length of the PPO block shows the most important influence on the
stability. Different techniques such as Dynamic Light Scattering, TEM, cryoTEM and
Small Angle Neutron Scattering with contrast variation have been used to study the
structure of Polymer-AuNPs aggregates. It was observed that in the presence of AuNps,
under conditions where micelles are not formed (T < CMT), polymer adsorbs over the
AuNps forming large globules, that may explain the achieved colloidal stability. A study
of the cytotoxicity of the system Polymer-AuNPs was accomplished on fibroblast cells.
Results show low or no cytotoxicity. In conclusion this strategy using non-toxic
PEO/PPO block copolymers can be applied to efficient stabilization of AuNPs in water,
and present great potential for biological applications.
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BRIDGING THE GAP: FROM CONDUCTING POLYMER NANOWIRES
TO MOLECULAR AND SINGLE ATOM DEVICES
Neil T. Kemp,1,2 Jack W. Cochrane2 and Richard Newbury2; 1. Institut de
Physique et de Chimie des Matériaux de Strasbourg, France; 2. School of
Physics, University of New South Wales, Sydney, Australia;
[email protected]
413
One-dimensional nanostructures such as nanowires and nanotubes have received much
attention due to their unique physical and electrical properties, and their prospects for
application in devices such as ultra-sensitive chemical and biological sensors, transistors,
logic gates and miniaturized electronic circuits. Although conducting polymer nanowires
and nanotubes have been fabricated for more than ten years, integration into devices in a
cost-effective manner for large-scale production remains a challenge. In this report we
demonstrate a template-free electrochemical method for growing ordered conducting
polymer nanowires within pre-fabricated devices such that electrical contacts are made in
situ during the polymer synthesis, thereby avoiding the difficulties associated with
positioning the nanowires and making electrical contacts post-synthesis. The devices we
have made show excellent electrical connections and the controllable geometry of the
nanowire growth is shown by the progressive transition in dimensionality of devices
consisting of 1) planar 3-D ordered nanowire arrays bridging 500 nm junctions to 2) a
linear 2-D ordered nanowire array, and ultimately, 3) a single 1-D ordered nanowire
bridge. We report on the electrical transport properties of the nanowires, which show
evidence for Coulomb Blockade transport at low temperatures, and demonstrate the use
of the nanowires as highly sensitive chemical sensors. The development of a “Lab on a
Chip” style fabrication platform for making “bridged” molecular and single atom
electronic devices via electrochemical techniques will additionally be presented. The
approach, which integrates microfluidics with a silicon chip containing lithographically
defined circuits, allows for the formation of sub nanometer spaced electrodes and the
easy insertion of molecular entities. Using this technique single atom junctions displaying
quantized conductance have been fabricated.
ELECTRON INDUCED FIELD-EMISSION FROM CARBON
NANOTUBES
Alireza Nojeh, Department of Electrical and Computer Engineering,
University of British Columbia, Vancouver, BC V6T 1Z4, CANADA;
[email protected]
414
Carbon nanotubes, hollow cylindrical structures of carbon with nanometer scale
diameters, have been one of the centers of attention in the world of nanotechnology for
over 15 years due to their outstanding properties such as mechanical and electronic
characteristics. One particularly promising area of application of carbon nanotubes is
electron emission. Electron sources are in demand in many applications including
electron-beam lithography and microscopy, synchrotrons, electron holography, flat-panel
displays, and free-electron analog to digital conversion. More recently, the emerging area
of vacuum nanoelectronics with promise for high-frequency applications is creating a
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new demand for nanoscale, well-controlled electron sources. Typically, electrons can be
emitted from a material using thermionic emission, field-emission (by quantummechanical tunneling), Schottky emission (using a combination of heat and field) and
photo-emission. Nanotubes are particularly good candidates for field-emission due to
their high aspect ratio, leading to strong enhancement of an externally applied field and
therefore emission at low applied voltage. This is particularly appealing for applications
such as field-emission displays. Moreover, due to their small emission spot and high
current-carrying capability, nanotube electron emitters have already demonstrated
brightness levels of an order of magnitude better than traditional field-emitters. In this
talk, a new mechanism of electron emission from single-walled carbon nanotubes will be
discussed. In the described experiment, the nanotube is under an external field just below
the threshold of field-emission. Under this condition, electrons from the nanotube shank
accumulate at the tip, but do not have enough energy to overcome the emission barrier. A
“primary” electron beam then hits the nanotube tip and provides the necessary “kick” to
the nanotube electrons and make them emit. For every primary electron hitting the
nanotube tip, a large number of electrons are emitted from the nanotube – multiplication
factors (ratio of emitted to incident electrons) of up to 100 were measured. This strong
amplification (compared to the normal secondary electron emission coefficient of
materials typically around 1 to 2) provides opportunities for new high-gain electron
multipliers, ultra-high-spatial-resolution electron detectors and nanoscale vacuum
transistors. A model based on first-principles calculations to explain the phenomenon will
also be presented.
UTILIZING THE LABILITY OF LEAD CHALCOGENIDES TO
PRODUCE HETEROSTRUCTURED NANOCRYSTALS WITH BRIGHT,
STABLE INFRARED EMISSION
Jeffrey M. Pietryga and Jennifer A. Hollingsworth, Chemistry Division, Los
Alamos National Laboratory, Los Alamos, NM 87545, USA;
[email protected]
415
Lead chalcogenide nanocrystal quantum dots (NQDs), and PbSe NQDs in particular,
provide efficient emission over a large spectral range in the infrared, but their application
has been limited by instability in emission quantum yield and peak position on exposure
to ambient conditions. Conventional methods for improving NQD stability by applying a
shell of a more stable, wider-bandgap semiconductor material are frustrated by the
tendency of lead chalcogenide NQDs towards Ostwald ripening at even moderate
reaction temperatures. Here, we describe a partial cation exchange method by which we
take advantage of this lability to controllably synthesize PbSe/CdSe and PbS/CdS
core/shell NQDs. These new heterostructured NQDs show improved emission efficiency
and, critically, are stable against fading and spectral shifting for at least several months.
Further, these NQDs are also stable enough at elevated temperatures to undergo
additional shell growth to produce PbSe/CdSe/ZnS core/shell/shell NQDs that represent
initial steps toward bright, bio-compatible optical labels emitting at tissue-transparent
wavelengths.
223
SYNTHESIS AND CHARACTERIZATION OF CARBON NANOTUBE
ENCAPSULATED FERROMAGNETIC METAL NANOWIRES:
TOWARDS SPIN ELECTRONIC APPLICATION
Yasuhiko Hayashi1 and Gehan A. J. Amaratunga2; 1Department of Frontier
Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya,
466-8555 Japan; 2Centre for Advanced Photonics and Electronics,
Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue
Cambridge CB3 0FA, United Kingdom; [email protected]
416
Encapsulating carbon nanotubes (CNTs) with various materials, such as metals and their
compounds or organic molecules, is highly attractive for the development of carbonbased nanomaterials with new electronic, magnetic properties. Especially, aligned metal
encapsulated CNTs or nanowire inside CNTs with ferromagnetic metals such as Fe, Ni,
Co or their compounds have significant potential in high density magnetic recording
media due to their nanoscale size and strong anisotropic property, leading to small bit
size. Moreover, the tube structure provides an effective barrier against oxidation effect,
which significantly influences the magnetization in ferromagnet inside tube. Here we
present a growth and characterization of self-assembled aligned PdxCo1-x alloy nanowire
encapsulated MWCNT arrays on Pd/Co thin layers coated Si substrate (Pd/Co/Si) by dc
bias-enhanced plasma CVD (dc BE-PCVD) method with C2H2 and NH3 as the reaction
gasses. We also prepared MWCNTs grown on a Co thin layers coated Si substrate
(Co/Si) to know the effect of a Pd layer on the top of a Co layer. Pd/Co multi-layers itself
have attracted much interest for future magnetic recording media, due to their strong
perpendicular anisotropy induced by a PdxCo1-x alloy. The magnetic properties of large
area PdxCo1-x alloy nanowire encapsulated inside MWCNTs were investigated by a
vibrating sample magnetometry (VSM). Off-axis electron holography in the transmission
electron microscope (TEM) was used to correlate the magnetic microstructure of
magnetite PdxCo1-x alloy nanowire in individual MWCNTs. The SEM images show the
teardrop-shape particles encapsulated in the tube top of MWCNTs. The alignment and
density of MWCNTs on the Pd/Co/Si substrate are better and denser than that of
MWCNTs on Co/Si substrate. The energy dispersive X-ray spectroscopy (EDS)
measurements for the encapsulated metal inside MWCNTs showed that the metal seems
to be chemically uniform and to be PdxCo1-x alloy and the atomic ratio of Pd:Co is
approximately 1:1 from the semi-quantitative of the EDS spectrum. The hysteresis loop
of the ferromagnetic metal nanowire encapsulated inside MWCNTs shows clear
ferromagnetic behavior and the easy axis of magnetization is parallelly (PL) to the
MWCNT tube axis, as can be elucidated from the large coercive fields (Hc) and
remanence (Mr) values. The phase shift caused by the magnetic flux is clearly observed
outside the tube indicating a magnetization parallel to the tube axis by electron
holography. And the magnetic field lines show a magnetic symmetry of the metal
nanowire encapsulated inside MWCNTs. The powerful technique of the electron
holography in the TEM enabled us to obtain the saturation magnetization of “each” and
the magnetic “interaction” between PdxCo1-x alloy nanowire encapsulated inside
MWCNTs by calculating the magnetic field lines. Our results demonstrate significant
progress towards the goal of producing spinelectronic devices from ferromagnetic
224
PdxCo1-x alloy nanowire encapsulated inside MWCNTs.
Session E4– Contributed Paper
SILVER NANOWIRES - A LOW VOLUME ADDITIVE FOR HIGH
THERMAL AND ELECTRICAL CONDUCTIVITY
Richard Baldwin, nanoComposix, 4878 Ronson Court, Suite K, San Diego,
CA 92111, USA, [email protected]
417
For many materials it is desireable to have high thermal or electrical conductivity. One
possible route to such properties is the addition of thermally and electrically conductive
nanoparticles. However, high loadings of such materials may have deleterious effects on
other properties, such as a loss of mechanical strength in solids, or high viscosity in
liquids. Additives with high aspect ratios allow for a greater increase in conductivity for a
given mass or volume loading. Silver nanowires with lengths in the tens of microns and
widths in the tens of nanometer range allow for the generation of a thermal or electrical
percolation network at very low loadings. We report here the preparation and
charaterization of these silver nanowire composites, in the form of electrically conductive
polymers (resistivity less than 0.001 Ωcm for a volume loading of 6% in polyurethane)
and as thermal management fluids ( 0.5 wt % silver nanowires increasing the thermal
conductivity of water by 68%).
LARGE SCALE FABRICATION APPROACH OF CARBON NANOTUBE
BASED ELECTRONIC DEVICES
Saiful I. Khondaker and Paul Stokes, Nanoscience Technology Center and
Department of Physics, Uinversity of Central Florida, Orlando, FL 32826,
418
Carbon nanotube (CNT) is considered to be an ideal candidate for the fabrication of
nanoscale electronic devices such as field effect transistors (FETs) and single electron
transistors (SETs) owing to its nanometer-sized diameter and exceptional electrical
properties. Early fabrication techniques of CNT devices involved random placements of
CNT, locating them with atomic force microscopy (AFM), and finally defining source
and drain electrodes using electron beam lithography (EBL). In addition, most of these
devices were often controlled by a global back gate because of its ease of processing.
Such fabrication processes neither offer high throughput nor individual control of each
CNT device necessary for parallel fabrication of nanoelectronic devices. In this talk I will
present our current efforts for large scale fabrication of locally controllable CNT-FET
and CNT-SET devices. The approach is based on directed assembly of individual single
walled carbon nanotube from dichloroethane via AC dielectrophoresis (DEP) onto prepatterned source and drain electrodes with a local aluminum gate in the middle. We find
that both metallic and semi-conducting nanotubes can be assembled. For semiconducting nanotubes, we show that the measured device performance such as
subthreshold swing of local-gated semiconducting nanotube FET is superior compared to
the global back gated device possibly due to channel controlled operation. At low
225
temperature, we find that both metallic and semiconducting nanotubes show SET
behavior and the SET size is defined by the size of the aluminum gate. Directed assembly
of local gated CNT devices at selected position of the circuit via DEP pave the way for
large scale fabrication of CMOS compatible nanoelectronic devices.
RAMAN SPECTROSCOPY OF CARBON NANTUBES AND
NANOWIRES PREPARED BY ARC DISCHARGE IN LIQUID
NITROGEN
Giuseppe Compagnini, Luisa D’Urso, Paola Russo, Dipartimento di
Chimica Università di Catania, Viale A. Doria 6 Catania 95125 (Italy); Silvia
Scalese, Viviana Scuderi, Vittorio Privitera CNR-IMM Stradale Primosole 50
Catania 95100 (Italy); [email protected]
419
In the last few years plasma processes confined in liquid media have been increasingly
considered for the possibility to obtain nanostructures for several materials. Laser
ablation as well as the ignition of arc discharges in different environments have been
studied for the formation of metal nanoparticles as well as carbon based nano-materials.
In this work we present some results obtained by the ignition of arch discharges in liquid
nitrogen using graphite electrodes. We discuss about the deposition of Multi-Wall Carbon
Nanotubes (MWCNTs) and the encapsulation of linear carbon chains to form hybrid
CnH2@CNT structures at the cathode, with features depending on the discharge
conditions. Raman spectra and Transmission Electron Microscopy will be used to
characterize the obtained samples. In particular the analysis of the first and second order
Raman signals gives a general trend in which CNTs’ ordering increases by increasing the
discharge current form 10 to 100 A. Moreover a strong correlation between the orderdisorder properties of the CNTs and the presence of linear carbon chains embedded has
been observed. The origin of the carbon nanowires’ spectral features and their correlation
with disorder are discussed in the frame of some theoretical considerations given in
literature.
COOPERATIVE ASSEMBLY ROUTES FOR NANOCOMPOSITES
Muhammet S. Toprak, Functional Materials Division, Royal Institute of
Technology, 16440 Kista, Stockholm, Sweden; [email protected]
420
The ability to assemble materials that are organized over different length scales has a
recognized importance for the development of new functional materials. In particular,
the potential for application of emerging nanoscale objects can often only be realized by
arranging such components into larger scale assemblies. Complex coacervation is one
phenomenon that presents new opportunities for single-step syntheses of ordered micronscale objects that are composed from predefined nanoscale objects. Coacervation is a
spontaneous aqueous phase separation that often produces microspheres from oppositelycharged chemical entities. We have previously studied such assemblies made from
organic ions, metallic nanoparticles, or quantum dots, and have utilized the coacervates’
226
chemical properties to form inorganic shell structures. We have sought to extend the
variability of assembly components, to in turn extend the variety of potential uses. This
work demonstrates use of coacervation that uses magnetic nanoparticles as assembling
components. Various functional nanoparticles including metallic and semiconducting
(quantum dots) are also introduced into the assembly. The resulting objects retain the
original magnetic properties, and are unusually robust under various conditions. We also
demonstrate the potential use of these hybrid assemblies for biomedical applications.
SOLID PARTICLES IN LIQUID FILMS
Tommy S. Horozov, Surfactant & Colloid Group, Department of Chemistry,
University of Hull, Hull, HU6 7RX, U. K.; [email protected]
421
Solid colloidal particles can spontaneously attach to air-water or oil-water interfaces and
act as an effective stabiliser of foams and emulsions even in the absence of any
surfactant. The thinning and stability of the liquid films separating the bubbles or droplets
are crucial for the overall stability of foams and emulsions. They are strongly affected by
the presence of particles in the films. To understand better the role of solid particles in
such systems we investigate the behaviour of micrometer and submicrometer solid
particles in free standing liquid films. The films are observed in monochromatic reflected
light and the thickness profile of the film meniscus is reconstructed from the interference
pattern. It is used to determine the three-phase particle contact angle at the liquid
interface in real time without the need of sophisticated equipment or complex
calculations. The Brownian motion of an ensemble of particles simultaneously attached
to both film surfaces is analysed and information about their lateral interactions is
obtained.
TAILORING THE PHYSICAL PROPERTIES OF GOLD
NANOPARTICLE/POLYMER COMPOSITES
M. A. Garcia1, V. Bouzas1,M. Bernabo2 D. Haskel3, A. Pucci2, G. Ruggeri2,
J. de la Venta1, E. Fernández-Pinel1, J. Lal4, M. Bleuel4, S. G. E. te Velthuis5,
A.Hoffman5,6, J. Llopis1, C. deJulian7; [email protected]. 1Dpt. of
Materials Physics, Universidad Complutense de Madrid, Spain 3Dpt. of
Chemistry and Industrial Chemistry, Università Degli Studi di Pisa, Pisa,
ItalY 3Advanced Photon Source, Argonne National Laboratory, Argonne, IL,
USA 4; Argonne National Laboratory Argonne, IL, USA 5 Materials Science
Division, Argonne National Laboratory, Argonne, IL USA 6Center for
Nanoscale Materials, Argonne National Laboratory, Argonne, IL USA
7
Molecular Magentism Laboratory, University of Firenze, Italy
422
Nanoparticles (NPs) are interesting systems since they present different properties than
bulk materials with the same composition. NPs exhibit a large fraction of surface atoms,
which are different to those of volume mainly due to the broken symmetry at the surface
which alter their electronic configuration and consequently their physical and chemical
properties depending on electronic states. Moreover, the features of these surface atoms
227
can be altered by bonding with other species, as organic molecules, arising new physical
properties. A surprising example of these surface effects is the observation of magnetism
at room temperature in gold NPs capped with dodecanethiol in spite of the diamagnetic
behaviour of the bulk gold. This magnetism is related to the polarization of the bonds
between the Au surface atoms and the sulphur atoms at the end of thiol chains. Capping
the nanoparticles with thiols also varies its optical properties, modifying the absorption of
surface plasmon resonances. A more interesting observed effect when a chorophore is
attached to the particle through the thiol change. We recently demonstrated that in this
system, the polarization of light is preserved during energy transfer between the
chromophore and the NP, an effect never observed before. These outstanding properties
are retained when the particles are embedded in a polymeric matrix that provides a
substrate for an easy handling of the NP. This polymer containing the thiol capped Au
NPs can be stretched before it becomes stiff. We have confirmed by EXAFS
measurements that this stretching process alters the features of the Au-thiol bonds,
inducing anisotropies in the optical and magnetic properties of the material. This is a new
method to induce anisotropy that can be used to provide metal nanoparticles able to
recognize anisotropic environment and for the design on novel linear polarizers.
Furthermore, it represent a new method to tune the physical properties of hybrid
nanostroctures consisting on hard/soft matter that can be applied to many other materials
than thiol capped Au NPs.
GRAFTING OLIGOMERIC IONMERS TO SILICA NANOPARTICLES
VIA ATRP APPROCH AND THEIR APPLICATION IN PEM FUEL CELL
Xinhui Zhang†, Zhaolin Liu†, Liang Hong*† Siok Wei Tay†: †Institute of
Materials Research & Engineering, * Department of Chemical &
Biomolecular Molecular Engineering, National University of Singapore;
[email protected]
423
This work reports an innovative method to restructure the Nafion® membrane via
dispersing into the matrix of it a low content of chemically modified silica nanoparticles,
which have a thin layer of the grafted ionmer chains, known as the “hairy” layer. Anionic
type polyelectrolyte chains were grafted to silica nanoparticles via surface-initiated atom
transfer radical polymerization (ATRP). This grafting polymerization results in a soft and
thick polymer layer surrounding the silica core according to TEM and DSC observation.
Two types of vinyl monomers, i.e. 3-sulfopropyl acrylate, potassium (SAP) and 3imidazoly-2-hydroxyl-propyl methacrylate (IPMA) were employed to construct the soft
layer, which can be either homopolymeric or copolymeric structure. The resulting
nanocomposite membranes revealed clearly better fuel cell performance as well as lower
methanol permeability in contrast to the pristine Nafion membrane.
228
SYNTHESIS AND APPLICATIONS OF CLASSES OF NONCARBONACEOUS NANOSTRUCTURES
Stanislaus S. Wong, Brookhaven National Laboratory, Stony Brook, SUNY,
79 Cornell Avenue, Upton, NY 11973, USA; [email protected]
424
Environmentally friendly synthetic methodologies have gradually been implemented as
viable techniques in the synthesis of a range of nanostructures. In this work, we focus on
the application of green chemistry principles to the synthesis of complex metal oxide and
fluoride nanostructures. In particular, we describe advances in the use of templatedirected techniques as environmentally sound, socially responsible, and cost-effective
methodologies that allow us to generate nanomaterials without the need to sacrifice on
sample quality, purity, crystallinity, in addition to control over size and shape.
FUNCTIONAL PAPER BASED ON PHOTOLUMINESCENT
NANOPARTICLES ADSORPTION ON MODIFIED CELLULOSE FIBRES
Pierre Sarrazin, Didier Chaussy and Davide Beneventi, Laboratoire de génie
des procédés papetiers, 461 rue de la Papeterie BP65 - 38402 Saint Martin
d'Hères, France ; [email protected]; Laetitia Vurth and Olivier
Stephan, Laboratoire de spectroscopie Physique, 140 avenue de la Physique
BP87 - 38402 Saint Martin d’Heres, France
425
The elaboration of paper sheets bearing new functional properties is becoming a
promising way to broaden the use of cellulose-based materials to application fields
currently restricted to synthetic polymers. Nowadays, the two main techniques used to
manufacture functional paper sheets are coating or printing active slurries on a preformed
fibre network. In these cases, specific properties arising from these treatments are mostly
developed at the surface of the paper. Nevertheless the bulky functionalization of a paper
sheet is also possible by a modification of individual fibres in aqueous suspension before
the formation of the paper sheet. The objective of this study was to elaborate a bulky
photoluminescent paper using copolyfluorene as active polymer. Photoluminescent
and/or conducting organics polymers are currently emerging as outstanding candidates
for the manufacturing of new composite materials for low-cost electronic devices. Main
advantages of these tailored compounds are the cost and the easiness of conception.
Besides the classical vacuum evaporation coating, conducting or photoluminescent
polymers can be dissolved in organic/aqueous mixtures and miniemulsified in water to
give stable emulsions with controlled droplets size. Towards thy meaning, an active
photoluminescent copolyfluorene was synthesised in both steps to obtain an amorphous
orange solid. The copolymer was efficiently emulsified with a cationic surfactant to reach
stable yellowish photoluminescent nanosized positive charged particles. Copolyfluorene
colloids were adsorbed on cellulose fibres which are originally charged negatively by the
presence of carboxylic functions. The adsorption was carried out with a low and
sufficient amount of colloids to create bulky efficient photoluminescent handmade paper
sheets. In order to improve the adsorption of copolyfluorene colloids, a chemical and a
229
mechanical treatment were carried out on cellulose fibres. Namely, TEMPO oxidation
and beating. The selective TEMPO mediated oxidation of secondary alcohol groups of
cellulose fibres into carboxylic functions led to an increase of negative charges and
consequently in an improvement of the fibre adsorption capacity and sheet
photoluminescence. Beating is an intense mechanical treatment which increases
cellulose fibres accessibility by shortening and peeling fibres. Beating yields fines, very
short fibres, which can adsorb more colloids because of their higher specific surface area.
The high adsorption capacity of beaten fibres is counterbalanced by fines loss during the
sheet formation process. Under the tested conditions beating led to a decrease in sheet
photoluminescence. Micrographs under UV-light showed the presence of
photoluminescent spots on the fibre surface indicating that copolyfluorene colloids were
adsorbed as large aggregates. An homogenous fibre coating was reached by stabilizing
the colloidal suspension during the adsorption step by adding a cationic surfactant which
prevented colloids aggregation. However, the presence of a continuous coating layer
decreased hydrogen interactions between fibres and thus slightly decreased paper sheets
strength.
230
Abstracts of Poster Program
Poster Session P1
PALLADIUM-COBALT NANOPARTICLES ON CARBON SURFACES:
AN ELECTROCHEMICAL AND SURFACE ANALYSIS
Lisandra Arroyo-Ramírez, Raphael G. Raptis and Carlos R. Cabrera,
Department of Chemistry and Center for Nanoscale Materials, University of
Puerto Rico-Río Piedras, PO Box 23346, San Juan, PR 00931-3346;
[email protected]
109
Nano-sized metal particles continue to attract interest for different researcher areas due to
their different physical and chemical properties when compared to bulk material. The
common catalysts are easily poisoned and expensive; therefore research has been going
into maximizing the catalytic properties of other metals by shrinking them to
nanoparticles in the hope that will be an efficient and economic alternative. Metal
nanoparticles can be prepared by chemical methods allowing the control of size and
composition distribution of the particles. In these methods precursors are usually used as
starting material. Additionally, the demand for tailored catalytic nanoparticles has
encouraged the use of heterobimetallic molecular precursors. Our focus is on the catalyst
synthesis by single source precursor with metal(1)-metal(2) ratio predetermined in the
complex. In this work, we describe the study of deposition and reductive decomposition
of the heterobimetallic precursor [NH4]2CoPd2(Me2Ipz)4Cl4 (CoPd2) on carbon surfaces
such as: highly ordered pyrolytic graphite (HOPG) and carbon black (Vulcan). This type
of organometallic compound will be used as precursor for the preparation of an oxygen
reduction reaction catalyst. The nanopartricles formation was characterized by cyclic
voltammetry (CV) and surface analysis techniques, such as: atomic force microscopy
(AFM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy
(XPS). AFM and SEM images of modified HOPG with the precursor show particles with
different nanometer sizes. The CoPd2 precursor was thermally reduced under hydrogen
atmosphere, a procedure which removes the organic ligads, forming bimetallic
nanoparticles. The composition of the modified surface described was characterized by
XPS analysis. The presence of precursor and the metals are confirmed on the surface of
Vulcan before and after reduction with XPS analysis.The voltammograms showed that
the CoPd2 precursor is an electroactive species and has different behavior before and after
the reduction process. This study will be essential in catalytic nanoparticles development
for oxygen reduction reaction. We propose an easy and economic methodology for the
nanoparticles formation.
231
Abstracts of the Poster Program (continued)
Poster Session P1
OPTICAL PROPERTIES OF NOBLE METAL NANOPARTICLE FILMS
PRODUCED BY GLANCING ANGLE DEPOSITION
Douglas A. Gish†, Francis Nsiah‡, Mark T. McDermott‡,*, and Michael J.
Brett†,*; †Department of Electrical and Computer Engineering, University of
Alberta, Edmonton, AB T6G 2V4, Canada; [email protected]; ‡ Department
of Chemistry, University of Alberta, Edmonton, AB T6G 2G2 Canada; *
National Institute for Nanotechnology, 11421 Saskatchewan Drive,
Edmonton, AB T6G 2M9, Canada
110
Glancing angle deposition (GLAD) was used to fabricate noble metal nanoparticle films.
Glancing angle deposition is a single-step deposition process utilizing oblique angle
physical vapour deposition combined with precision substrate rotation. Using GLAD, the
morphology of thin films can be tailored on nanometre size scales by exploiting the selfshadowing effects which arise when vapour flux arrives at highly oblique angles to the
substrate surface. This allows for the fabrication of nanoparticle films with designed
particle shapes such as spheres, posts, chevrons, or helices. Thin films consisting of a
dense collection of spherical silver nanoparticles were prepared using GLAD. The
particle diameters ranged from approximately 20 to 300 nm. These films exhibited an
optical extinction peak due to the excitation of localized surface plasmon resonance
(LSPR). The extinction spectra of the films in an air medium exhibited a peak around a
wavelength of 368 nm. This peak was observed to red-shift linearly with increasing
refractive index of the medium surrounding the particles. The refractive index
dependence of the extinction peak position was exploited to detect molecular binding
events at the particle surface. The surface of the particles was functionalized with
solutions of 11-amino-1-undecanethiol and rabbit immunoglobulin G (IgG) to allow for
the detection of anti-rabbit IgG binding. The binding of molecules to the nanoparticle
surface increased the local refractive index near the particle surface, and caused a redshift of the extinction peak. The peak wavelength shift at varying concentrations of antirabbit IgG was measured and fit to the Langmuir isotherm. This yielded approximate
values for the saturation response, Δλmax = 29.4 ± 0.7 nm, and the surface confined
binding constant, Ka = (2.7 ± 0.3) × 106 M−1. The GLAD technique is not limited to
silver, and can be used to fabricate particles out of a variety of different inorganic and
organic materials. Multilayered films consisting of more than one material are also
possible. The properties of a particular organic material, tris-(8-hydroxyquinoline)
aluminum (Alq3), cause it to self-organize into a pseudo-hexagonal array during the
deposition process. By using such a film as a template layer, a similarly ordered array of
noble metal nanoparticles can be fabricated on top of the Alq3 layer. The resulting films
consist of particles with improved uniformity in size, shape, and orientation compared to
films fabricated without the Alq3 template layer, which affects their optical properties.
Poster Session P1
MICROWAVE-POLYOL SYNTHESIS OF TCO NANOCRYSTALS
Elin Hammarberga, Anna Prodi-Schwabb, Claus Feldmanna; aInstitute of
Inorganic Chemistry, University of Karlsruhe (TH), D-76131 Karlsruhe,
Germany; bEvonik Degussa GmbH, Creavis Technologies & Innovation, D45764 Marl, Germany; [email protected]
111
232
Thin films exhibiting a high electrical conductivity and optical transmittance are of major
technical importance in, e.g., solar cells, flat panel displays, and electrochromic devices.
The required combination of properties can be realized by degenerate doping of widebandgap oxide semiconductors, such as In2O3, SnO2, or ZnO. The transparent conductive
oxide (TCO) most widely applied in optoelectronic devices is ITO (In2O3:Sn4+), owing to
an exceptionally high conductivity, combined with a high optical transmittance.
However, research on possible replacement materials is intensive, due to the preciousness
of indium metal. To date, doped ZnO, as well as ternary and quaternary compounds, are
considered promising candidates. TCO films are commonly produced via vacuum-based
gas phase methods, such as magnetron sputtering or chemical vapor deposition. Patterned
structures thereof are normally created via lithographic etching. Altogether, these
manufacturing processes are time-consuming, cost-intensive and produce large amounts
of waste. Here, significant improvements could be realized if instead deposition
techniques such as dip- or spin-coating, ink-jet, off-set, or silk-screen printing were
applied. However, this requires the availability of a suited suspension or ink, containing
nanoscale, non-agglomerated and crystalline TCO particles. Aiming at a facile and lowcost liquid phase synthesis of TCO nanomaterials, we have investigated a microwaveassisted polyol synthesis. Herein, precipitation of oxide nanoparticles occurs via
hydrolysis of a solved metal precursor in a polyol medium. The polyol – a high-boiling
multidentate alcohol such as diethylene glycol (DEG) or glycerine – acts as solvent as
well as surface stabilizer. As a result of the surface stabilization, particle growth and
aggregation are prevented during nucleation and crystallization. This leads to the
formation of non-agglomerated particles, typically 5-50 nm in diameter, with a near
monodisperse size distribution. Due to the high-boiling solvent, well-crystallized
materials can be synthesized at ambient pressure. In addition, the application of
microwave irradiation has turned out to be advantageous with regard to material
crystallinity and particle morphology. Here, our results will be exemplified with the
synthesis of ITO, AZO (ZnO:Al3+), and IZO (ZnO:In3+) nanocrystals in DEG. Size, size
distribution, and crystallinity of as-prepared particles are investigated based on dynamic
light scattering, scanning electron microscopy, transmission electron microscopy, X-ray
diffraction and Brunauer-Emmett-Teller analysis. As-prepared particles turn out to be
single crystalline and exhibit a near monodisperse size distribution. Furthermore, spectral
properties, as well as significant electrical conductivities of powders and thin films will
be presented.
Poster Session P1
SPONTANEOUS STRUCTURE FORMATION ON THE NANO SCALE
Stefan Walheim, Regine Hedderich, Thomas Schimmel, Forschungszentrum
Karlsruhe, Institute for Nanotechnology, POX 3640, D 76021 Karlsruhe,
112
Sharp-edged and well-defined microstructures can be produced by a simple spin coating
process from a polymer solution. Dissolving two immiscible polymers in a common
solvent and subsequent spin-coating the solution leads to phase separation during the
evaporation of the solvent. Both, a lamellar morphology and laterally structured
morphologies are observed, depending on polymer-substate and polymer-polymer
233
interactions. Thus, by controlling the phase distribution, surfaces with tailored properties
can be created. Examples are controlled wetability, tribological and optical properties and
their application as lithography masks. The lateral lengths scale can be adjusted within a
wide range from several micrometers down to the 10 nm scale. By selectively dissolving
one component of the polymer blend film a nanoporous coating is obtained. The
refractive index of our film can be adjusted in a range from 1.6 down to 1.05 by tuning
the composition of the polymer solution. Such films can serve as high-performance antireflection coatings with outstanding optical properties. The undesirable reflection from
glass is reduced by the application of a thin layer; this makes use of the interference at
thin layers. Optimal anti-reflection surfaces for glass require a refractive index n=1.22.
There are however no known traditional materials with a refractive index <1.3. The new
process is simple and economical. The effective refractive index can be precisely
determined by controlling the degree of porosity. Another attraction is that the water sign
on the glass can only be seen in reflection. By the use of micro-contact printing and
scanning probe lithography - the self-organisation of the resulting polymer pattern can be
controlled such that well ordered layout-defined structures can be achieved. An example
of derivatives of these structures are bio-functionalizable structures with laterally defined
spots of only 10 nm in diameter which are fabricated by the combination of polymer
blend lithography and block copolymer nanolithography. Investigations made by in situ
light scattering during the typically five seconds of film formation give insight into the
structure formation process.
Poster Session P1
ROTATIONAL MOULDING OF FIBRE-REINFORCED INTEGRAL SKIN
PE FOAM COMPOSITE
Dylan .D. Jung, D. Bhattacharyya and A. J. Easteal*, Department of
Mechanical Engineering, *Department of Chemistry, The University of
Auckland, Private Bag 92019, Auckland,New Zealand,
[email protected]
113
In the past few years, scientific and industrial research has been increasingly focused on
composite materials comprising wood fibres in thermoplastic matrices, because of their
advantages of lower cost, improved stiffness, and better processibility compared to other
materials. However, the number of potential applications has been limited because of
their low impact strength and high density compared to natural wood and certain plastics.
Recently, the concept of creating microcellular foamed structures in composites through
batch or continuous extrusion processes has been successfully demonstrated to
significantly improve the shortcomings of these composites. Although foam extrusion of
plastic/wood fibre and rotational foaming of neat polymer have been tried, fibrereinforced integral skin foam composites by rotational moulding have not hitherto been
achieved. The research methodology included melt-blending and extrusion of organic and
inorganic fibre incorporated in plastics, grinding the resulting composites to powders, and
rotational moulding of the powders with added chemical blowing agents and catalyst.
Rotational moulding was carried out using a purpose-built laboratory scale machine that
simulates industrial scale rotational moulders, and the mould that was designed using the
Pro-E Engineering software. Mechanical and thermochemical test data for the
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composites are obtained. The morphology characteristics, which affect the final
mechanical properties of the fibre-reinforced integral skin foam composite, will be
presented.
Poster Session P1
STABILITY OF Ag-TiO2 PHOTOCATALYSTS ASSESSED BY A
PHOTOCATALYTIC DEGRADATION OF DICHLOROACETIC ACID
Victor M. Menéndez-Flores1, Donia Friedmann2 and Detlef W.
Bahnemann1; 1Institute for Technical Chemistry, Leibniz Universität
Hannover, Callinstr. 3, D-30167Hannover, Germany; 2Interdisciplinary
Nanoscience Center University of Aarhus, Building 520, Room 128, Ny
Munkegade, 8000 Aarhus C, Denmark; [email protected]
114
The photocatalytic activity of Ag+ ions at the surface of commercialy available as well as
self-prepared TiO2 particles has been investigated in consecutive runs for the degradation
of dichloroacetic acid (DCA). The photodegradation of 1 mM of DCA was realized
employing a concentration of 0,5g L-1 of photocatalyst in a reactor (50 mL) with a plain
quartz window on which the light beam (λ ≥ 320 nm) is focused. The reactor is equipped
with a magnetic stirring bar, a water-circulating jacket and three openings for electrode,
gas supply, and sample withdrawing. The investigation was performed to compare the
catalyst performance at different silver loadings (from 0 to 2 atom % silver) and at two
different pH conditions: pH 3 and pH 10. The highest photocatalytic efficiency (ζ = 3.37)
was observed with the 0.2 atom % Ag-P25 TiO2 at pH 3 and with colloidal TiO2
photocatalyst which were the most resilient to deactivation by the Cl- ions at pH 3. This is
believed to be due to the greater number of active sites in the latter sample. The
degradation was followed by TOC measurements and by the calculation of the photonic
efficiency from the initial rate of the H+ ion formation under pH-stat reaction condition.
Reusing Ag-P25 TiO2 photocatalyst for three consecutive degradation runs within twelve
hours, does not reveal any permanent negative effect on the photocatalyst performance.
In any case, the photoactivity of the catalysts was observed to be easily recovered by a
simple washing technique.
Poster Session P1
STOP-FLOW LITHOGRAPHY OF COLLOIDAL, GLASS, AND SILICON
MICROCOMPONENTS
Robert F Shepherd1, Priyadarshi Panda2, Zhihao Bao3, Kenneth H
Sandhage3, T Alan Hatton2, Jennifer A Lewis1 and Patrick S Doyle2, 1
Department of Material Science and Engineering, University of Illinois,, U-C,
1304 W Green St.,Urbana, IL 61801, 2 Department of Chemical Engineering,
Massachusetts Institute of Technology, 77 Massachusetts Avenue,
Cambridge, MA 02139, 3 Department of Material Science and Engineering,
Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA 30332, USA;
[email protected] and [email protected]; [email protected]
115
The assembly of oxide and non-oxide microcomponents from colloidal building blocks is
235
central to a broad array of applications, including sensors, optical devices, and
microelectromechanical systems (MEMS), as well as to fundamental studies of granular
materials. Progress in these areas has been hindered by the availability of colloidal
microcomponents of precisely tailored size, shape, and composition. Here, we report a
method for patterning colloidal building blocks into controlled structures via stop-flow
lithography (SFL). Microcomponents are created at rates that exceed 103 min-1 in both
simple and complex, i.e., microgear, shapes using an index-matched system composed of
silica microspheres suspended in a photocurable acrylamide solution. Upon drying, the
resulting colloidal structures are akin to non-spherical granular media. These structures
are then transformed at elevated temperatures into microcomponents composed of porous
or dense glassy oxides or porous silicon via magnesiothermic reduction. The SFL
method provides the exquisite control over component size, shape, and composition
needed to enable fundamental and technological advances in wide variety of fields.
Poster Session P1
116
SYNTHESIS OF POROUS ANATASE NANOPARTICLES AND Au/TIO2
NANOMATERIALS BY MINIEMULSION TECHNIQUE
Renate Rossmanitha, Clemens K. Weissa, Katharina Landfestera, Jasmin
Geserickb, Nicola Hüsingb ; a) Institute of Organic Chemistry
III/Macromolecular Chemistry and Organic Materials, Ulm University,
Albert-Einstein-Allee 11, 89081 Ulm, Germany; [email protected]; b) Institute of Inorganic Chemistry I, Ulm University, Albert-EinsteinAllee 11, 89081 Ulm, Germany
Porous anatase nanoparticles with high specific surface area have many potential
applications for example as catalyst support or as electrodes in lithium ion batteries.
However, the applications depend strongly on the particle size and their crystalline
structure. Highly dispersed Au/TiO2 catalysts are of great interest in many oxidation and
reduction reactions for example the low temperature CO oxidation. Here we report a
novel template-free approach to synthesize porous anatase nanoparticles. By combining
the sol-gel process with the inverse miniemulsion technique spherical particles of about
200 nm were prepared which consist of aggregated small anatase crystallites of several
nanometers in size with a specific surface area of more than 300 m²/g after calcination at
400 °C. The only employed surfactant is a block copolymer (P(E/B-b-EO)) which
stabilizes the aqueous droplets with the water-soluble precursor bis(2-hydroxyethyl)
titanate (EGMT) in the organic phase. The miniemulsion technique is of advantage
because it produces small monodisperse droplets in which hydrolysis and condensation to
the final TiO2 particles takes place. During the reaction each droplet acts as a nanoreactor
under preservation of droplet size, droplet number and the concentration in each droplet.
Therefore, the particle size can be easily tuned in a wide range. For the synthesis of
Au/TiO2 nanomaterials Au was introduced both in-situ and after synthesis by depositionprecipitation process. HAuCl4 as the gold source was reduced by temperature or addition
of an reducing agent. The obtained powders were characterized by transmission (TEM)
and scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen sorption
(BET).
236
Poster Session P1
NANOPARTICLE SIZE-SELECTIVE FRACTIONATION PROCESS
USING CO2-EXPANDED LIQUIDS AT DIFFERENT PROCESSING
SCALES
Steven R. Saunders1, Madhu Anand2, Christopher B. Roberts1. (1)
Department of Chemical Engineering, Auburn University, 212 Ross Hall,
Auburn, AL 36849. (2) Conoco Philips Company, 333 PL Bartlesville
Technology Center, Highway 60 & 123, Bartlesville, OK 74004, USA;
[email protected], [email protected].
117
We have recently scaled up a process that allows for the size-selective fractionation of
ligand-stabilized metal and semiconductor nanoparticles that utilizes the pressure tunable
physico-chemical properties of CO2 gas expanded liquids (GXL’s). The nanoparticle size
separation technique is based on the controlled reduction of the solvent strength of
organic phase nanoparticle dispersions through increases in concentration of the antisolvent CO2 via pressurization. These changes in solvent strength affect the subtle
balance between the osmotic repulsive forces (due to the solvation of the stabilizing
nanoparticle ligand tails) and the van der Waals forces of attraction between different
sized particles necessary to maintain a stable dispersion. Through modest changes in
CO2 pressure, increasingly smaller sized nanoparticles can be controllably precipitated
from the dispersion, resulting in the separation of particle dispersions typically ranging
from 2nm to 12 nm into ±1nm fractions. Recently, we have demonstrated an effective
separation of metal (Au and Ag) and semiconductor (CdSe/ZnS) nanoparticles using a
novel glass spiral tube apparatus within a high pressure vessel. However, this initial
apparatus was only capable of separating approximately 200 μL (2 mg) of a nanoparticle
dispersion. It is desirable to design a new apparatus capable of processing larger
quantities of monodisperse nanoparticles for applications in catalysis, sensors,
semiconductors, and optics. This new scaled up apparatus consists of three vertically
mounted high pressure vessels connected in series with high pressure needle valves that
allow for sequential isolation and separation of the fractionated nanoparticle dispersions.
This process, operated at room temperature and CO2 pressures between 28 bar and 49
bar, can result in a batch or semi-continuous size selective separation of approximately 20
mL of a concentrated (20 mg/mL) nanoparticle dispersion, a scale up factor of 200 over
the previous process. Performing separations at this scale illustrates that it is possible to
separate large quantities of nanoparticle dispersions using this technique. This process
can be easily modified by increasing the number of fractionation vessels, by increasing
the size of the vessels, by adjusting the ΔP at each stage, or through changes in ligand
type or solvent choice. The efficiency of separation of several nanoparticle systems (Ag,
Au, and Pt) will be presented including the effects of different nanoparticle ligands and
adjusting other design parameters.
Poster Session P1
LUMINESCENCE AND AMPLIFIED STIMULATED EMISSION OF
CdSe@ZnS QUANTUM DOTS DOPED TiO2 AND ZrO2 WAVEGUIDES
A. Martucci1, J. Jasieniak2, P. Mulvaney2, R. Signorini3; 1 Dipartimento di
118
237
Ingegneria Meccanica Settore Materiali, Universita' di Padova, Italy
[email protected]; 2 University of Melbourne, School of Chemistry,
Parkville, Victoria, 3010, Australia; 3 Dipartimento di Scienze Chimiche,
Universita’ di Padova, Italy; [email protected]
Sol-gel titania and zirconia waveguides doped with high-quality CdSe@ZnS core-shell
quantum dots have been synthesized. The optical properties of the nanocomposite thin
film were found to be sensitive to the semiconducting properties of the host matrix.
Titania films were seen to be inherently photo-unstable due to photoelectron injection
into the bulk matrix and subsequent nanocrystal oxidation. In comparison, zirconia films
were significantly more robust with high PL retained for annealing temperatures up to
300 oC. Both titania and zirconia composite waveguides exhibited amplified stimulated
emission (ASE); however only zirconia based waveguides exhibited long term
photostability (loss of less than 30% ASE intensity after more than 40 minutes
continuous excitation). We conclude that the low electron affinity of zirconia and its
inherent high refractive index makes it an ideal candidate for nanocrystal based optical
waveguides.
Poster Session P1
ZINC OXIDE NANOROD SYNTHESIS FROM NANOPARTICLES IN 1,4
BUTANEDIOL SOLVENT
Nelson S. Bell and D.R. Tallant, Sandia National Laboratories, P.O. Box
5800-1411, Albuquerque, NM 87185, USA; [email protected]
119
Particle synthesis and shape control are sensitive processes affected by solvent, reaction
material, and processing methodology. Control of morphology requires understanding of
the reaction mechanisms inherent in a system, as well as how chemical agents can be
used to direct the growth of the desired material. Zinc oxide nanorod formation in 1,4butanediol was studied as a function of time and temperature using TEM, UV-vis
absorption spectra, and photoluminescence. These observations show that ZnO is the
stable phase for precipitation using the sol-gel process reaction of refluxed zinc acetate
with base, that growth and ripening of nanodots proceeds via the LSW model of particle
coarsening, and that ripening at elevated temperature leads a transition to nanorod
morphologies. The use of 1,4-butanediol allows for higher temperature reaction than in
alcohols, and therefore does not require the use of pressure vessels. However, at higher
temperatures, 1,4-butanediol is susceptible to degredation, leading to cessation of the
ripening phenomenon. Sandia is a multiprogram laboratory operated by Sandia
Corporation, a Lockheed Martin Company, for the United States Department of Energy’s
National Nuclear Security Administration under contract DE-AC04-94-AL85000.
Poster Session P1
SYNTHESIS AND CHARACTERIZATION OF GERMANIUM
CHALCOGENIDE NANOPARTICLES
Marissa Caldwell1, Simone Raoux2, Delia Milliron2, and H.-S. Philip
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Wong3; Departments of Chemistry1 and Electrical Engineering3 Stanford
University, Stanford CA; 2IBM Almaden Research Center, San Jose CA;
[email protected]
While volumes of literature exist on the controlled synthesis of colloidal metal
chalcogenide nanoparticles, there have been relatively few reports on the synthesis of
colloids containing main group metal chalcogenides. In particular, the germanium
chalcogenides exhibit much electronic and structural diversity including: germanium ions
in the II and IV oxidation state, numerous observed crystal structures, and the possibility
of high amorphous state stability. We will report on our recent work exploring a range of
synthetic approaches to controllably synthesize materials in this class. First, germanium
selenide nanoparticles have been synthesized using a novel class of molecular singlesource precursors. These precursors contain pre-formed metal-chalcogen bonds and
decompose at low temperature to facilitate nanoparticle formation. As synthesized, the
ethylhexanoic acid capped germanium selenide nanoparticles are crystalline and exhibit
quantum size effects in their optical spectra. Second, we have developed a route to
germanium(II) chalcogenide nanoparticles using separate precursors for the metal and
chalcogen. Using this co-precipitation approach, we report for the first time the synthesis
and characterization of germanium telluride nanoparticles. Taking advantage of the
multiple stable solid-state phases of germanium telluride, we will also report preliminary
results on the phase transitions of small (~3nm) particles.
Poster Session P1
SYNTHESIS AND ELECTROCATALYTIC ACTIVITY OF Pt/Co3O4
NANOCOMPOSITE
Youcun Chen, Lin Hu and Yulin Min, Anhui Key Laboratory of Functional
Coordination Compounds, School of Chemistry and Chemical Engineering,
Anqing Normal University, Anqing 246011, P. R. China;
[email protected]
121
Three-dimension (3D) flowerlike Co3O4 microspheres were synthesized in glycol (EG)
system by self-assembled with nanoslices in the absence of any template and surfactant.
The Brunauer-Emmett (BET) gas sorptometry measurement showed that the Co3O4
microspheres were porous with two narrow porous volume distributions. Pt/Co3O4
nanocomposites were achieved by the reduction of H2PtCl6 with glucose by refluxing in
the presence of porous Co3O4 microspheres. The size and size distribution of Pt
nanoparticles in Pt/Co3O4 nanocomposites could be controlled by changing the mole ratio
of platinum salt in solution and the reaction time. The glucose acts as not only reductant
but also stabilizer which can prevent particle agglomeration. Pt/Co3O4 composite
electrode possesses higher catalytic activity for methanol oxidation compared with Pt
electrode, which will have promising applications in fuel cells and catalysis.
239
Poster Session P1
ULTRASMALL MAGIC-SIZE CdSe NANOCRYSTALS: SYNTHESIS,
CHEMISTRY AND OPTICAL PROPERTIES
Minho Jung, Teri Schweers and Gregory Kalyuzhny, Department of
Chemistry and Biochemistry, San Diego State University, 5500 Campanile
Dr., San Diego, CA 92182-1030, USA; [email protected]
122
The synthesis, chemical and optical properties of ultrasmall magic-size CdSe
nanocrystals (NCs) are reported. Various synthetic procedures were shown to produce
NCs with similar optical properties implying that the particles with the same “magic” size
are obtained. Solutions of the CdSe NCs in various non-polar solvents emit white-yellow
light due to the large amount surface states but loose most of their emission upon transfer
to aqueous phase by ligand exchange reactions.
Poster Session P1
CHARACTERIZATION OF ZnS NANOPARTICLES PREPARED BY A
FAST AND FACILE SYNTHESIS ROUTE
Gabriele Kremser, Andreas Pein, Ilse Letofsky-Papst, Birgit Kunert, Roland
Resel and Gregor Trimmel, Institute for Chemistry and Technology of
Organic Materials, Graz University of Technology, Graz, Austria;
[email protected]
123
Nanocrystalline materials have attracted much attention due to their unique sizedependent thermal, optical, electronic, magnetic and mechanical properties that differ
significantly from their bulk characteristics. Zinc sulfide is one of the most important
II-VI semiconductors providing a high potential in many different technological
applications, e.g. as photonic crystals or in optoelectronic devices. In this contribution we
report a modified synthesis route for the preparation of nanocrystalline cubic ZnS
particles. Starting from zinc chloride, sulphur and different alkyl amines (oleylamine,
dodecylamine, propylamine) the particles were synthesized within a short reaction time
of typically 90 min. The amines act as capper and prevent agglomeration of the
nanocrystals. The so prepared particles exhibit the cubic sphalerite structure as
determined by X-ray diffraction (XRD). Transmission electron microscopy (TEM)
shows a homogeneous size distribution with mean particles sizes of approximately 3 to 5
nm. The high crytallinity was confirmed by high resolution TEM. The optical properties
were investigated with UV-vis and photoluminescence spectroscopy. The nanoparticles
obtained with oleylamine and dodecylamine are still soluble in organic solvents (e.g.
hexane), whereas the synthesis with propylamine yields aggregated powders. Dynamic
light scattering measurements revealed that the primary crystallites tend to aggregate in
solution, which was further investigated by small angle X-ray scattering experiments.
Poster Session P1
SYNTHESIS OF CRYSTALLINE RARE EARTH DOPED CERIA NANOSPHEROIDS
Mangalaraja R.V., Romel M. Jiméneza, Carlos P.Camurri, Ananthakumar.
Sb; Department of Materials Engineering, University of Concepción,
Concepción, Chile; a Department of Chemical Engineering, University of
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Concepción, Chile; bNational Institute for Interdisciplinary Science and
Technology (NIIST), CSIR, Trivandrum- 695 019, Kerala, India;
[email protected]
Crystalline ceria nano-spheroids doped with gadolinium (Gd), Samarium (Sm),
Neodymium (Nd) and Yttrium (Y) have been synthesized through modified nitrate-fuel
combustion method in which ammonium sulphate is employed as shape forming agent.
The as-prepared precursor powders were characterized for TG/DTA and FTIR analyses.
Rare earth doped ceria nano-spheroids with an average size ranging from 10-25nm are
achieved when the as-prepared powder is calcined at 700°C for 2h. The results show that
the nano-spheroids are highly crystalline, loosely agglomerated and homogeneous in
nature. The effect of sulphate addition on the morphological features, crystallinity,
specific surface area and particle size are analyzed.
Poster Session P1 – Invited Poster
LIQUID PHASE MORPHOLOGY CONTROL OF ANISOTROPIC OXIDE
PARTICLES – TiO2, ZnO, BaTiO3Yoshitake Masuda, National Institute of Advanced Industrial Science and
Technology (AIST), Moriyama, Nagoya, 463-8560, Japan;
[email protected]
125
Anatase TiO2 particles, 100–200 nm in diameter, were developed in aqueous solution at
50°C. The particles were assemblies of nano TiO2 crystals covered with nanorelief
surface structures. The crystals grew anisotropically along the c-axis to form acicular
crystals. The particles showed c-axis orientation due to high-intensity X-ray diffraction
from the (004) planes. The particles had a BET specific surface area of 270 m2/g. BJH
and DFT/Monte-Carlo analysis of adsorption isotherm indicated the existence of pores ~3
nm and ~1 nm in diameter. Crystallization and self-assembly of nano TiO2 were
effectively utilized to fabricate nanocrystal assembled TiO2 particles having high surface
area and nanorelief surface structure. An aqueous solution system was developed to
control the nucleation and crystal growth of ZnO. Ethylenediamine was used to promote
deposition of ZnO from zinc acetate solution. Crystalline ZnO particles or particulate
films were successfully fabricated at 60 °C. The morphology of ZnO particles was further
controlled to a hexagonal cylinder shape, long ellipse shape or hexagonal symmetry
radial whiskers having high aspect ratio. The morphology was controlled by changing the
supersaturation degree. Moreover, their photoluminescence was investigated. The novel
solution process will contribute to the development of future ZnO devices. We developed
acicular BaTiO3 particles, achieved by controlling the morphology of BaC2O4 • 0.5H2O
to acicular shape and its phase transition to BaTiO3 by introducing Ti ions from the
coprecipitated amorphous phase. Acicular BaTiO3 particles have an aspect ratio as high
as 18 and the particle size can be controlled by varying the growth period of BaC2O4 •
0.5H2O which governs the size of BaC2O4 • 0.5H2O particles. Acicular particles of
crystalline BaTiO3 can be used for ultra-thin multilayer ceramic capacitors. We further
proposed a novel concept for morphology control of barium titanate precursor to fabricate
platy particles. Organic molecules play essential role in crystallization of BaTiOF4 to
synthesize multi-needle particles, polyhedron particles or platy particles in an aqueous
241
solution. Precursors were successfully transformed to barium titanate single phase by the
annealing. Platy barium titanate precursor particles are expected for future multilayer
ceramic capacitors. The scientific novel concept for crystallization control and particle
morphology control would contribute to the development of future nanocrystals and
nanodevices using bio-inspired organic-inorganic interactions.
Poster Session P1
CONTINUOUS HYDROTHERMAL SYNTHESIS OF NANOMETRIC
OXIDES IN SUPERCRITICAL CONDITIONS
N. Millot, M. Ariane, L. Saviot and D. Aymes, Institut Carnot de Bourgogne,
UMR 5209 CNRS/Université de Bourgogne, BP 47870, 21078 Dijon cedex,
126
Due to the size dependence of the properties of nanoparticles, nanostructured oxides are
currently drawing the attention of industries and scientists for electronic and biomedical
applications. To be applicable at the industrial level, continuous synthesis technologies
allowing the production of several tens of grams per hour are required. Such a continuous
production prototype for hydrothermal synthesis in subcritical and supercritical water has
been developed in our group. In this poster, the synthesis of TiO2, γ-Fe2O3, Fe2CoO4,
BaFe12O19 and BaZrO3 nanopowders will be presented. The as-prepared powders are
characterized by complementary techniques such as XRD, electron microscopy and
spectroscopic methods (Raman, XPS, EDXS, IR). As a result, the size, morphology,
aggregation state, crystal structure, bulk and surface composition of the particles are
investigated. Due to the very short residence-time in the reactor (less than 10 s), the size
of the particles and the size distribution are smaller and narrower than those of powders
obtained with usual routes (soft chemistry and hydrothermal synthesis in batch reactors).
The other advantages of this process are its versatility, its productivity (thanks to the
continuous running), and the possibility of industrial-scale synthesis of controlled
nanoparticles in a wide range of experimental conditions.
Poster Session P1
NONAQUEOUS SOL-GEL ROUTES TO METAL-OXIDE
NANOCRYSTALS, HYBRID MATERIALS AND THIN FILMS
Nicola Pinna, Department of Chemistry and CICECO, University of Aveiro,
3810-193 Aveiro, Portugal; [email protected]
127
Non-aqueous sol-gel routes are elegant approaches for the synthesis of nanomaterials.
Here, it will be shown that these approaches were successfully used for the formation of
high quality pure inorganic nanocrystals, ordered hybrid organic-inorganic materials and
thin films by atomic layer deposition. Especially, the chemical mechanisms taking place
during the metal oxide formation greatly influence the morphology, assembly and the
final properties. Several different aspects of these approaches will be discussed: (1) The
peculiar structure and the formation mechanism of organic-inorganic hybrid materials
will be detailed and correlated to their properties. Especially, the optical properties of
lanthanide doped hybrid materials strongly depend on the organic moieties forming the
242
hybrid mesostructure. (2) Pure semi-conducting metal oxide nanoparticles synthesized in
non-aqueous media without the need of surfactants are good candidates for resistive gas
sensor devices due to their nanometric size, good crystallinity and high purity. Selected
examples of gas sensor fabricated with porous thick layers made of nanoparticles will be
presented. (3) Finally, the transposition of similar non-aqueous sol-gel approaches to the
deposition by atomic layer deposition of thin films on several substrates including carbon
nanotubes, silicon wafers or organic fibers will be discussed.
Poster Session P1
POLYCAPROLACTONE NANOPARTICLES AS RESVERATROL
CARRIER SYSTEMS; EFFECT OF DISPERSED PHASE SOLVENT ON
PROPERTIES OF NANOPARTICLES PREPARED BY EMULSION
SOLVENT EVAPORATION METHOD
Bum-Keun Kim, Jun-Soo Lee, Yong-Jin Cho, Dong-June Park*; Korea
Food Research Institute, 516, Baekhyun-Dong, Bundang-Ku, Songnam-Si,
Kyunggi-Do, 463,746, Korea; [email protected]; [email protected]
128
Resveratrol-loaded poly(ε-caprolactone) nanoparticles were prepared by o/w emulsion
solvent evaporation method. The features of this process was the use of two solvents
(termed as ‘mixed solvent system’ or MSS here) as a dispersed medium (Viswanathan et
al., 1999; Kim et al., 2002). The mean particle size of nanoparticles prepared using only
DCM (523.45±36.7nm) was larger than that prepared with a mixture of DCM and either
EtOH (494.50±29.15nm) or Acetone (493.53±6.93nm). Evaporation through the aqueous
phase depends on the solubility of the solvents in water (Kim et al., 2005) rather than
boiling point. Practically, although boiling point of DCM (39.8ºC) is lower than those of
acetone (56.5 ºC) and EtOH (78.5 ºC), water solubility of DCM is in the range
DCM acetone or EtOH (miscible). Therefore the rate of precipitation is in the same
range. Since the higher the water solubility, the higher the diffusion rate before
nanoparticle hardening. This is the major reason of smaller mean size of nanoparticles.
Sah (2000) also showed that, although boiling point of the DCM is a little higher than
that of ethyl formate, the high evaporating rate is contributed to the difference in water
solubility. The differences in the evaporation rate of solvents may have influence on the
encapsulation efficiency of the nanoparticles. The encapsulation efficiency of
nanoparticles prepared only with DCM as dispersed phase (78.29±7.74%) was the
highest of those prepared with solvent mixtures. These are also related to the water
solubility of the solvents. Generally, core partitioning into the aqueous phase can occur
during the initial stages of nanoparticle formation prior to polymer precipitation. During
evaporation of the solvent from the aqueous phase, the core materials can be migrated
with solvent into aqueous phase. So, the higher the evaporation rate, the lower the
encapsulation efficiency of the nanoparticles, which was the similar results of our
previous study (Kim et al., 2005). However, in morphological analysis, no particular
differences could be observed. These results indicate that dispersed phase solvent is one
of the most important factors that affect the properties of resveratrol-loaded PCL
nanoparticles; therefore mean particle size and encapsulation efficiency could be
controlled by changing the dispersed phase solvent component.
243
Poster Session P1
ENZYMATIC SYNTHESIS OF LAYERED DOUBLE HYDROXIDES
Vanessa Prevot, Stéphanie Vial, F. Leroux, Claude Forano; Laboratoire des
Matériaux Inorganiques, Université Blaise Pascal, UMR 6002, 24 Avenue des
Landais, 63177 Aubière Cedex, France, [email protected]
129
Biomineralization is a natural process which offers the opportunity to produce highly
organized nanocomposite multiscale structures, from the atomic to the macroscopic level
for a wide range of compositions. Recently, enzymatically assisted routes has been
reported to fabricate materials with excellent control of the structural organization. Here,
a biomineralization process based on the enzyme-catalyzed decomposition of urea by
urease is presented as a novel approach to prepare Layered Double Hydroxides (LDHs).
LDH are simple layered structures built on a stacking of positive [MII1-xMIIIx(OH)2] x+
sheets interlayered by solvated anions [Aq-x/q.nH2O], which display typical hexagonal
platelets. LDH materials have been extensively studied since many years because of their
wide potentialities of applications for examples in catalysis, adsorption/separation,
medicine and elaboration of new nanocomposites. However, many of these uses are
restricted because of the limited accessibility to both the internal galeries and the outer
surface. The control of particle size and shape, number of stacked layers, type of platelets
aggregation, porosity is a great challenge in order to prepare LDHs with specific textural
properties and reproducible physico-chemical properties. Using biomineralization
conditions, a large series of LDH materials (ZnAl, MgAl, NiAl, ZnCr, CuCr) can be
prepared. In such conditions, urease, an enzyme extracted from Jack Bean, catalyses
under kinetic control at room temperature, the decomposition of urea into ammonium
carbonate allowing the biogenesis of the LDH minerals to occur at the surface of the
biomolecules. The crystal growth of LDH particles is kinetically limited in such
conditions compared to the so called urea method based on the thermal decomposition of
urea (90°C). Effect of the enzymatic reaction parameters (urease activity, urea
concentration…) will be detailled in comparison with materials obtained by precipitation
based on the thermal decomposition of urea. Finally, the enzymatic synthetic route is also
a way to immobilize urease in LDH which is of interest for urea biosensors elaboration
and will be compared to other soft chemistry immobilization methods such as
coprecipitation, adsorption and delamination/restacking.
Poster Session P1
SOLVENT INFLUENCE ON PALLADIUM NANOPARTICLE
SYNTHESIS
Rocío Redón, Samantha K. Rendón-Lara, Ana L. Vargas-Osoriob José M.
Saniger; Lab. de Materiales y Nanotecnología, CCADET, Universidad
Nacional Autónoma de México, Mexico City, 04510, México; bFESCuautitlán, Universidad Nacional Autónoma de México, Edo. de Mexico,
México; [email protected]
130
Nanoscale materials have being widely studied because of their particular properties and
potential applications. In particular, noble metal nanoparticles have been used as catalysts
244
and photo catalysts in solution for many years. The activity of these materials is
associated to their size, crystal structure and the nature of the stabilizer. Being the
purpose of the stabilizer to control the particle size and to prevent the agglomeration. In
the present work we would like to present the results of the study of different solvents
dependence on the size and/or morphology of palladium nanoparticles. Thus, the study is
based on the effect of different solvents on the reduction and stabilization of metal
nanoparticles. In this particular case, DMSO, DMF, etilen glycol Ethanol and H2O are
the employed solvents, and the reduction methods include atmospheric O2,
fotorreduction, sodium citrate, sodium borohydride and ultrasound irradiation. By TEM
micrographs and UV-vis spectrum analysis it can be said that the biggest particles
obtained come from the reduction with sodium citrate, meanwhile the particles obtained
from reduction with borohydride affords the smallest ones. On the other hand, when
ultrasonic method is used, the particles obtained are the most irregular with plenty of
unsaturated sites, an excellent characteristic for their use as catalysts. With these results,
it can be said that the reduction method plays an important role on the size and shape of
palladium nanoparticles and can be designed just by the choice of the correct one for the
desired purpose.
Poster Session P1
SPECTROSCOPIC STUDY OF BiFeO3 AND YFeO3 NANOCRYSTALS
PRODUCED BY A SOLVENT-FREE METHOD
America Vazquez-Olmos, Ruben Armendariz-Martinez, Ana L. FernandezOsorio, Roberto Sato-Berru and Esther Mata-Zamora. Center of Applied
Sciences and Technological Development. Universidad Nacional Autonoma
de Mexico, Coyoacan 04510, Mexico; [email protected]
131
Multiferroics are one class of general magnetoelectric materials wherein magnetic and
electric polarizations are strongly coupled. These materials offer unique opportunities to
study fundamental physical links between spin, charge and lattice degrees of freedom.
They will also offer the singular ability to control or sense the material polarization state
with either electric or magnetic field, a particular flexibility that may prove
technologically relevant for a number of applications, since the development of nextgeneration materials relies on the ability to control function. In this work, BiFeO3 and
YFeO3 nanocrystals have been successfully synthesized via an uncomplicated
mechanochemical solvent-free method, starting from their acetate or chloride salts in
presence of sodium hydroxide. Their crystalline structures and their average diameters
between 8 and 12 nm, were determined from XRD patterns and by HR-TEM images.
Particle sizes were controlled through the concentration of starting materials and heating
temperature. The UV-visible electronic absorption, Raman spectroscopy and electronic
paramagnetic resonance spectra show clear evidence of the quantum size effect. The
magnetic study of these systems is in progress.
245
Poster Session P1
NEW ELECTROSTATIC DISPERSION METHOD DISPERSING FINE
POWDER IN AIR
Zheng Xu1 and Shouci Lu2; 1General research institute for nonferrous metals,
Beijing, 100088, China. Email: [email protected]; 2Civil and Environmental
School of University of Science and Technology, Beijing, 100083, China;
[email protected]
132
Powder materials are widely used in the industries. The finer the powder is, the better the
material’s performance is. But as the powder size become finer, the agglomeration of the
powder becomes more severe. This is very harmful to the use of powder. To reduce the
agglomeration, a new electrostatic dispersion device is designed. This device is use the
repulse force between particles which charged the same charge to prevent the particles
from reuniting. The effect of charge voltage, particle size, the distant between electrode,
humidity of the powder and the invalidation time on the dispersion degree of powder are
given in this paper. It is proved that the electrostatic dispersion is a new effective method.
The charge voltage is the most important role affecting the dispersion. Middle size
particle got best dispersion. When the distance between the electrodes is 24cm, the
dispersion degree reaches the maximum. The humidity of the powder not only affects the
charge of the powder, but also affects the dispersion degree of the powder. This method
will give promotion to the powder application in many industries.
Poster Session P1
CONTROLLED SEDIMENTATION OF CONCENTRATED COLLOIDAL
SUSPENSIONS
M. Abubakar,a* M. A. Faers b , and P. F. Luckham a ; (a) Department of
Chemical Engineering, Imperial College, London SW7 2BY, UK, (b) Bayer
CropScience , Monheim, Germany; [email protected]
133
In this work we focus on a discussion of sedimentation behaviour of weakly flocculated
systems. The sedimentation behaviour of colloidal suspensions of a commercial
fungicide, tebuconazole, at three different particle volume fractions has been determined.
The particles have been weakly flocculated with non-adsorbing polymers that acted as
depletion flocculants. Three different polymer systems have been used to achieve this,
hydroxyethyl cellulose (HEC) with low and high molecular weights (Mw) of 0.3x106 and
1x106 respectively and xanthan with a very high Mw of approximately 2x106 g/mol. The
sedimentation was monitored by determining the volume fraction-height profiles from
ultrasound velocity measurements through the dispersions. The advantages of this
method are twofold, firstly it is non invasive and secondly it can monitor the behaviour
within the opaque sediment in addition to the supernatant interface. From this work we
have established that the three most influential factors governing the sedimentation rate
seem to be particle volume fraction, the concentration of the non-adsorbing polymer and
molecular weight of the non-adsorbing polymer. At relatively low polymer concentration
rapid sedimentation is observed due to “Stokes clusters,” which enhance the
246
sedimentation rate. However, as the polymer concentration increases the sedimentation
rate decreases and is finally hindered by the formation of a continuous rigid network of
particles. This 3-D network is able to support itself and hence control sedimentation. In
this region at a low particle volume fraction of 0.2, sedimentation produced a clear
supernatant with dense sediments at the base of the samples. This was found for all three
polymer MW's and was consistent with both Stokes and consolidation processes. For the
suspensions at high volume fractions, a gradual compaction of the suspension throughout
its entire height was generally observed without a hard sediment at the base. Transient gel
behaviour was observed with the sedimentation rate increasing after a period of hours to
days, depending on the polymer concentration. The polymer MW had a strong effect on
the sedimentation, with higher Mw polymers giving much slower sedimentation. This
Mw effect was seen with the rheology also. For corresponding sedimentation velocities,
the lower MW samples showed much higher elastic modulus and extrapolated yield stress
values in accord with previous observations. This difference was considered to be a
consequence of the time taken for the polymer chains to diffuse through the particle
network, with larger chains diffusing much more slowly. Hence, a stronger network that
can support itself is required when the polymer Mw is small while for large polymers
only a weak network is necessary. The results obtained suggest that there is a strong link
between the rheology and sedimentation behaviour of the suspensions for the individual
polymers used and provide a new insight into the behaviour of the weakly flocculated
systems and their link with rheology.
Poster Session P1
ULTRASONIC PULSED DOPPLER (USPD): A NOVEL METHOD FOR
THE CHARACTERIZATION OF PARTICLE AND NANOPARTICLE
SUSPENSIONS
Steven Africk, Prodyne Corp., Waban MA 02468 and Massachusetts
Institute of Technology, Cambridge MA 02139; [email protected]
134
USPD is a novel technique using ultrasonic backscatter for the characterization of
suspensions of particles and nanoparticles. It has demonstrated the ability to characterize
particles of size from 120 µm to less than ten nanometers. Particles measured include
Islets of Langerhans, beta cells, polymer nanoparticle beads, TiO2 colloids, dendrimers,
nanoparticle inks and protein molecules. Measurements include particle concentration,
size, and physical properties (e.g. compressibility). The system can also detect largeparticle contamination of suspension of smaller particles. Using only a single focused
transducer, the method is simpler than standard ultrasonic techniques and can readily be
employed for batch measurements and incorporated into existing analytical devices or
process equipment for online process monitoring. Recent measurements include
reduction in backscatter from SDS micelles associated with the uptake of palmitic acid
‘cargo’ and increased backscatter due to the expansion of BSA protein with decreased
pH. Preliminary measurements suggest the possibility of measuring particle size with
precision far greater than is possible with light scattering in the nanometer range.
Another recent development is the incorporation of the entire USPD electronic system
into a very inexpense10 in3 package.
247
Poster Session P1
SIZE DISTRIBUTION OF SUPERPARAMAGNETIC PARTICLES AND
CLUSTERSDETERMINED BY MAGNETIC SEDIMENTATION
J.-F. Berret¹, O. Sandre², and A. Mauger³; ¹Matière et Systèmes Complexes,
UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet
10 rue Alice Domon et Léonie Duquet, 75205 Paris, France; ² Laboratoire
Liquides Ioniques et Interfaces Chargées, UMR 7612 CNRS Université Pierre
et Marie CurieParis-VI, 4 place Jussieu, F-75252 Paris Cedex 05, France;
³ Département Mathématique Informatique Physique Planète et Univers, 140
rue de Lourmel, F-75015 Paris, France;
[email protected]
135
We report on the use of magnetic sedimentation as a means to determine the size
distribution of dispersed magnetic particles. The particles investigated here are i) single
anionic and cationic nanoparticles of diameter D ~ 7 nm and ii) nanoparticle clusters
resulting from electrostatic complexation with polyelectrolytes and polyelectrolyteneutral copolymers. A theoretical expression of the sedimentation concentration profiles
at the steady state is proposed and it is found to describe accurately the experimental data.
When compared to dynamic light scattering, vibrating sample magnetometry and
cryogenic transmission electron microscopy, magnetic sedimentation exhibits a unique
property : it provides the core size and core size distribution of nanoparticle aggregates.
Poster Session P1
SURFACE ENERGY DISTRIBUTION ON THE SURFACE OF MILLED
AND CRYSTALLISED LACTOSE
Majid Naderi, Frank Theilmann and Daniel J. Burnett, Surface Measurement
Systems, Ltd., Allentown, PA 18103, USA; [email protected]
136
The processing and performance of dry powder inhalation (DPI) formulations depends
strongly on the interaction at the interface of the different compounds. This interaction is
affected by the surface heterogeneity. Surface heterogeneity can express itself in various
forms, such as porosity, surface roughness (rugosity) and distribution of surface energy.
The latter is related to a variation in surface energy for different active sites on the
surface of a solid. The existence of different active sites could have an impact on the
aerosolisation performance of dry powder inhalation (DPI) formulations with lactose as a
carrier. α-Lactose monohydrate is used in such formulations to overcome the high
cohesiveness of the micronised drug. Previous work shows that there is a wide variation
in energy distribution, even for unprocessed standard lactose and that this affects the drug
fine particle fraction in an in-vitro experiment. From the above said it is obvious that the
distribution of the surface energy is highly relevant for an understanding of processing
and formulation performance. This current study, investigates the surface heterogeneity
of an untreated standard lactose, milled and recrystallised lactose in combination with
other techniques.
248
Poster Session P1
DIFFERENCES IN THE AMORPHOUS STATE IN DIFFERENTLY
PROCESSED LACTOSE POWDERS
Frank Thielmann and Daniel J. Burnett, Surface Measurement Systems,
Ltd., Allentown, PA, USA; [email protected]
137
Amorphous materials are inherently metastable and therefore tend to revert to a more
thermodynamically stable, crystalline form. As this instability has a potentially negative
impact on storage and drug potency it is important to understand the thermodynamic
properties of the amorphous phase. In recent years the main attention of research has
been focused on the amorphous content of drugs and excipients. Newer research also
suggests that even for a single compound, different amorphous states exist each with
variations in the energetic state and these various states can cause differences in product
behaviour. If, for example the same crystalline compound is made amorphous using
different techniques (e.g. by different processing procedures) a different amorphous state
possessing different thermodynamic properties can result. In this study the impact of
processing technologies on the amorphous state of lactose has been investigated. For this
purpose the same batch of alpha lactose monohydrate has been transformed into an
amorphous state using four techniques: spray-drying, freeze-drying, super-critical fluid
(SCF) freeze-drying and high energy milling. The energetic state on the surface of each
sample has been explored by Inverse Gas Chromatography (IGC) in terms of the
dispersive and specific surface energy. To make results comparable the same particle
fractions (45-63 μm) have been used. As different procedures can result in different
amorphous contents, the samples have been exposed to humidities just above the glass
transition to induce a slow crystallisation. The surface energy was monitored during the
crystallisation process. Results suggest that at higher amorphous contents the surface
energies of the same sample remain constant while at lower amorphous contents surface
energies decrease, possibly due to an increased contribution of crystalline alpha lactose
monohydrate. When samples processed using different techniques but with the same
amorphous content are compared significant differences can be found suggesting
different energetic states.
Poster Session P1
PHYSICOCHEMICAL CHARACTERIZATION OF NANOSIZE ZINC
OXIDE AND TITANIUM DIOXIDE USED AS UV SUNSCREEN
AGENTS IN COSMETIC FORMULATIONS
Ana Morfesis, Malvern Instruments Inc,MA; David Fairhurst, Dynamic
Cosmetics Inc., PA; [email protected]
138
The physical (particulate) sunscreen agents, ZnO and TiO2, are increasingly used to
provide UV protection in a wide variety of cosmetic and personal care products. The
particle size distribution (PSD) of these ZnO and TiO2 materials directly impacts product
performance in two critical ways. First is the UV attenuation efficiency, as measured by
the ratio of the measured sun protection factor (SPF) per % active. Second, cosmetically
acceptable and aesthetically pleasing products must also be transparent (i.e. nonwhitening) when applied to the skin; this is a function of the scattering efficiency for
249
visible light. All sunscreen actives are FDA monographed drugs. The grade of oxide
currently used for sunscreens differs significantly in particle size (PS) from standard USP
grade (as used in diaper rash ointments) in that it is prepared using much smaller sized
materials, typically around 100nm for ZnO and 80nm for TiO2 . However, although the
goal has been to produce new sunscreen formulations using smaller sized ZnO and TiO2
materials, the actual PSD in the final formulation is also very dependent upon the
chemical make up and processing steps that occur throughout the product’s production.
Therefore a detailed knowledge of the particulate surface chemistry and how that relates
to the other (chemical) components in the product is important. For example, the majority
of the titanium dioxide materials that are currently used in cosmetic applications have
been surface treated usually with combinations of Al2O3 and SiO2 that results in a wide
variation of surface chemistry that critically affects the dispersability of these
(hydrophilic) materials in (the predominantly hydrophobic) cosmetic vehicles. ZnO and
TiO2 each have their own chemical characteristics and these respective materials require
interfacial characterization in order to obtain maximum product performance particularly
in a formulated product, i.e. sunscreen products. All these factors will be reviewed and
illustrated by measurements comparing and contrasting both the particle size and zeta
potential of a variety of first- and (newer) second-generation nanosize, ZnO and TiO2
based sunscreen products.
Poster Session P1
PROBE-MOLECULE FTIR SPECTROSCOPY FOR SENSING ACIDBASE AND REDOX PROPERTIES OF METAL OXIDE
NANOPARTICLES IN AQUEOUS MEDIA
I.V. Chernyshova and P. Somasundaran, NSF IUCRC for Advanced Studies
in Novel Surfactants, Langmuir Center for Colloids and Surfaces, Columbia
University, New York, N.Y. 10027, USA; [email protected]
139
To adequately link acid-base and redox properties of nanoparticles (NPs) in aqueous
media to desirable transport, fate, and toxicity outcomes as well as to design NPs for a
target function, there is a need to develop accessible experimental techniques capable of
fast and non-intrusive sensing of these properties. We adapt FTIR spectroscopy for this
purpose, extending the probe-molecule method widely employed in the catalysis studies.
We propose to use FTIR spectra of adsorbed ambient CO2 and ferric/ferrous cyanide to
assess acid-base and redox properties of metal oxide NPs in aquatic media, respectively.
Using this technique, we show that decrease in nanoparticle size and synthesis-dependent
crystallinity of hematite (α-Fe2O3) results in both an increase in basicity and a decrease in
the oxidative catalytic capacity of this metal oxide. The effects are explained by the
quantum size effects, nanosize-induced changes in the structure of the NP surface and
interior, and surface delocalization of electronic charge, as well as the synthesis route
used.
250
Poster Session P1
USE OF FLUORESCENCE CORRELATION SPECTROSCOPY FOR
STUDYING POLYELECTROLYTE-NANOPARTICLE INTERACTION
Nadia J. Edwin, Chengqing Wang, Denis Pristinski and Vivek M. Prabhu,
National Institute of Standards and Technology, Gaithersburg, MD 20899,
140
Formation of polyelectrolyte complexes is very facile via layer-by-layer sequential
adsorption of oppositely charged species method. This method has been used to fabricate
versatile materials with tailored properties. However, the fundamental assembly
mechanisms of these advanced engineering materials and the adsorption kinetics of these
systems is not completely understood. We use fluorescence correlation spectroscopy
(FCS), which analyzes fluctuations in the fluorescence emission of molecular ensembles
and provides the concentration, mobility, and dynamics of fluorescently labeled
molecules, to study the interaction of polyelectrolyte-nanoparticle assembled structures to
establish what’s driving the adsorption of these systems, the dependence of molecular
weight and the effects of variations in the solution environment with pH and ionic
strength. Layer-by-layer assembly was performed on fluorescent dye-labeled spherical
nanoparticles and amine and carboxyl functionalized polyelectrolytes in aqueous
solution. Changes in the dynamics of the polyelectrolyte-nanoparticle system in response
to various salt and pH conditions will be presented.
Poster Session P1
BIONANOTECHNOLOGY AND BIOMOLECULES ON SURFACES
STUDIED BY DUAL POLARISATION INTERFOROMERY
Mark Gostock, Farfield Scientific Inc. Pittsburgh, PA 15201, USA;
[email protected]
141
Dual Polarisation Interferometry (DPI) is an analytical technique used to understand the
real-time structure and behaviour of a wide range of thin films and nanosurfaces through
quantitative measurement. DPI has been successful across a plethora of surface science
applications, including polymers, surfactants, fine chemicals and biomolecules. As an
interferometric technique, DPI has a wide dynamic range so can accommodate a broad
spectrum of solvents, such as DMSO and ethanol, and buffers and buffer additives. This
means that the DPI user can carry out experiments in the conditions of choice rather than
those dictated by the limitations of other techniques. The unique, absolute measurements
provided by DPI enables the researcher to question and understand thin films and
nanosurfaces and their interactions to an extent not previously available in a laboratorybased technique. This presentation introduces the biophysical and surface analysis
technique and discusses particular research areas as; nano-scale surface assembly,
polymer-surfactant interactions, quantification of protein interactions with liposome and
bilayer structures, biocompatibility studies, quantum dot and nanoparticle
characterisation and bionanotechnology; areas in which DPI has found particular success.
251
Poster Session P1
SUCROSE - A NEW SUB-NANOMETER SIZE STANDARD?
Mike Kaszuba*, Malcolm T. Connah*, Kohei Shiba^ and Ulf Nobbmann#,
*Malvern Instruments, Malvern, WR14 1XZ, UK. ^Sysmex Corporation,
Kobe, 6512271, Japan. #Malvern Instruments, Westborough, MA 015811042, USA; [email protected]
142
Dynamic Light Scattering (DLS) is an established metrology for the characterization of
colloids, nanoparticles, polymers and biomolecules. Typically, sub-micron sizes are
quickly and easily assessed by this technique, analyzing the intensity fluctuations of
scattered light from a sample suspension. The intensity fluctations are due to Brownian
motion of the scattering objects, and lead to a characteristic decay of the obtained
intensity autocorrelation function of the signal. Advances in electronics and optics now
allow access to faster time scales and provide higher sensitivity so that ever smaller
objects may be detected. Sucrose is ubiquitious, available in highest crystalline purity
and very soluable in water. Its molecular structure is expected to resemble a prolate
ellipsoid, with a major axis of ~1.0nm and minor axes of ~0.6nm. Sucrose solutions from
5% weight/volume to 30 % weight/volume were measured in a backscattering DLS
configuration. When the viscosity, as experienced by known standard tracer beads, is
taken into account the observed diffusion corresponds directly to the size of single
sucrose molecules. Measured diameters fall under 1.0nm and 0.7nm for intensity and
volume analysis, respectively.
Poster Session P1
EVALUATION OF AG-CORE SILICA NANOPARTICLE STABILITY
DURING THE HIGH PERFORMANCE LIQUID CHROMATOGRAPHY
DISPERSION PROCESS: SURFACE CHARGE AND SOLUTION EFFECTS
Amra Tabaković and James H. Adair, Department of Materials Science and
Engineering, The Pennsylvania State University, University Park, PA 16802 USA;
[email protected]
143
A high performance liquid chromatography (HPLC) based washing method has been
demostrated as a succesful approach for the removal of residual surfactant and the dispersion
of Ag core silica nanoparticles synthesized in a cyclohexane/Igepal/water reverse micelle
system. Further consideration of both experimental and theoretical aspects of this approach
will aid in optimizing the process to produce higher nanoparticle yields while minimizing the
residual surfactant concentrations. We evaluate the effects of the changes in stationary phase
surface charge and water-ethanol ratios in solution on the degree of stability of the
microsphere-nanoparticle system at different stages of the HPLC washing process. First,
surface charge is determined by measuring mean zeta potential values for as received
stationary phase silica microspheres, as well as for silica microspheres functionalized with 1
w/o, 5 w/o and 15 w/o of both 3-aminopropyltriethoxysilane (APTES) and
carboxyethylsilanetriol (CTES) in the pH range of interest (6-8). Shifts in isoelectric point, as
well as FTIR spectra results, confirm presence of amine and carboxy groups on the silica
microsphere surface. Second, interaction energies and agglomeration probabilities between
the nanoparticles and stationary phase silica microspheres for ethanol-water suspensions
corresponding to the steps of the HPLC washing process (5:95 water:ethanol, 30:70
252
water:ethanol and 70:30 ethanol: water) and different surface functionalizations are calculated
using STABIL©. Third, the extent of surface coverage by the nanoparticles on the stationary
phase silica microspheres is evaluated using scanning electron microscopy (SEM) for the
different stages of the washing process. The SEM images show varying degrees of surface
coverage for 5:95 water:ethanol, 30:70 water:ethanol and 70:30 ethanol: water, which
correlates to the behaviour of the stationary phase-nanoparticle system predicted by the
interaction energy and agglomeration probability calculations.
Poster Session P1
DYNAMIC LIGHT SCATTERING, ATOMIC FORCE MICROSCOPY
AND TRANSMISSION ELECTRON MICROSCOPY
CHARACTERIZATION OF POLYURETHANE NANOPARTICLES
Betina Giehl Zanetti-Ramos1, Cristian Schweitzer de Oliveira2, Maurícia
Beddin Fritzen Garcia1, Tânia Beatriz Creczynsky-Pasa1, André Avelino
Pasa2, Valdir Soldi3 and Redouane Borsali4, 1 Laboratório de Bioquímica de
Macromoléculas, Departamento de Ciências Farmacêuticas; 2 Laboratório de
Filmes Finos e Superfícies, Departamento de Física; 3 POLIMAT,
Departamento de Química; Universidade Federal de Santa Catarina, 88040900, Florianópolis, SC, Brasil; 4 CERMAV/CNRS, Grenoble, France
[email protected]
144
The development of polymeric nanoparticle technology has allowed important advances
in various industrial fields such as cosmetics, pharmacy and agrochemical. As a drug
delivery system, it is important that these polymeric nanoparticles have their surface
functionalized, which in turn, improves their physicochemical and biological properties.
Recently, we have synthesized biodegradable polyurethane nanoparticles based in a
natural triol and isophorone diisocyanate (IPDI) by miniemulsion technique. Poly
(ethylene glycol) was used as a co-monomer to obtain hydrophilic and pegylated
nanoparticles. The colloidal polymeric system was them characterized for particle size
and size distribution measurements by dynamic light scattering (DLS), and for
morphological analysis using atomic force microscopy (AFM) and transmission electron
microscopy (TEM). DLS measurements of polyurethane nanoparticles in the presence of
PEG showed a monodisperse size distribution, with a mean hydrodynamic radius in the
range of 131 nm and polydispersity index of 0.39. These results were confirmed by the
AFM images, where most of the particles were spherical, smooth and with diameter
between 200 and 250 nm. The variability on particles size observed by AFM images is
justified by polydispersity index value. Furthermore, the analysis of these images
indicates that the diameter of the nanoparticles were larger than their height, resulting in a
diameter/height ratio between 2 and 5. We speculate that the nanoparticles were solid
nano-matrix structures and the hard polyurethane walls could suffer a small deformation
when deposited on mica substrate for AFM imaging. The difference of diameter values
between DLS and AFM techniques could be explained by the presence of water in the
case of DLS experiments, inducing the swelling of the nanoparticles. TEM image
confirms that the polyurethane nanoparticles prepared with PEG were spherical and the
particle size was in agreement with the results obtained by DLS and AFM. It was
observed in the TEM image that chains of PEG (hydrophilic diol) migrated at the
particle-water interface, during the nanoparticles synthesis, forming a protecting layer
253
around the particle. The formation of this protecting layer is an important feature, since it
avoids immunoresponse and increases circulation time of the nanoparticles in the blood
stream.
Poster Session P1
PLASMONIC MAGNETIC NANOPARTICLES FOR BIMODAL
IMAGING AND PHOTONIC-BASED THERAPY OF CANCER CELLS
Yong Taik Lim, Mi Young Cho and Bong Hyun Chung, BioNanotechnology
Research Center, KRIBB, Daejeon 305-806, South Korea;
[email protected]
145
In this presentation, we describe a novel plasmonic magnetic nanostructures that
combined the magnetic character of iron oxide nanoparticles with distinct surface
plasmonic character of gold nanostructures in the near-infrared (NIR) region of spectrum,
wherein the transmission of light through biological tissues is known to be quite high. We
specially designed for hollow-type gold nanostructures that contain iron oxide
nanoparticles within their hollow interiors. We have demonstrated that the novel
plasmonic magnetic nanostructure could be used as a bimodal contrast agent for MRI and
scattering-based optical imaging. We further extended their application for selective
destruction of breast cancer cells (SKBR3) by using the NIR-based photothermal effect.
The multifunctional nanostructure developed in this research, has potential in a wider
variety of novel applications related to modulated drug delivery, combined therapy (gene
therapy and chemotherapy), and theranostic nanoplatforms. As an another perspective of
our research, we expect the novel plasmonic magnetic nanostructure to enable biologists
or medical doctors to gather diagnostic in vivo imaging data by using MRI at the
preoperative stage. In addition, the pathologists can directly analyze biopsy samples
during the operative and postoperative stages by using the strong scattering properties of
the novel nanostructure, even without any further need to prepare additional samples.
Poster Session P1
INDOCYANINE GREEN-ENCAPSULATED CALCIUM PHOSPHATE
NANOCOLLOIDS AS BIORESORBABLE NEAR-INFRARED IMAGING
AGENTS
E. I. Altinoglu*, T. Russin#, P. C. Eklund*#, and J. H. Adair*, *Department of
Materials Science and Engineering, #Department of Physics, The
Pennsylvania State University, University Park, PA 16802, USA;
[email protected]
146
The demonstrated advantages associated with early detection of diseases have initiated
much interest on molecular-specific near infrared (NIR) contrast agents for sensitive,
deep tissue diagnostic imaging. The full potential of such NIR bioimaging lies in the
ability to engineer fluorescent tracers with unique optical properties that can penetrate
early-stage lesions with a high-level of targeted specificity and maximum photostability.
Here we report the synthesis and use of 50 nm bioresorbable calcium phosphate (CP)
nanocolloids, encapsulating the NIR fluorophore Indocyanine Green (ICG), as a precise
fluorescent tracer for real-time, deep-tissue imaging. Fluorescence assessments of these
254
composite CP-dye tracers demonstrate the significant optical enhancements relative to the
free fluorophore. Emission characteristics reveal that the CP matrix shields the
encapsulated ICG from solvatochromic effects and nonspecific degradations. This
colloidal caging in turn imparts a heightened photostability appropriate for real-time
imaging applications. Experimental optical performances are also used to theoretically
model the excitation and emission processes at clinical depths of greater than 10
centimeters in breast tissue. Furthermore, we have shown that the superior in vitro
performance of these tracers is also matched by improvements in vivo. Whole animal
imaging studies with nude mice illustrated enhancements in signal intensities up to 6
hours post injection, long past typical fluorophore degradations. Signal localizations in
tumors via the enhanced permeation and retention (EPR) pathway also demonstrate the
potential for specific targetability. With superior optical properties, and promising in vivo
performances, ICG encapsulating calcium phosphate nanocolloids can impart improved
efficacy for precise, deep-tissue, diagnostic imaging.
Poster Session P1
BIOCOMPATIBLE NANOSENSOR SYSTEMS FOR MEASURING pH IN
LIVING CELLS
Piotr J. Cywinski, Tristan Doussineau, Gerhard J. Mohr, Institute of Physical
Chemistry, Friedrich-Schiller University Jena, 07743 Jena, Germany;
Christoph Biskup, Sarmiza Elena Stanca, Institute of Physiology II,
Friedrich-Schiller-University Jena, Kollegiengasse 9, 07743 Jena, Germany;
Sandor Nietzsche, Centre for Electron Microscopy, Friedrich-SchillerUniversity Jena, Ziegelmuehlenweg 1, 07743 Jena, Germany.
[email protected]
147
Poly(D,L-lactide-co-glycolide) and composite silica nanoparticles were used for the
preparation of biocompatible pH sensor systems. The nanoparticles were prepared via
precipitation and sol-gel method, respectively. Fluorescein derivatives as pH sensitive
dyes and referencing Rhodamine derivatives were used in both systems. The response of
nanosensors to pH in aqueous suspensions was investigated by steady-state fluorescence
spectroscopy while fluorescence microscopy was used for studying nanosensors in living
cells. Both systems showed strong signal changes with pH in the physiological range.
Poster Session P1
SENSITIVITY ENHANCEMENT OF SPR IMMUNOSENSOR BY
NANOPARTICLES AND A NOVEL BIOLINKER PROTEIN
Sungho Ko1, Hyo-Sop Kim2, Jae-Ho Kim2, Yong-Jin Cho1,
1
Nanobiotechnology Research Group, Korea Food Research Institute,
Seongnam, Gyeonggi-Do, 463-746, Republic of Korea; 2 Department of
Molecular Science and Technology, Ajou University, Suwon, Gyeonggi-Do,
443-749, Republic of Korea; [email protected]
148
This study describes a new way to enhance the sensitivity of SPR immunosensor by the
assembly of gold (Au) nanoparticles (AuNPs) onto a Au surface in combination with a
255
fusion protein generated by genetically fusing a gold binding protein (GBP) to protein A
(ProA) serving as the affinity site for the Fc portion of antibody. A AuNPs-modified SPR
Au chip was fabricated by directly assembling the AuNPs onto the Au surface via
aminoethanethiol, as a label-free system. Scanning electron microscope (SEM) image
revealed that most of the AuNPs was uniformly distributed over the Au surface, and their
estimated size was approximately 30 nm. Then the GBP-protein A (GBP-ProA) was selfimmobilized on the both AuNPs-assembled Au chip and bare Au chip via its GBP portion
having binding properties toward Au solid, followed by oriented immobilization of
human immunoglobulin G (hIgG) by the ProA part of GBP-ProA layer formed. SPR
analyses indicated that the AuNPs-modified gold chip covered with the GBP-ProA has
higher ability (about 40%) to capture hIgG compared to the bare Au chip identically
treated. These results that the direct assembly of AuNPs onto the Au surface could
enhance the SPR signal in biomolecular interaction event, and GBP-ProA was an useful
biolinker for simple and properly oriented immobilization of antibody on the Au surface
without requiring any surface chemical modification and cross-linking reagents, resulting
in increased SPR sensitivity.
Poster Session P1
MAGNETIC RELAXATION DIAGNOSTICS USING
SUPERPARAMAGNETIC IRON OXIDE NANOPARTICLES
Sonia Kumar, Tom Lowery, Sonia TakTak, and Kim Foster, T2 Biosystems,
Cambridge, MA 02141, USA; [email protected]
149
The use of superparamagnetic iron oxide (SPIO) nanoparticles as magnetic relaxation
switches (MRSW) serves as a powerful platform for diagnostic assays. MRSW
nanosensors function by transitioning between dispersed and aggregated states in the
presence of an analyte which corresponds to a predicted change in the spin-spin (T2)
relaxation times of the surrounding water molecules. The change in T2 enables rapid,
single-step detection of the analyte making it well suited for clinical diagnostics. An
additional attractive feature of MRSW assays is the ability to make measurements in nonoptically clear samples which minimizes sample processing. This type of assay has been
demonstrated previously with ultra-small monocrystalline SPIO (10-30nm radius) in the
detection of various analytes including enzymes, small molecules, single-stranded DNA
and viruses. Here we report the use of the SPIO with sizes ranging from 100nm-1um for
the homogeneous detection of various clinically-relevant analytes. These larger
nanoparticles have the potential to provide higher sensitivities over larger dynamic ranges
than their smaller counterparts. Aggregation or the formation of clusters is modulated
through analyte-specific antibodies conjugated to the surface of the nanoparticles. This is
either achieved via direct conjugation or using a streptavidin/biotin platform. Because
the size and proportion of clusters in solution relates to the change in signal, maximizing
these parameters can dramatically improve assay response. Clustering was enhanced by
increasing the valency of the target by promoting multiple nanoparticles binding to a
single analyte. This was achieved by targeting multiple epitopes and by introducing
secondary antibodies. Beyond cluster size, empirical testing was used to optimize assay
conditions based on nanoparticle characteristics and signal acquistion parameters. By
controlling these parameters, desired sensitivty and limits of detections for clincal
analytes such as hCG and cardiac troponin I were achieved.
256
Poster Session P1
DEXTRAN-COATED GOLD NANOPARTICLES FOR THE
ASSESSMENT OF ANTIMICROBIAL SUSCEPTIBILITY
Sudip Nath 1, ‡, Charalambos Kaittanis 1, 2, ‡, Alisa Tinkham 2, and J. Manuel
Perez 1, 2, 3A 1Nanoscience Technology Center, 2 Burnett College of
Biomedical Sciences, and 3Department of Chemistry, University of Central
Florida, 12424 Research Parkway, Suite 400, Orlando, Florida 32826, USA;
150
[email protected]
Microorganisms quickly develop and acquire resistance mechanisms to antibiotics.
Therefore, the determination of potent antibiotic or antibacterial agents and the
administration of these agents at dosages that will effectively suppress bacterial growth
(antimicrobial susceptibility) is important for clinical decision making and public
healthcare. Currently, the assessment of antimicrobial susceptibility is a day-long
process. Considering this, we have developed a nanoparticle-based antimicrobial
susceptibility assay based on the Concanavalin A-induced clustering of dextran-coated
gold nanoparticles, where the nanoparticles have the ability to assess the levels of
available complex carbohydrates in bacterial suspension. When the bacteria do not grow
in the suspension, addition of Concanavalin A results in the formation of extensive
dextran gold nanoassemblies. The induction of these large nanoassemblies is mediated by
the presence of free carbohydrates, resulting in large shifts in the surface plasmon band of
the nanoparticles. In contrast, when the bacteria grow, the levels of free carbohydrates
decrease because of the enhanced carbohydrate uptake by the proliferating bacteria. This
causes a decrease in the size of the gold nanoparticle clusters and an increase in the
population of nanoparticles that bind to bacterial surface carbohydrate-containing
epitopes, causing smaller shifts in the plasmonic band. The gold nanoparticle-based
determination of antimicrobial susceptibility provides results within 3 hours and can be
used for the high-throughput screening of samples during epidemics and identification of
new antimicrobial agents, expediting clinical decision-making.
Poster Session P1
PHOTOCROSSLINKED DEXTRAN GELS AS DRUG DELIVERY
SYSTEMS
José F. Almeida1,2, Paula Ferreira 1,3, Armando Alcobia4, António Lopes2,
Maria H. Gil1; 1- Dept. Eng. Química - FCTUC, P-3030-790 Coimbra,
Portugal; 2- Inst. Tecnol. Química e Biológica - UNL, P-2781-901 Oeiras,
Portugal; 3- Uni. Católica Port, CRB, Campus Viseu, P-3504-505 Viseu,
Portugal; 4- Hosp. Garcia Orta, P-2801-951 Almada, Portugal;
[email protected]
151
Controlled release from biocompatible materials has received recently much attention for
its biomedical applications. Due to their biocompatibility and biodegradability,
gluocopyranosides such as chitosan and dextran appears as promising polymer materials
if one is able to regulate their rheological properties and the encapsulation/release
257
efficiency. In this work we prepared graft polymer gels from dextran (Mw=5-40×106).
The starting polymers were dissolved in dimethyl sulfoxyde and an isocianate with a
vinyl group was added to the mixture in order to introduce double bounds to the
polysaccharide. Different degrees of modification were tested, between 25 and 33% of
total hydroxyl groups modified in dextran. As a copolymer we tested NIsopropylacrylamide (NIPAAm) in order to give gels thermal sensitivity, and to improve
their biocompatibility FTIR data after the modification showed a peak associated with the
presence of C=C. For the grafted Dex-NIPAAm systems, FTIR revealed the presence of
two peaks around ~1650 and ~1550 cm-1 which can be ascertained with the typical amide
I and II bands of NIPAAm, revealing the success of the grafting reaction. The model drug
we used is a potent antiemetic substance used in the prevention of chemotherapy-induced
nausea and vomiting, Ondansetron ®, which was incorporated in the gel after the
polymerization. The transition temperature was evaluated by analyzing the transmittance
of the solution at different temperatures, Swelling capacity and cycles of release of the
drug were evaluated with essays where temperature were varied in the physiological
range of interest (withdrawing of aliquots and Spectrophotometer analysis). Results
showed that, irrespective of the polymers, there is a positive correlation between
NIPAAm concentration and swelling, as well as with drug incorporation. Release essays
show an initial burst followed by slow release but no significant pH dependence (in the
range of interest) and a moderate dependence with temperature. The gels obtained
showed promising results for their application as drug delivery systems for different
purposes.
Poster Session P1
152
ADSORPTION OF LOADED LIQUID CRYSTALLINE PARTICLES AT SURFACES
Yao-Da Dong, Ian C Larson, and Ben J Boyd; Monash Institute
Pharmaceutical Science, Monash University, Parkville, Australia;
[email protected]
Self-assembled systems such as inverse cubic and hexagonal phase liquid crystals may be
dispersed to form submicron particles (eg. cubosomes and hexosomes), which retain the
internal bulk phase structure. Our previous investigation (published) indicated that, unlike
monoolein-based cubosomes, phytantriol-based cubosomes and hexosomes do not
change their lattice structure with addition of Pluronic F127 block co-polymer as
stabilizer, indicating that the block polymer is most likely adsorbed on the exterior
particle surface. Adhesion force measurements using the atomic force microscope were
used to confirm the more hydrophobic nature of phytantriol cubic phase compared to
monoolein cubic phase. Further ATR-FTIR investigation of particle adsorption showed
greater adsorption and adhesion of cubosomes onto a hydrophobic surface prepared using
phytantriol compared to those from monoolein. We hypothesized that the polymer was
only loosely surface adsorbed for phytantriol cubosomes, and set out to further
investigate differences in the adsorption of these particles onto both model and applied
surfaces, with a view to their use as agrochemical delivery agents. 1. Quartz crystal
microbalance (QCM) was used to study the adsorption of cubosomes and hexosomes
onto hydrophobic and hydrophilic surfaces. 2. Particle adsorption was evaluated directly
258
by quantifying the delivery of radiolabelled model herbicides encapsulated in cubosomes
and hexosomes onto a model leaf surface (tristearin) and real leaf surfaces after extensive
rinsing with water. 3. In a variation on 2. above, loaded cubosomes and hexosomes were
allowed to dry onto model surfaces overnight, then immersed in water to observe systemsurface interaction such as rinse resistance and detergency. Both cubosomes and
hexosomes showed greater adsorption onto hydrophobic surfaces than hydrophilic
surfaces (by QCM). Phytantriol based cubosomes showed the greatest adsorption on
hydrophobic surfaces, while phytantriol hexosomes showed the lowest adsorption, both
in agreement with the previous FTIR adsorption experiments. Phytantriol-based
cubosomes also showed the lowest susceptibility to rinse off after adsorption. In drydown experiments, reminiscent of actual ‘field’ application of agricultural emulsions, the
GMO-based systems were readily washed from the surface, but also interacted with
model wax layers, with significant disruption of model wax layer structure evident
compared to adsorbed phytantriol particles. A correlation was found between
cubosome/hexosome adsorption and both the force of interaction between the parent
liquid crystalline surface. The results indicate that careful selection of materials for
preparation of cubosomes and hexosomes may yield particles with potential application
in agricultural delivery.
Poster Session P1
AN INNOVATIVE CONCEPT OF TARGETING USING
MONONUCLEAR PHAGOCYTES AS CARRIER FOR THERAPEUTIC
NANOSYSTEMS
Pascale Valot1, Sandrine Bourgeois 1,2, Hanna Mouaziz1, Ali Boussaïd3,
Serge Nataf3, Hatem Fessi 1,2e ; 1 Université de Lyon F-69000, Lyon, France;
Université Lyon 1, LAGEP UMR-CNRS 5007, F-69622, Villeurbanne,
France ; 2 Université de Lyon F-69000, Lyon, France; Université Lyon 1,
ISPB-Faculté de Pharmacie, Laboratoire de Génie Pharmacotechnique et
Biogalénique, F-69008, Lyon, France ; 3 Université de Lyon F-69000, Lyon,
France; Université Lyon 1, INSERM U433, Faculté de médecine Laennec, F69008, Lyon, France ; [email protected];
[email protected]
153
The purpose of this work is to develop a new and original strategy of targeting using
mononuclear phagocytes (macrophages MPs or dendritic cells DCs) as carrier for
therapeutic nanoparticles (NPs) in order to struggle against Parkinson disease. Therefore,
experimental studies were investigated to optimize cellular uptake of fluorescent
nanoparticles (RedNile NPs) by the improvement of NPs formulation. At that time no
medicinal treatment had shown the efficiency on Parkinson disease progress. In this
study, the all-trans retinoic acid (atRA), an active metabolite of vitamin A, was
encapsulated into NPs. atRA exerts a stimulatory effect on macrophages. Thus, the
objective is to design an atRA delivery system for macrophages in order to maintain
macrophage stimulation. Indeed, these cells play a major role in the inhibition of
Parkinson disease evolution by producing various cytokines. RedNile (RN) or atRAloaded NPs were prepared by the nanoprecipitation method. Briefly, the polymer, poly-εcaprolactone (PCL Mw ≈ 80000) or poly-D-lactic acid (PLA Mw ≈ 20000) and RN or
atRA were dissolved in acetone. This organic solution was then poured in an aqueous
259
phase containing Montanox® VG 80 and the precipitation was formed immediately upon
mixing at room temperature. The freshly formed nanospheres (NSs) suspension was then
concentrated by low vacuum rotary evaporation for the complete elimination of the
organic solvent. To prepare nanocapsules (NCs), an organic oil (miglyol 829) was added
to the organic solution to dissolve RN or atRA. By this method, various size NPs were
prepared. Among the factors influencing NPs characteristics (size (φ) and polydispersity
index (PDI)), we focused on the influence of polymer content. The best results were
obtained for a polymer amount of 2% (φNC PCL = 504 nm, PDINC PCL = 0.168 and φNC PdLA
= 397 nm, PDI NC PdLA = 0.188). In vitro cellular uptake of NCs and NSs was conducted
using at first RN-loaded NPs dispersed in macrophages culture medium for 24H. The
success of fluorescent NPs phagocytosis by macrophages was assessed by fluorescent
and confocal microscopy. The results have shown that polymeric RN-NPs were
successfully internalized by macrophages. In a second step, the encapsulation efficiency
of atRA in both NCs and NSs was determined by HPLC (λ=356 nm). The results showed
that atRA was entrapped, in the case of NCs, at 80% by the PCL matrix and at 99% by
the PLA matrix. We have demonstrated that the potential of encapsulating atRA in NCs
was greater than in NSs, respectively equal to 70% and 25% with PCL and PLA matrix.
The present work proposed a novel strategy of cellular therapy by using biological
carriers (MPs or DCs) of atRA nanoparticulate systems. We can concluded that PCL and
PLA present advantages as a matrix material for NPs preparation well internalized by
MPs. Even if in vivo and in vitro biological process could be different, an in vitro
investigation can provide preliminary evidence to show the advantages of NPs versus free
drug. Current studies are performed to determine the in vivo efficacy of the newly
developed formulations on MPs.
Poster Session P1
EVALUATION OF NANOPARTICLES AS A VACCINE DELIVERY
SYSTEM
Aravind Chakrapani, Padma Malyala, James Chesko, Kathryn Patton,
Derek O’Hagan and Manmohan Singh. Novartis Vaccines and Diagnostics,
Emeryville, CA 94608, USA; [email protected]
154
Biodegradable nanoparticles (<200nm) made of Poly (lactide-co-glycolide), (PLG) were
synthesized based on a solvent-displacement method. The processing parameters allow
for high yield of nanoparticles and easy scale-up for commercial production. Small
molecule immune potentiators (SMIP) were encapsulated and protein-antigens were
adsorbed on the surface of the particles to facilitate the use of the nanoparticles as a novel
vaccine delivery system. High encapsulation efficiencies were attained by encapsulating
a model immunopotentiator and were analysed using an ultra performance liquid
chromatography (UPLC) assay. In vivo studies to determine the efficacy of the delivery
system were conducted and compared with more conventional formulations (MF-59).
The nanoparticle formulation was lyophilised and reconstituted to the initial size with
excipients appropriate for use in a vaccine formulation.
260
Poster Session P1
MONODISPERSED BIOCOMPATIBLE THERMALLY RESPONSIVE
NANOPARTICLE HYDROGELS
Thuy T. Chastek, Thomas Q. Chastek, Aniket Wadajkar, KyTai Nguyen,
Polymers Division, National Institute of Standards and Technology, 100
Bureau Drive Gaithersburg, MD 20899-8542, USA; [email protected]
155
Over the last decade, hydrophilic polymer gels of nanoscale size (nanogels) have been
extensively investigated due to their many potential applications including biosensors and
drug delivery systems. Their ability to swell in suitable hydrophilic solvents to trap
numerous substances inside the gel makes them attractive for use in delivery applications
such as protein and gene delivery. Particular focus has been directed toward “smart”
hydrogels which swell or shrink rapidly in response to external environmental stimuli
such as pH, temperature, ionic strength, and electro stimulus. We synthesize such
monodisperse biocompatible thermally responsive nanoparticle poly(Nisopropylacrylamide) hydrogels, and analyze their size with dynamic light scattering
(DLS) and electron microscopies. We also synthesize these monodisperse nanoparticles
within microfluidic devices having integrated measurement capabilities (on-line dynamic
light scattering) that we have developed. These nanoparticles were synthesized by
varying the concentrations of N-isopropylacrylamide monomer, biocompatible
surfactants (Pluronics L64, P65, and P85), and potassium persulfate initiator.
Monodisperse nanoparticles were obtained with optimal conditions. The surfactant and
initiator concentration significantly affect the resulting particle size. The 3-(4,5dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium,
inner salt) (MTS) colorimetric assay showed these nanoparticles are biocompatible.
Poster Session P1
FUNCTIONALIZATION OF SILICA NANOPARTICLES BY SURFACEINITIATED RAFT POLYMERIZATION AND CLICK CHEMISTRY
Yu Li and Brian C. Benicewicz, NYS Center for Polymer Synthesis,
Department of Chemistry and Chemical Biology, Rensselaer Polytechnic
Institute, Troy, NY, 12180, USA; [email protected]
156
As a versatile controlled radical polymerization technique, reversible additionfragmentation chain transfer (RAFT) polymerization has emerged as a very promising
tool in the surface modification of nanoparticles with synthetic polymers. In this work, a
functional monomer with a pendant “clickable” moiety, 6-azidohexyl methacrylate
(AHMA), was prepared which could be polymerized on the nanoparticle surfaces via
surface-initiated RAFT polymerization with considerable control over the molecular
weight and molecular weight distribution. The subsequent functionalization of PAHMA
grafted nanoparticles was successfully performed via a copper-catalyzed Huisgen dipolar
cycloaddition with phenyl acetylene with high efficiency. This strategy of combining
surface-initiated RAFT polymerization with click chemistry provides a promising way to
modify the nanoparticle surfaces with a wide range of functional polymers.
261
Poster Session P1
PREPARATION OF SURFACE MODIFIERS FOR MULTI-WALLED
CARBON NANOTUBES THROUGH NITROXIDE MEDIATED
POLYMERIZATION TECHNIQUE AND THEIR APPLICATION FOR
THE FABRICATION OF COUNTER ELECTRODES FOR DYESENSITIZED SOLAR CELLS
Hee Jung Choi and Sung Chul Hong*, Department of Nano Science and
Technology, Sejong University, Seoul 143-747, South Korea;
157
In this presentation, the preparation of well-defined polymeric surface modifiers for
multi-walled carbon nanotubes (MWCNT) through nitroxide mediated polymerization
(NMP) technique and the fabrication of counter electrodes for dye–sensitized solar cell
(DSSC) using the modified MWCNT are reported. Poly(maleic anhydride-co-pacetoxystyrene)-block-poly(p-acetoxystyrene)s were synthesized, followed by a
functionalization with pyrene through imidization reaction. P-acetoxystyrene repeating
units were then converted into p-hydroxystyrene repeating unit through hydrolysis
reaction for the preparation of MWCNT paste. The structural and thermal properties of
the copolymers were characterized by using gel permeation chromatography (GPC), gas
chromatography (GC), proton nuclear magnetic resonance spectroscopy (1H-NMR),
fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA).
The surfaces of MWCNTs were modified through “polymer-wrapping” technique using
the copolymers and the dispersibilities of the modified MWCNTs in various solvents
were examined. Counter electrodes in dye-sensitized solar cells were also fabricated
using the modified MWCNTs and their properties were investigated.
Poster Session P1
SYNTHESIS AND SURFACE MODIFICATION OF CITRATEPROTECTED GOLD NANOPARTICLES FOR BIOMOLECULAR
DETECTION
Qiu Dai, Xiong Liu and Qun Huo, Nanoscience Technology Center,
Department of Chemistry, University of Central Florida, Orlando FL 32826;
158
Citrate-protected gold nanoparticles with a diameter of 30 nm have many unique
properties such as large optical absorption and light scattering cross section, surfaceenhanced Raman scattering that make them very promising optical probe materials for
biomolecular imaging and detection. However, there are many remaining problems and
challenges that prevent the extensive applications of gold nanoparticles in bioconjugation
chemistry. The surface chemistry of the nanoparticles plays a critical role in retaining the
biological function of the biomolecules conjugated to nanoparticles. Currently available
synthetic methodologies, however, are not satisfactory at providing gold nanoparticles
with appropriate surface chemistry for biological applications. Through our study, we
have explored a number of methods to increase the water solubility, biocompatibility and
biostability of gold nanoparticles. We conducted bioconjugation study of the surface-
262
modified gold nanoparticles with different antibodies and DNA probes. The applications
of these bioconjugated gold nanoparticles for cancer biomarker and oligonucleotides
detection will be presented in this conference.
Poster Session P1
PREPARATION OF POLYSTYRENE BASED FUNCTIONAL BLOCK
COPOLYMERS THROUGH NITROXIDE MEDIATED
POLYMERIZATION TECHNIQUE AND THEIR APPLICATIONS AS
SURFACE MODIFIERS FOR NANOPARTICLES AND NANOTUBES
Sung Chul Hong, Department of Nano Science and Technology, Sejong
University, Seoul 143-747, South Korea; [email protected]
159
Polymer nano-composites have been studied as functional materials for many cuttingedge applications owing to the combination of good processibility of polymer and high
functionality of nano-particles and nano-tubes. Generally, the surface modifications of
the nano-objects are required to ascertain a good dispersion of the objects in solvents and
polymer matrices. Well-defined block copolymers having controlled number of
functional groups can be used as surface modifiers for these purposes, where the block
copolymers can be prepared through controlled polymerization techniques. In this
presentation, various polystyrene based functional block copolymers were prepared
through living radical polymerization technique, especially nitroxide mediated
polymerization technique. The surfaces modifications of various nano-objects were
demonstrated with the block copolymers, which resulted in improved dispersion of the
nano-objects and better nano-composite properties.
Poster Session P1
A FACILE APPRPOACH TO GRAFT POLY (3,4PROPYLENEDIOXYTHIOPHENE) ON MULTIWALLED CARBON
NANOTUBES
Nanjundan Ashok Kumar, Sung Hoon Kim, Yeon Tae Jeong*, Division of
Image and Information Engineering, Pukyong National University, Busan
608-739, Republic of Korea; [email protected]; [email protected]
160
Functionalisation of carbon nanotubes (CNTs) is a key step for the integration of new
materials into different systems for most of the technological applications. There are a
number of polymers having much importance and playing a key role in wide variety of
material science applications ranging from semiconductor to nanobiotechnology. Among
them, poly(3,4-propylenedioxythiophene) (PProDOT), is one of the well known
conjugated polymer having applications in semiconductor engineering and molecular
electronics. In this study we describe a straight forward strategy to graft PProDOT onto
functionalized nanotube (f-MWNT) surfaces. The chlorinated MWNTs (MWNT-COCl)
were reacted with 3,4-propylenedioxythiophene (ProDOT-OH) followed by oxidative
polymerization to prepare the PProDOT-g-MWNT hybrid. FTIR spectroscopy was
employed to characterize the change in surface functionalities which revealed that the
PProDOT was covalently grafted to the MWNTs while TGA was used to study the
263
weight gain due to the functionalization. The morphology micrographs of the grafted
PProDOT on MWNTs as evidenced by FESEM and TEM showed apparent effect on the
structure and appearance of the MWNTs by growing thicker as expected from surface
modification. Our experimental results show that a decent degree of the polymer has been
functionalized to the tubes and the complex exhibited improved thermal stability. The
technological implication of this approach is that any suitable polymer could be
fabricated by this versatile process. Due to the wide role and importance of PProDOT in
electrochromic devices, these hybrids are expected to have practical and great potential
applications for high performance devices.
Poster Session P1
ADHESION AND PARTICLE DEFORMATION OF SUBMICRON-SIZED
LATEX PARTICLES ON HYDROPHOBICALLY-MODIFIED SOLID
SUBSTRATES AT ROOM TEMPERATURE
Jung Min Lee1, In Woo Cheong2, and Jung Hyun Kim1; 1Department of
Chemical Engineering, Yonsei University, 134 Shinchon-dong, Sudaemoonku, Seoul 120-749, Republic of Korea ; [email protected];
[email protected]; 2Department of Applied Chemistry, School of
Engineering, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu,
Daegu 702-701, Republic of Korea.
161
Two- and three-dimensional colloid arrays were fabricated using three different kinds of
monodisperse poly(styrene/sodium p-styrene sulfonate) (poly(St/NaSS) (i.e., high- and
low-charged uncrosslinked, and low-charged crosslinked poly(St/NaSS) particles) on 3aminopropyl trimethoxysilane (APTMS)-modified glass substrates at 20 °C. The array
patterns were investigated by field-emission scanning electron microscopy (SEM),
atomic force microscopy (AFM), and UV-visible spectroscopic analyses. The adhesive
force measured by AFM analysis revealed negligible attractive force between APTMS
and the poly(St/NaSS) particles. The adhesion force measured between a 3-aminopropyl
trimethoxysilane (APTMS)-modified SiNx tip and the self-assembled particle arrays was
in good agreement with the attractive force calculated using the Lifshitz theory with the
appropriate Hamaker constants. The crosslinked poly(St/NaSS) particles on the APTMSmodified glass substrate showed mainly hexagonal and square lattice-free patterns
without any crevices, in stark contrast to that of the cleaned, bare glass substrate. The
APTMS layer provided the necessary ‘free-slipping’ condition in which nuclei of
scattered pinnings of particles in the colloidal crystal were absent. As a consequence,
dense fcc (or hcp) packing densities (high-charged uncrosslinked: 0.80, low-charged
uncrosslinked: 0.76, and low-charged crosslinked : 0.76) and narrower stop bands were
obtained.
Poster Session P1
FUNCTIONALIZATION OF SILICA NANOPARTICLES BY SURFACEINITIATED RAFT POLYMERIZATION AND CLICK CHEMISTRY
Yu Li and Brian C. Benicewicz, NYS Center for Polymer Synthesis,
162
264
Department of Chemistry and Chemical Biology, Rensselaer Polytechnic
Institute, Troy, NY, 12180, USA; [email protected]
As a versatile controlled radical polymerization technique, reversible additionfragmentation chain transfer (RAFT) polymerization has emerged as a very promising
tool in the surface modification of nanoparticles with synthetic polymers. In this work, a
functional monomer with a pendant “clickable” moiety, 6-azidohexyl methacrylate
(AHMA), was prepared which could be polymerized on the nanoparticle surfaces via
surface-initiated RAFT polymerization with considerable control over the molecular
weight and molecular weight distribution. The subsequent functionalization of PAHMA
grafted nanoparticles was successfully performed via a copper-catalyzed Huisgen dipolar
cycloaddition with phenyl acetylene with high efficiency. This strategy of combining
surface-initiated RAFT polymerization with click chemistry provides a promising way to
modify the nanoparticle surfaces with a wide range of functional polymers.
Poster Session P1
SILICA NANOPARTICLES FUNCTIONALIZED WITH
ORGANOSILANES FOR IMMOBILIZATION OF CHIRAL Mn(III) SALEN
COMPLEXES
Clara Pereira and Cristina Freire; REQUIMTE, Departamento de Química,
Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169007 Porto, PORTUGAL; [email protected]
163
Silica nanoparticles present an enormous potential in numerous areas including sensors,
protein, enzyme and drug delivery systems, catalysis, composite materials and for
separation and medical diagnostics. In the field of catalysis, the immobilization of
transition metal complexes onto solid supports is a theme of significant importance
towards the goals of Green Chemistry, leading to several advantages namely the
heterogeneous catalyst easy separation from the reaction media and its reusability. In this
context, silica nanoparticles are promising materials for the development of
heterogeneous catalysts, being expected improved properties when compared with the
bulk counterparts related with their nanometer size. Due to the presence of silanol groups
onto silica nanoparticles surfaces, they can be easily modified with bifunctional
molecules (spacers), thus offering the possibility of adding new functionalities onto the
nanoparticles surface. The catalytic epoxidation of olefins is a subject of great relevance
since epoxides are important and versatile synthetic intermediates for the chemical
industry. Chiral manganese(III) salen complexes, namely Jacobsen-type catalysts, have
been reported has highly efficient homogeneous catalysts in the epoxidation of olefins.
Jacobsen-type chiral catalysts have already been immobilized onto organic polymers,
activated carbons, zeolites, mesoporous silicas, clays and pillared clays, for subsequent
application in catalysis. In this work, commercial silica nanoparticles were
functionalized with diferent organosilanes. These modified materials were used as
supports to immobilize chiral Jacobsen–type complexes. All the materials were
characterized by several techniques, namely Fourier transform infrared spectroscopy
(FTIR), X-Ray photoelectron spectroscopy (XPS), elemental analyses, scanning electron
microscopy (SEM) and solid state nuclear magnetic resonance (13C and 29Si NMR), to
265
gather information about the success of the functionalization and complex immobilization
procedures. These new manganese based materials will be subsequently applied as
heterogeneous catalysts in the asymmetric epoxidation of olefins.
Poster Session P1
DYNAMIC LIGHT SCATTERING STUDY OF PROPARGYL
ACRYLATE PARTICLES MODIFIED WITH POLY(ETHYLENE
GLYCOL)
Parul Rungta, Volodymyr Tsyalkovsky, Ryan Roeder, David D. Evanoff and
Stephen H. Foulger, School of Materials Science and Engineering, Center for
Optical Materials Science and Engineering Technologies (COMSET),
Advanced Materials Research Laboratories, 91 Technology Drive, Anderson,
SC 29625, USA; [email protected]
164
The copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition between azides and terminal
alkynes to form 1,2,3-triazoles, often referred to as a variant of “click” chemistry, has
found a wide range of applications in varied synthetic and/or functionalization of
molecules, surfaces, and particles. The use of the azide and alkyne moieties as chemical
handles allows for the attachment of dissimilar systems through a stable triazole ring.
This implementation of click chemistry exploited in the current effort focuses on azideterminated polymer chains attached to 100 nm poly(propargyl acrylate) (PA) particles.
Specifically, poly(ethylene glycol) (PEG) polymer chains of different number average
molecular weights ranging from 1K to 10K were modified with terminal azide groups.
Dynamic light scattering was used to characterize the hydrodynamic diameters of the
surface modified PA particles and the increase in diameter was correlated to the
molecular weights of the PEG chains. In addition, Fourier transform infrared
spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) were done to ensure
the formation of the triazole ring.
Poster Session P2
NANOPARTICLES OF HIGH DIELECTRIC MATERIALS AS
INNOVATIVE COATING OF CARBON NANOTUBES
Emanuela Tamburri, Francesco Toschi, Silvia Orlanducci, Valeria
Guglielmotti, Vito Sessa, Maria Letizia Terranova, Università di Roma “Tor
Vergata”, Dip.to Scienze e Tecnologie Chimiche and MINASlab, Via della
Ricerca Scientifica, Roma, 00133, Italy; [email protected];
Marco Rossi, Università di Roma “Sapienza”, Dip.to di Energetica, Via
Scarpa, Roma, 00100, Italy
269
Carbon nanotubes coated with functional nanoparticles are excellent candidates as
starting blocks for electronic, mechanical and optical systems. The heterojunctions
formed at carbon nanotubes coated with dielectrics could have applications in memory
device for storing electrical charge, and generally for all electronic devices moreover
nanometric coating with metals oxide could be used in catalytic systems and sensors.
However their use requires better knowledge in term of synthesis process and thus
materials properties. Arrays of single walled carbon nanotubes (SWNTs) have been
266
successfully coated by crystalline high dielectric materials in form of nanoparticles
directly grown during the synthetic process. The investigated dielectrics were: diamond,
titania TiO2, tantalium pentoxide Ta2O5. The SWNTs are generated using a hot filament
Chemical Vapour Deposition apparatus by reaction between carbon nanopowders and
atomic hydrogen in presence of a metal catalyst ( Fe or Ni). The versatility of apparatus
allow to obtain SWNTs arrays differently oriented and aligned to respect the substrate
and growth on selected area of the substrate. After the step of SWNTs incubation (few
minutes of growth), different methodologies are employed in order to deposit on the
nanotubes arrays the different nanoparticles. In particular for diamond coating we use a
higher atomic H concentration, for Ta2O5 we use a Ta filament in less reducing
environment and for TiO2 we use a Ti organo-metallic complex in form of nanometric
powder. In all cases the total time process (SWNT growth and coating by nanoparticles)
is about 10-15 minutes and the nanotubes arrays maintain their morphology. The
obtained samples are morphologically and structurally characterized by means of SEM,
Raman spectroscopy, Electron and X-Ray diffraction. The coated arrays were used as
cathode in field emission experiment. I/E curves, test of reproducibility and current
stability will be presented and discussed.
Poster Session P2
SELF-CLEANING SURFACES BY THE USE OF SILICA
NANOPARTICLES
Doris M. Spori1, S. Zürcher1,3, A. Mühlebach,2 and N.D. Spencer1,
Laboratory for Surface Science and Technology, 1ETH Zurich, Switzerland;
[email protected]; 2Ciba Speciality Chemicals, Switzerland; 3SuSoS
AG, Switzerland
270
Since the discovery of the self-cleaning properties of the lotus leaves, much effort has
been put in determining the governing parameters of such superhydrophobic surfaces.
The superhydrophobic state is (also called Cassie-state) is defined by a very high water
contact angle (above 150°) and a very low roll-off angle (below 10°). These values are
achieved due to a substantial amount of air enclosed underneath the drop. As it was seen
in recent literature, surfaces with undercut topographies support drops in the Cassie-state
even when they are slightly hydrophilic. Spherical particles and especially raspberry-like
particles (particles where smaller silica particles are bound onto larger ones) also exhibit
undercut features. Additionally, silica particles can potentially be used in many different
applications, leading to low-cost and mechanically stable surfaces. In this work the
applicability of particles, especially raspberry-like particles are tested in regard to contact
angles and soil resistance. Different morphologies are tested in order to gain a better
insight into the parameter range for the production of superhydrophobic surfaces by the
use of particles. The parameters examined are substrate- and particle functionalization,
particle size (73, 300, 500 and 2560 nm) and the choice of solvent (water, waterglycerol). If particles are dispersed in pure water, capillary forces act on wet particles on
a surface during drying. This causes the particles to assemble, group together or form
“particle chains”. By mixing the water with glycerol the so-called Marangoni-flux is
induced, which drags the particles to the middle of a drying drop and helps to assemble
the particles effectively. By testing the effect of the resulting patterns on contact angle
267
and dirt resistance, the surfaces’ sensitivity towards these effects are quantified. In a
second step an additional layer of smaller particles is applied. Optimum coverage is
evaluated by gradually dipping a positively charged, particle-covered substrate into a
solution of negatively charged nanoparticles. Hydrophobicity is achieved by
functionalizing the surface with octadecyltrichlorosilane.
Poster Session P2
ON MAGNETIC NANOPARTICLES IN A COLLOIDAL FLUID
Saurabh Sharma*, Gautam Mukhopadhyay*, Pagati Mukhopadhyay**
*Department of Physics and **CRNTS, Indian Institute of TechnologyBombay, Mumbai, 400076, India; [email protected];
[email protected]
271
In an external magnetic field, magnetic nanoparticles suspended in a colloidal fluid are
expected to line up along a chain. The effective force, called chain force, between the
particles in a chain can be treated in terms of dipole dipole interaction, when thermal
fluctuations are insignificant. However, the study of the variation of the chain-force with
the interparticle separation and particle volume has been confined only to spherical
particles. We present here the dependence of the chain-force on the shape of the
suspended magnetic nanoparticles of general ellipsoidal shape. This requires a knowledge
of the induced dipole moment of the ellipsoidal magnetic paricles which we have derived
through the concept of magnetic potential. For convenience we shall present a
comparison of the chain force for a ellipsoidal particle with that for sphere of identical
volume, as function of the interparticle separation.
Poster Session P2
SELF-ASSEMBLY OF POLYMER MICROSPHERES FOR THE
PREPARATION OF 3D OPTICAL PHASE GRATINGS
Juergen Wagner, Bernd-Reiner Paulke, and Eckhard Goernitz, Fraunhofer
Institute for Applied Polymer Research, Geiselbergstr. 69, D-14476 PotsdamGolm, Germany; [email protected]
272
Self-assembly of monodisperse microspheres into 2D or 3D ordered array structures has
attracted a lot of attention due to simplicity, flexibility, and low costs. Simple
preparation methods based on hydrodynamic flow in confined space, vertical deposition
or dipping/withdrawing can be used to crystallize highly ordered array structures which
are of particular interest as model systems for the design and fabrication of photonic
crystals and the development of new sensor concepts based on 3D optical gratings.
Moreover, these colloidal crystal templates can be inverted and infiltrated with a variety
of ferroelectric, nonlinear, photorefractive and other materials, thus permitting the
creation of new composites for optoelectronic applications. As lattice constants can be
easily adjusted by the particle diameter the photonic properties of such 3D arrays can be
customized over the whole spectral region (UV-IR). In this contribution we focus on
self-assembly of “large” monodisperse latex particles in the size range of 1.0 – 8.0 µm
into 2D and 3D ordered structures. For this purpose, well-known deposition techniques
268
were modified in order to minimize particle sedimentation during deposition. Further
modification of the arrays was achieved by infiltration with liquids or UV-curing
polymers in order to adjust the refractive index contrast. Well-ordered arrays up to 2 cm2
were organized with a thickness of 1 (monolayer) to approx. 50 layers and found to
consist of monocrystalline domains up to 104 µm2 in size. These domains exhibit
preferably stackings of hexagonally close packed particle layers resulting in ffc, hcp and
rhcp crystal structures. Optical properties and the crystalline structure of the 3D arrays
were studied by angle dependent transmission and reflectance vis-NIR-IR spectroscopy,
laser beam diffraction and spectral goniometry. Additionally, optical microscopy
equipped with a Bertrand lens was shown to be a powerful method for the study of single
crystalline domains in the case of large particles (diameter > 1 µm), where higher
diffraction orders fall in the range of the microscope objective aperture. Combination
with white light illumination and imaging by a colour CCD camera results in a
trichromatic diffraction image containing the full information of the 3D grating. RGB
pixel values can be read out directly and grating parameters can be calculated from radial
intensity maxima after calibration of the microscope/camera system. A spectral and
spatial redistribution of light in the diffraction patterns was observed depending on the
number of layers and the type of layer stacking in the arrays. This effect has potential to
design new optical RGB colour sensors based on diffractive 3D phase gratings for shape,
texture and colour recognition in image pre-processing. As an additional feature of light
diffraction on particle arrays we also present results of Talbot self imaging and fractional
Talbot pattern in the optical “near” field behind particle layers. These studies are of
special interest for potential sensor applications based on direct coupling between an
array and a CCD matrix. (We thank the German Federal Ministry for Education and Research for
financial support.)
Poster Session P2
ORGANIC-INORGANIC NANOCOMPOSITES FOR VOLUME
HOLOGRAPHIC ELEMENTS
Oksana V. Sakhno1, Joachim Stumpe1, Leonid M. Goldenberg1, Eckhard
Goernitz1 and Tatiana N. Smirnova2; 1Fraunhofer Institute for Applied
Polymer Research, Geiselbergstr. 69, 14476 Potsdam, Germany;
[email protected]; [email protected];
2
Institute of Physics, NAS of Ukraine, Kiev, Ukraine
273
Organic-inorganic composites containing inorganic nanoparticles (NP) embedded in
easily-processable organic matrices are attractive for the creation of novel components
for optical and photonic applications. The use of the NP of different functionality (e.g.
high or low refractive index, photoluminescence, non-linear optical properties, magnetic
properties) in combination with holographic patterning is promising for a variety of
multifunctional passive and active optical components and devices. The results to the
development and the investigation of several organic-inorganic composite materials
suitable for the fabrication of high-refractive index-contrast (RI) holographic volume
optical elements using the photopolymerisation in the interference pattern are presented.
The specific surface-modification of inorganic particles is a cruical point for the
preparation of the transparent materials suitable for optical application. The modification
269
of surface by organic ligands allows to introduce different NP with a maximal loading up
to 30wt.% into photosensitive acrylate mixture. Different inorganic NP such as TiO2,
ZrO2, LaPO4:Ce3+,Te3+ with the size 3-14 nm, having refractive index ranging from 1.8 to
2.5 and different organic shells were investigated. High-efficient low-scattering
transmission volume diffraction gratings with the periods 0.5-2 μm have been recorded as
result of short-time exposure (at 365 and 488 nm). of the nanocomposites to the
-2
interference pattern. RI modulation contrast up to 1.65*10 was obtained using 26wt.%
TiO2 NPs in the polymer. The influence of the NP concentration and the holographic
patterning parameters (intensity, spatial period) on the RI contrast has been investigated.
It was evident that the photo-induced diffusion of the NP between the regions of the film
corresponding to bright and dark areas of the interference pattern is responsible for the
polymer-NPs grating formation. 2D volume structures recorded by three laser beams
were also fabricated in ZrO2 containing composite. Using the photoluminescent
LaPO4:Ce3+,Te3+ NP, volume transmission hologram with diffraction efficiency up to
80% and simultenuosly performing a local light-emission in the grating planes
(submicrometer scale) enriched by the NP under UV-exitation were also developed.
Poster Session P2
ONE-POT SYNTHESIS OF TITANIA BASED SULFONATED
POLYANILINE NANOCOMPOSITES BY UV-CURING
Mohammad Rezaul Karim, Hyun Woo Lee, Mi Hwa Hwang, Jae Hyeung
Park, Hyun Mi Ji, and Jeong Hyun Yeum, Department of Advanced Organic
Materials Science & Engineering, Kyungpook National University, Daegu
702-701, Korea; [email protected]; [email protected]
274
Electrically π-conjugated polymer and inorganic hybrid composites possess interesting
optoelectronic and physiochemical properties that are attractive for their potential uses in
the fields of light emitting diodes, photovoltaic, aircraft, aero spaces, drug delivery, and
electro chromic devices. Moreover, combining two different materials e.g. electrically
conducting polymers with host filler like titanium dioxide would lead to synergic effects
in properties and provide the great benefit for the development of any new technological
applications. In this work, composites of sulfonated polyaniline-titanium dioxide (SPAniTiO2) hybrid composites have been synthesized by using a new strategy in one-pot system
of UV-cured polymerization method. Aqueous solution of aniline and orthoanilinic acid
comonomers, a free-radical oxidant and titania precursor were irradiated by UV rays.
Hydrolysis and reprecipitation of the titania precursor in aqueous aniline and orthoanilic
acid lead to the formation of titanium dioxide particles which in turn catalyze oxidation of
comonomers to sulfonated polyaniline. The resultant SPAni-TiO2 composites were
characterized by using different spectroscopy analyses like X-ray diffraction, UV-visible
and infrared spectroscopy. The UV-vis absorption bands revealed that SPAni-TiO2
nanocomposites are optically active and the blue-shifted peaks due to the presence of
titania within the SPAni matrix. Scanning electron microscopy and transmission electron
microscopy of the nanocomposite showed a uniform size distribution with spherical and
granular morphology. Thermogravimetric analysis revealed that the SPAni-TiO2
composites have a good thermal stability than the pristine SPAni.
270
Poster Session P2
UV-CURING SYNTHESIS OF WATER SOLUBLE SULFONATED
POLYANILINE-SILVER NANOCOMPOSITES BY IN-SITU
REDUCTION
Mohammad Rezaul Karim, Hyun Woo Lee, Mi Hwa Hwang, Jae Hyeung
Park, Hyun Mi Ji, and Jeong Hyun Yeum, Department of Advanced Organic
Materials Science & Engineering, Kyungpook National University, Daegu
702-701, Korea; [email protected]; [email protected]
275
Electrically conducting polymer/inorganic hybrid nanoparticles with different
combinations of two components have attracted more and more attention, since they have
interesting physical properties and potential applications. Conducting
polyaniline/inorganic silver (PAni-Ag) composites combine the merits of polyaniline and
metallic silver particles and have potential applications in catalysis, conductive inks,
thick film pastes and adhesives for various electronic components as well as have added
attraction in photonics and photography industry. The applications of PAni based
inorganic particles remain quite below the expected target due to the rigidity of PAni
backbone, causing insolubility in common solvents and infusibility at traditional meltprocessing temperatures.We have synthesized successfully water soluble sulfonated
polyaniline-silver (SPAni-Ag) hybrid nanocomposites by the in-situ reduction of UVcured polymerization method without using any reducing and/or binding agents. Aqueous
solution of aniline and orthoanilinic acid comonomers, a free-radical oxidant and silver
metal salts were irradiated by UV rays. Reduction of the silver salts in aqueous aniline
and orthoanilinic acid leads to the formation of silver particles which in turn catalyze
oxidation of comonomers to sulfonated polyaniline. The resultant SPAni-Ag
nanocomposites were characterized by using different spectroscopy analyses like UVvisible, X-ray diffraction and infrared spectroscopy. The optical absorption bands
revealed optically active and the blue-shifted peaks due to the presence of metallic silver
within the SPAni matrix. XRD patterns indicated both the broad amorphous polymeric
and sharp metallic peaks. Scanning electron microscopy and transmission electron
microscopy of the nanocomposites showed a uniform size distribution with spherical and
granular morphology. Thermogravimetric analysis revealed that the nanocomposites had
a good thermal stability than the bulk SPAni.
Poster Session P2
UV CROSS-LINKED POLY(4-VINYLPYRIDINE) POLYMER SURFACES
AS TEMPLATES FOR THE PREPARATION OF BI-MODAL GOLD
NANOPARTICLES
Min Sung Kim, Young Hwan Park, Yeon Tae Jeong*; Division of Image and
Information Engineering, Pukyong National University, Busan 608-739,
Republic of Korea; [email protected]; [email protected]
276
271
Metal nanoparticles have attracted immense interest owing to its high and specific impact
in the fields of biotechnology and bioscience. Being a noble metal, gold is widely
investigated due to its unusual properties different from those of bulk states and its
potential applications in optics, electronics, magnetic, catalysts and chemical and
biochemical sensing technologies. A variety of polymer molecules have been selected to
decorate the surface of nanoparticles for a number of purposes. Polymers can be coated
on a wide range of substrates and with different topographies under mild conditions.
Here, we report the novel and easy use of UV cross-linked poly(4-vinylpyridine) (P4VP)
thin films for the preparation of chemically bonded, different sized gold nanoparticles
(AuNPs). In this method, cross-linked P4VP thin films were provided by spin-coating
P4VP solution in butanol onto cleaned silicon wafers. These films were then
photocrosslinked via exposure to low pressure Hg lamp. The resulting films are stable
upon thorough rinsing with various solvents. Initially, ~70 nm sized AuNPs were
synthesized using a published protocol and were deposited via electrostatic adsorption on
the cross-linked P4VP films. These surfaces were further modified with 1,6-hexanedithiol
in order to functionalize the adsorbed AuNPs for the chemical immobilization of different
sized, discrete AuNPs (~20 nm). The self-assembly of 1,6-hexanedithiol on the
immobilized AuNPs and the bi-modal architectures were investigated by AFM, FESEM,
TEM, XPS, and UV-Vis spectroscopy.
Poster Session P2
EFFECT OF PARTICLE SURFACE AREA ON PROPERTIES OF
HYDROXYAPATITE NANOCOMPOSITES
Jasmeet Kaur and Meisha L. Shofner, School of Polymer, Textile and Fiber
Engineering, Georgia Institute of Technology, Atlanta, GA-30332-0295,
277
Hybrid inorganic/organic materials containing nanoscale inorganic particles may be
considered three phase materials where the nanoparticles, the polymer matrix, and the
interphase material each contribute to the resulting properties of the nanocomposite. In
order to study the individual contributions of each phase, different nanoparticles loadings
are used so that the reinforcement by isolated, mechanically percolated, and
geometrically percolated nanoparticles may be measured. This research uses a model
system comprised of hydroxyapatite (HAp) nanoparticles and a biodegradable
polycaprolactone (PCL) matrix to elucidate the contribution of each phase to the
composite’s properties. Hydroxyapatite (HAp) nanoparticles of different surface areas
will be produced, enabling nanoparticle concentration and nanoparticle surface area to be
explicitly studied with regard to interphase structure in the composite. The different
surface areas are obtained using microemulsion technique by varying the ratio of aqueous
to organic phase in the reverse micellar surfactant system. Following a calcination step,
the nanoparticles are characterized by BET, X-ray diffraction, FTIR and transmission
electron microscopy for the surface area, crystallinity, surface chemistry and morphology
respectively. Composite processing is accomplished via a solution processing route and
films are produced by solvent casting. Thermal and viscoelastic properties are measured
for the composite films.
272
Poster Session P2
SYNTHESIS AND CHARACTERIZATION OF ZnO-NANOPARTICLES
AND ZnO-POLYMER NANOCOMPOSITES
Andreas Pein, Gabriele Kremser and Gregor Trimmel, Institute for
Chemistry and Technology of Organic Materials, Graz University of
Technology, Graz, 8010, Austria; [email protected]
278
Semiconducting nanoparticles attained considerable interest in the scientific community
due to their tunable optical and optoelectronic properties. In combination with
electractive organic materials applications in the field of photovoltaics are expected. In
this contribution we present the synthesis of ZnO nanoparticles and the preparation of
ZnO/polymer nanocomposites. The ZnO particles were prepared from zinc acetat
dihydrate and potassium hydroxide in methanol as solvent.Methanol has the advantage of
high polarity so that no additional capping agents are needed to stabilize the particles.
The obtained nanocrystals were characterized by dynamic light scattering (DLS), X-ray
diffraction, UV-vis and photoluminescence spectrocopy. The used polymers comprise
end group functionalized thiophene-oligomers prepared by Suzuki cross coupling
reaction as well as asymmetrically substituted polythiophenes, prepared by a modified
Grignard metathesis reaction. As functional groups carboxylic acid groups and hydroxy
groups were introduced These new compounds were analyzed by nuclear magnetic
resonance (NMR)-, and fourier transform infrared (FTIR) spectroscopy, thermal analysis
as well as matrix assisted laser desorption ionization-time of flight mass spectrometry
(MALDI-TOF MS). The interactions of the ZnO particles with the oligo- and
polythiophenes were investigated by DLS and optical spectroscopy in solution and in the
solid phase. DLS measurements were performed to study the aggregation behaviour of
the prepared mixtures. The differences of the optical properties of the pure materials and
the mixtures are discussed in detail.
Poster Session P2
HIGH EFFICIENCY PHOTOLUMINESCENCE FROM SILICA-COATED
CdSe QUANTUM DOTS
Lei Qian, Debasis Bera, Paul H. Holloway; Department of Materials Science
and Engineering, University of Florida, Gainesville, Florida 32611 USA;
279
Recently, monodisperse semiconductor quantum dots have been utilized in an extensive
variety of applications for optoelectronics, biological labeling and bio-imaging. The
quantum yield (QY) of CdSe quantum dots capped with an organic surfactant is low at
~10%. In this study of silica-coated CdSe quantum dots, much higher QYs of ~68-82%
were demonstrated. The increased QYs for CdSe/SiO2 core/shell quantum dots are
attributed to nuetralization of charge trapped in surface states. In addition to higher
efficiency, CdSe/SiO2 core/shell quantum dots are expected to be less toxic than the
unpassivated CdSe core. The possibilities that this method for synthesizing highly
efficient luminescent quantum dots may enable additional applications in biological
labeling and down-conversion for solid state lighting will be discussed.
273
Poster Session P2
STUDY OF INDUCED AGGREGATION OF GOLD NANOPARTICLES
CAPPED BY PEPTIDES. THE DESTABILIZING ROLE OF THE
STABILIZER
Isaac Ojea Jiménez*, Marc Ramis Castelltort# and Victor F. Puntes*;
*
Institut Català de Nanotecnologia, Campus UAB, building Q, 2nd floor,
08193, Bellaterra, Barcelona,SPAIN, [email protected]; #Endor
Nanotechnologies, Campus UAB, building Q, 3rd floor, 08193, Bellaterra,
Barcelona, SPAIN
280
Recent developments in material physics and chemistry have allowed the optical,
magnetic and electrical detection of different states of biological systems and living
organism using nanomaterials, where the characteristic biokinetic behaviour of NPs is an
attractive quality for applications in diagnosis and therapy (e.g. fluorescent labeling of
cellular compartments, use of fluorescent or magnetic particles as contrast agents,
magnetic separation or target drug delivery). NPs also serve as tools to investigate and
understand molecular processes in living cells. Furthermore, NPs conjugated to
biomolecules (like elastin, antisenses, biotin-avidin, antigen-antibodies, peptides,
proteins, etc) are of great interest for both, biological diagnostics, where the NPs can
provide unique detection signatures, and for nanotechnology, where the information
content of the biomolecule can be harnessed for the spatial patterning of NPs. However,
this experiments have been carried out in model environments different from the real
biological ones. Then, when NPs conjugates are brought to their application media, lack
of stability is a common observation. Considering the broad range of technological and
biomedical applications of AuNP-biomolecules conjugates to date, it appears as a critical
issue to move towards high stability and solubility in the aqueous media. Citratestabilized Au nanoparticles and derivatives, probably the most used NPs in biomedical
applications, have been functionalized with a range of different peptide ligands and
environments. The aim of these studies is to elucidate the factors responsible for the
stability conferred by these peptides, which has mainly been followed by variation of the
UV-Vis absorption spectra, surface charge and observation of precipitation. A model
based on electrostatic interaction vs. Brownian motion has been proposed to explain the
apparent critical aggregation of these gold nanoparticles.
Poster Session P2
INCORPORATING LANTHANIDES IN SILICA COLLOIDS
Johan Stiefelhagen and Dannis ‘t Hart, Soft Condensed Matter, Debye
Institute, Utrecht University, Utrecht, The Netherlands;
[email protected]
281
Lanthanide doped silica colloids have several applications: the highly luminescent
particles could be used as dopants in photonic crystals to probe their properties, as
probes inside cells or as particles for studying colloidal systems. In this research a new
method is shown to synthesize lanthanide doped silica particles in a water-in-oil
microemulsion. Mean particle diameter is approximately 50 nm and the size
polydispersity can be as low as 3.3%. Lanthanide presence is confirmed by
274
photoluminescence and EDX measurements. Concentrations are estimated at 10^4
lanthanide ions per particle (~0.6 at%). With observance of the small diameter this is a
lower size polydispersity than has been achieved in two other known synthesis
procedures used to incorporate lanthanide ions in silica colloids, namely acid based silica
synthesis and modified Stober synthesis. In a basic environment such as in a
microemulsion lanthanides precipitate as a hydroxide. In this research this is prevented
by the use of lanthanide complexes: before incorporation lanthanide ions are enveloped
with four large molecules, called ligands, which protect the ion from the basic
environment. t is shown that this new incorporation method can be used on several
species of lanthanides, including neodymium, samarium, europium, terbium and erbium,
or even with combinations of them. Furthermore lifetime measurements of some specific
lanthanide transitions are shown.
Poster Session P2
DETERMINING THE MOISTURE-INDUCED GLASS TRANSITION IN
AMORPHOUS PHARMACEUTICAL POWDERS
Frank Thielmann and Daniel J. Burnett, Surface Measurement Systems,
Ltd., Allentown, PA, USA; [email protected]
282
Low molecular weight amorphous materials will typically revert to their more stable
crystalline state over a certain temperature range. Additionally, ever-present water vapor
can act like a plasticizing agent, thus significantly lowering the glass transition
temperature and cause spontaneous phase transitions and lyophile collapse. Therefore,
determining the necessary threshold humidity conditions to prevent a glass transition is
critical for storage and processing of amorphous materials. In the current study
amorphous lactose was exposed to a linearly ramped humidity profile from 0% to 90%
relative humidity (RH). The glass transition is marked by a clear shift in the water
sorption behavior of the sample as the dominant sorption mechanism shifts from surface
adsorption to bulk absorption. This was performed for a series of ramping rates. This
allows extrapolation to a ramping rate of zero, resulting in an inherent glass transition RH
of 30% (+/-1%) RH at 298 K for amorphous lactose. Similar experiments were performed
for spray-dried salbutamol sulfate. For salbutamol sulfate, the moisture induced Tg was
measured over a range of temperatures.
Poster Session P2
CHARACTERIZATION AND EVALUATION OF ZNO POWDER
COMBINED WITH CNTS IN ORGANIC DYE-SENSITIZED SOLAR
CELLS
Yu-Jui Wu1, Mi Chen2, Chang-Lin Huang1, and Horng-Show Koo1,* ;
1
Department of Optoelectronic System Engineering, Ming-Hsin University of
Science and Technology, Hsinfong, Hsinchu 304 Taiwan, R.O.C.;
2
Department of Materials Science and Engineering, Ming-Hsin University of
Science and Technology, Hsinfong, Hsinchu 304 Taiwan, R.O.C.;
283
275
Characterization and evaluation of ZnO powder combined with carbon nanotubes (CNTs)
in the organic dye-sensitized solar cells were analyzed and demonstrated. The porous
ZnO particles were prepared slurry in the solution of PEG and de-ionized water by a
physical route and adjusted into paste with appropriate viscous behavior for coating. The
high-quality and high-purity carbon nanotubes have been synthesized by plasma
enhanced chemical vapor deposition and purified by microwave digestion method. The
purity and nano-size particles of carbon nanotubes will remarkably and greatly affect the
thin-film and solar-cell characteristics of the organic dye-sensitized solar cells. The paste
of the ZnO powders combined with different weight ratio of carbon nanotubes were
printed on the surface of ITO-coated glass substrate by the doctor blade technique. The
various weight ratio of carbon nanotubes in porous ZnO powders will result in the
variation of the optoelectronic characterization, conversion efficiency and short-circuit
current, of the organic dye-sensitized solar cells. These improved phenomena maybe
attributed to the enhanced adsorption of ZnO powders and carbon nanotubes for organic
dye and re-ox electrolytic substances in the solar cells
Poster Session P2
IMPACT PROPERTIES OF DIFFERENT LAMINATE CONFIGURED
HYBRID POLYMER NANOCOMPOSITES
S. K. Srivastava, I P Singh; Instrument Design Development Center, Indian
Institute of Technology Delhi-110016, India; [email protected];
[email protected]
284
Hybrid polymer nanocomposites constituting of nanoclay, epoxy materials and glass
fibers in different laminate configurations forms are specially used for multidirectional
loadings in structural applications. The mixture of nanoclay powder (Southern clay
products, USA) and epoxy was prepared using magnetic stirrer and sonicator. The three
layer composites with possible combinations of chopped strand mat and woven roving
glass fiber were made using vacuum resin transfer molding method. The optimization of
weight percentage of nanoclay was done to get the better intercalation. X-ray diffraction,
transmission electron microscopy (TEM) and izod impact test were done for the analysis.
It was found that approximately 2% of nanoclay gives better d-spacing value of 4.2 nm.
Intercalation nature of nanoclay in epoxy was confirmed by TEM. A better modification
in impact properties was found in different laminate configurations.
Poster Session P2
FLUORESCENT AU CLUSTERS SURROUNDED BY DENDRITIC
OLIGOSACCHARIDE SHELLS AND THEIR OPTICAL PROPERTIES IN
WATER
Mathias Lakatos, Dietmar Appelhans, Fuat Aksoy, Wolfgang Pompe;
Technische Universität Dresden, Institute for Materials Science, 01062
Dresden, Germany, [email protected]
285
Amphiphilic core shell structures based on oligosaccharide-functionalized dendrimers
276
have been used for the encapsulation of highly fluorescent gold nanoclusters. In
comparison to semiconductor quantum dots or organic fluorophores, these structures
offer some advantages as fluorescent labels to overcome problems like toxicity, surface
passivation, photoblinking or easy photobleaching. Here, we report a very simple two
step technique for the preparation of functionalized gold nanoclusters with tuneable
emission wavelength and with a high synthetic yield. In a first step, the gold nanoclusters
were prepared in an organic solvent in the presence of various stabilization agents. Then,
these clusters were embedded in oligosaccharide-functionalized dendrimers from the
fourth generation and higher to ensure water solubility. In comparison to other published
processes, formation of bigger nanoparticle agglomerates, resulting in a plasmon signal
and quenching the fluorescence, could not be seen. Further, the additional introduction of
anchor groups and biological receptor have been realized besides the establishment of
various oligosaccharide shells on the dendrimer surface which did not influence the
optical properties of the Au nanoclusters. First transfection experiments with Hela cells
show the high potential of these dendrimer stabilized gold nanoclusters as a new class of
fluorescence markers.
Poster Session P2
THE PHOTOELECTRIC RESPONSE OF HYDROPHOBIC GOLD
NANOPARTICLES AND GOLD/SILICA MONOLAYERS
Wensheng Lu, Wei Shi, Junke Tang and Long Jiang, Beijing National
Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy
of Sciences, Beijing, 100080, P.R. China; [email protected];
[email protected]
286
A monolayer of dodecanethiol-capped Au nanoparticles (NPs) about 3 nm in diameter
obtained by Langmuir technique spreading in a gap between two gold electrodes on a
silicon plate was found to enhance significantly the lateral electron transportation as the
number of NPs increased. The electric current increases from 10-11 to 10-9A (~ 100 times
in mgnitude) at an applied bias of 5 V in the dark. Especially interesting, the
photoinduced current increase from 10-11 to 5×10-9 (~ 500 times in mgnitude) at 5V
applied bias upon the green light illumination, close to the Surface Plasmon Resonance
(SPR) absorption of Au NPs film. We further reported an efficient hydrophobic treatment
of monodisperse gold nanocrystal with water-soluble silica (Au@SiO2) and investigated
its photovoltaic characteristics. The hydrophobic Au@SiO2 nanocrystal was obtained by
forming Si-O-Si bond with silane-coupling reagent octadecyltrichlorosilane (OTS) and
finally had a hydrocarbon chain on silica surfaces of the nanocrystal. The hydrophobic
Au@SiO2 nanocrystals could easily self-assemble robust and close packed 2-D arrays on
the air-water interface. Transmitting electron microscope (TEM), atomic force
microscope (AFM) and Ultraviolet-visible spectroscopy (UV-vis) were employed to
investigate the morphologies and optical properties of the 2-D film. Then the Au@SiO2
films were transferred onto conductive transparent indium tin oxide (ITO) to construct an
ITO-gold film-ITO device. We made a research on effect of different gold film layers on
the dark current and light current of the device at the ambient temperature. The
experimental results showed that both dark and light current signals would enhance
significantly with the increasing of gold film layers.
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Poster Session P2
GOLD NANOPARTICLE DEPOSITION VIA GAS-EXPANDED LIQUIDS
FOR IMPROVED MICROMACHINE RELIABILITY
Kendall M. Hurst, Christopher B. Roberts, W. Robert Ashurst, Auburn
University, Department of Chemical Engineering, 212 Ross Hall, Auburn, AL
36849, USA; [email protected], [email protected]
287
The technology to fabricate microelectromechanical systems and micromachines has
been around for over two decades. Unfortunately, only the most basic MEMS and microdevices are utilized commercially due to persistent reliability issues such as “stiction,”
the permanent adherence of two contacting micromechanism surfaces. This adhesion is
caused by the inherent attractive forces between relatively smooth, microscale features or
between a microstructure and the underlaying substrate. Although the development of
organic self-assembled monolayers as anti-stiction coatings has nearly eliminated
stiction, liquid-phase deposition of these monolayers presents several drawbacks
including cost, repeatability, and process sensitivity. This work describes a novel
processing method for the deposition of dodecanethiol-capped colloidal gold
nanoparticles onto micromechanical devices to reduce stiction by increasing the
roughness of micro-structured surfaces. Previous attempts to reduce stiction by reducing
contact surface area were abandoned due to only moderate success. Therefore, this
method contradicts the conventional wisdom that adhesion reduction is only achieved by
chemical alteration. Nanoparticles are deposited onto all surfaces of a micromechanical
device chip using gas-expanded liquids, which experience a reduction in solvent strength
with increased gas headspace pressure allowing for particle precipitation. Due to the
miniscule size of the nanoparticles, attractive van der Waals forces dominate gravitational
forces allowing precipitated particles to attract to all surfaces of the device. Immediately
following deposition, the CO2/solvent mixture is heated to the supercritical state in order
to remove the liquid-vapor interface. Doing so effectively eliminates evaporative effects
which may disturb nanoparticle films and capillary forces that may destroy
microstructures on the device. Following depressurization, the dry, nanoparticle-coated
device is removed for analysis. Gold nanoparticle coatings on micromechanical
cantilever beam arrays are evaluated via contact angle measurements, detachment length
and work of adhesion measurements, SEM, and AFM. SEM imaging affirms the
uniform, conformal coating of nanoparticles onto microdevice components. Contact
angle and work of adhesion measurements are compared to that of
octadecyltrichlorosilane and perfluorodecyltrichlorosilane self-assembled monolayers.
The results indicate that the application of colloidal gold nanoparticles onto
micromechanical devices reduces the work of adhesion compared to natural silicon oxide
layers by more than four orders of magnitude.
Poster Session P2
PROBING THE TRANSITION MECHANISM BETWEEN QUASISPHERICAL AND CUBIC GOLD NANOPARTICLES
Ekaterina Dovgolevsky and Hossam Haick, Department of Chemical
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Engineering and Russell Berrie Nanotechnology Institute, Technion – Israel
Institute of Technology, Haifa 32000, Israel; [email protected];
[email protected]
Metallic nanoparticles have been attracting a great interest because they have potential
applications in many fields including sensors, catalysis, nanoelectronics and information
storage. In recent years, various metallic nanoparticles with different morphologies, such
as spheres, cubes, and pyramids, have been prepared. However, controlling their
morphology, improving the methods of synthesis, and understanding their growth
mechanism, still remain a challenge. In this study, we adapted an aqueous seed mediated
growth method to explore shape transformation of quasi-spherical Au seeds to nanocubes
in a direct and continuous manner. The intermediate growth products quenched at
different reaction times of growth process were analyzed by High Resolution
Transmission Electron Microscopy (HRTEM) and UV/Vis spectroscopy. At the very
early growth stages, the results show formation of <28 nm monodispersed truncated
cubooctahedral Au nanoparticles, faceted with the both {100} and {111} facets. At a
critical size, estimated as 28 nm, the truncated cubooctahedral nanoparticles are
transformed to 28-29 nm {100} faceted cubic nanoparticles. From the point on, the cubic
nanoparticles further grow up, with no changes in their shape. We ascribe these
observations to a scenario in which the kinetically-controlled growth mode of the
nanoparticle is significantly affected from the surface self-diffusion of metal adatoms,
especially when the adatom’s self-diffusion distance is comparable with the
nanoparticle’s size.
Poster Session P2
EFFECT OF CTAB ON THE SYNTHESIS OF PHOTOLUMINESCENT
SILVER NANOPARTICLES
G. B. Teh, B. Y. Foo, N. Saravanan, C. L. Kho; Department of Bioscience
and Chemistry, Universiti Tunku Abdul Rahman, Kuala Lumpur, Malaysia;
[email protected]
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Silver is a noble metal noted for its inert chemical reactivity in its bulk form. It is noted
that silver nanoparticles with increased surface areas exhibit notable properties which are
very different from its bulk form. Nanosilver particles in solutions or suspensions are
used due to their effective action on the cellular metabolism and inhibiting cell growth.
Nanosilver particles exhibit luminescence intensity at 465nm and the wavelength is sizedependent. Various techniques can be employed in producing nanosized silver particles
such colloidal systems using cationic and anionic surfactants, microwave synthesis
method and laser-pulsed technique. Cationic surfactant cetyltrimethylammonium bromide
(CTAB) has been reported to be a stabilizer as well as a good micelle formation
surfactant which will provide stable capping availability for positively-charged silver
nanoparticles. Thus, the particle size control and size distribution are of prime interest
where they can be achieved via varying the synthetic techniques, reducing agents and
stabilizers. We report here the effect of varying the concentration of AgNO3, NaOH and
NaBH4 via the employment of CTAB as the surfactant molecules.
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Poster Session P2
CONDUCTING SILVER NANO-HYBRID PARTICLES
Andrij Pich, H.-J. Adler, TU-Dresden, 01069 Dresden; Germany, W.-J.
Fischer, Alexander Türke, Fraunhofer IPMS, 01109 Dresden, Germany;
[email protected]
290
In the last few years stable dispersions of metal nanoparticles become more and more
important. Especially in the field of material deposition, like ink jet printing of
conducting traces or connectors, stable and low temperature curing particles are needed.
Commercialized nanoparticles of silver and gold are stabilized with ligands to prevent
agglomeration. They are normally protected either sterically or electrostatically. The
protecting layer on the particle surface has to be removed by heat to achieve high
conductivity. A high temperature process with temperatures above 180°C is not possible
for most of the commercially available foils. Also the adhesion of these particles to foils
is very bad without an adhesion promoter. To avoid high temperature processes and
adhesion problems we propose a new approach that requires stabilization of metal
nanoparticles on polymer particle surface. Hybrid particles combine the advantage of
organic polymer particles, like film formation, and inorganic metal nanoparticles with
special properties like conductivity or special optical behavior. We report on the
modification of polymer latex particles with silver to achieve conducting core-shell
particles. The latex particles were synthesized in an emulsion polymerization process.
The surfactant-free polymerization process allows localization of the functional groups
on the polystyrene particle surface due to the hydrophilic nature of selected functional comonomers. Obtained particles have been characterized by DLS, SEM and analytical
centrifuge. The size of the polymeric particles varies between 100 and 600 nm in
diameter. To deposit silver on the surface of polymeric particles two-step procedure has
been used. In the first step silver nitrate was added to coordinate the silver ions to the
functional groups on the polymer particle surface via electrostatic forces, since the
surface layer of the latex particles has negative charge. In the second step a reducing
agent was added to transform complexed Ag+ ions into reduced form Ag0. The influence
of different reaction parameters (temperature, pH, irradiation with ultrasound,
concentration of reducing agent) on the morphology and properties of composite particles
has been studied. Conductivity measurements (four-point probe) were performed to
investigate the electrical properties of the obtained films.
Poster Session P2
SYNTHESIS OF NANOPOROUS NETWORK MATERIALS WITH HIGH
SURFACE AREAS FROM THE COOPERATIVE ASSEMBLAGE OF
ALKYL CHAINS-CAPPED METAL/METAL OXIDE NANOPARTICLES
Driss Mrabet, M. Hassan Zahedi-Niaki and Trong-On Do; Department of
Chemical Engineering, Laval University, Quebec G1K 7P4 CANADA,
[email protected]
291
The self-assembly of mono-disperse nanoparticles (NPs) into well-defined threedimensional nanostructure has rapidly attracted a growing interest. In particular,
280
nanoporous metal/oxide NP solids with controlled particle sizes could provide catalytic
performance over conventional catalysts. Furthermore, the interaction between metal NPs
and metal oxide NPs has gained significant interest owing to new properties that arise at
the metal/metal oxide interface. This type of catalysts exhibits high catalytic activity
toward different types of reactions, such as the NOx reduction and the CO oxidation at
low temperatures. High catalytic activity might be due to a synergetic interaction between
metal NPs and nano-support at the interface, such that the support does not act as an inert
carrier, but intervenes in the catalytic reactions. However, only a few examples of this
type of porous metal/metal oxide particles are yet known. In order to explore new
properties arising at the interface between metal nanoparticle and metal oxide
nanoparticles, herein, we report a simple route for the synthesis of a new class of
metal/metal oxide NPs solids with high surface area and interparticle porosity through the
cooperative assembly of pre-synthesized hydrophobic NPs of both metal and metal oxide.
The synthesis is performed in organic solvent media. Owing to capping with the alkyl
chains, the resulting NPs are hydrophobic, weak interactions in between and highly
dispersed in solvent. A homogeneous mixture of both metal and metal oxide NPs can
therefore be obtained. Based on this concept, a variety of nanoporous multi-component
solids of both metal and metal oxide with homogeneous dispersion in between can be
synthesized, since each NP component is individually pre-synthesized with controlled
particle size. The high surface area and new properties at the metal/oxide NP interface of
such multi-component NPs solids could make them interesting systems for future studies
in many fields of advanced nanotechnology, particularly in catalysis, chemical biological
sensors, optics and electronics
Poster Session P2
SYNTHESIS AND SELF-ASSEMBLY OF UNIFORM RARE EARTH
ORTHOVALADATE OR MOLYBDATE NANOCRYSTALS USING A
SOLVOTHERMAL APPROACH
Thanh-Dinh Nguyen, Driss Mrabet, and Trong-On Do; Department of
Chemical Engineering, Laval University, Quebec G1K 7P4 CANADA,
[email protected]
292
Mixed metal oxide nanocrystals raise the possibility of combining the properties of
individual components with new properties that arise from the interactions between size
and composition building blocks. Furthermore, assembling mixed oxide nanoparticles
into a nanoporous material not only combines the properties of the buiding blocks but
also explores the development of new collective properties that may emerge from
nanoparticle-nanoparticle interaction as a function of their composition. Among
important mixed metal oxide nanoparticles (NPs), rare earth-orthovanadate or -molybdate
compounds have been much attention, essentially due to their wide range of applications,
essentially in catalysis, solar cells etc. Although various techniques have been developed
to synthesize this type of materials, it still challenging to synthesize these NPs with
controllable size and sharpe. Herein, we report a new approach for the synthesis of
uniform rare earth orthovanadate/molybdate nanoparticles with small and uniform
particles size, such as CeVO4, YVO4, Ce2(MoO4)3, Y2(MoO4)3 NPs, using a solvothermal
method. The synthetic process consists of the preparation of separate clear toluene
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solutions containing cationic RE-oleate complexes and anonic MO4-TOA complexes
(where RE = rare earth ions, M = V, Mo, and TOA+= tetraoctylammonium), followed by
the mixture of these solutions and solvothermal treatment in the presence of capping
agents. Various techniques including XRD, N2 adsorption, TPO, TGA, FTIR, TEM, XPS
were used to monitor the physico-chemical properties of these nanoparticles. The results
revealed that the prepared mixed metal nanoparticles exhibits small particles sizes with
narrow size distributions (4-6 nm). Futhermore nanoporous materials obtained by selfassembly of the mixed metal oxide nanoparticles yield high surface area, uniform
nanopore size and high oxygene storage capacity, which are considerable as high
potentials in catalysis, for exemple, in three-way catalytic converters to clean up
autmotive exhausts. Based on this synthesis approach, a variety of multi-component
nanoparticles with controled particle size as well as their self-assembly yielding desired
structure can be synthesized.
Poster Session P2
CARBON NANOSPHERES: "GREEN" SYNTHESIS,
CHARACTERIZATION, AND GROWTH KINETICS
M. Doorley1, S. R. Mishra1, M. Laradji1, R. Gupta2, and K. Ghosh2
1.The Department of Physics, The University of Memphis, Memphis, TN, 2.
Department of Physics, Astronomy, and Materials Science, Missouri State
University, Springfiled, MO; [email protected]
293
Carbon is a versatile element because it can form various structures with unique
properties and applications. The discovery of new forms of carbon such as fullerenes
has fueled the investigation of carbonaceous materials. Increasingly these materials are
finding applications in areas such as nanodevices, batteries, drug delivery, etc. Several
synthesis techniques have been used to produce spherical pure carbon spheres. These
include ball milling, arc discharge, chemical synthesis, and pyrolysis. All these
techniques produce bulk CNSs with relatively inert surfaces, which make surface
modification almost unavoidable before using them as supports or templates.
Furthermore, controlling the size of CNSs has been challenging. Under hydrothermal
conditions, at moderate temperatures in the range 160-180 oC and under pressures
between 8-10 atm, sugars such as glucose undergo chemical transformations forming
homogeneous carbon spheres. These extreme conditions cause glucose molecules to
undergo dehydration-induced polymerization and carbonization forming monodispersed
CNSs. The as- produced CNSs are porous and naturally hydrophilic with a large
presence of surface hydroxyl groups, which can help in direct functionalization of the
surface without requiring further modification. This hydrothermal synthesis technique
has several advantages such as moderate temperatures, good yields, and most importantly
an environmentally benign process; a “green” technique. However, the study of the
growth mechanism of carbon nanoparticles synthesized using hydrothermal techniques is
somewhat elusive. The main hurdle in understanding this mechanism is that the reaction
takes place in a closed inaccessible vessel. Herein, we report in a study of the growth
kinetics of amorphous CNSs synthesized using a hydrothermal technique. The growth of
CNS was studied by evaluating transmission electron microscope images as a function of
hydrothermal reaction time and temperatures. Raman spectra revealed the presence of
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short-ordered graphitic nanostructures in an amorphous carbon matrix. FTIR
spectroscopy confirms the carbonization of glucose and shows the presence of surface
hydroxyl groups on CNSs. Based on various experimental observations it is proposed that
the growth of CNSs is dictated by a reaction-controlled mechanism where long chain
glucose-based oligomers bond to the CNS surface.
Poster Session P2
HETEROPHASE POLYCONDENSATION OF POLYIMIDES IN IONIC
LIQUIDS
Hendrik Frank, Ulrich Ziener, Katharina Landfester; Institute of Organic
Chemistry III – Macromolecular Chemistry and Organic Materials, University
of Ulm, 89081 Ulm, Germany; [email protected]
294
Ionic Liquids (ILs) are organic salts with melting points below 100 °C. They are widely
used in numerous chemical applications. Due to their almost nondetectable vapour
pressure, ionic liquids are suited as solvents. In the last few years, there were a lot of
reports about the usage of ILs as solvents in different kinds of polymerisations, i.e.
solution polymerisations of butyl methacrylate and methyl methacrylate. There are also
some reports about direct polycondensations in ionic liquids with different types of
monomers. These papers mainly describe the polycondensation of carboxylic acids and
diamines to produce polyimides. However, in these papers, the polymer is synthesized in
solution and precipitated after the polymerisation by the addition of methanol or other
solvents. We report the heterophase polycondensation of different tetracarboxylic acids
and aromatic diamines in imidazolium-based ionic liquids as continuous phase in order to
obtain polyimide nanoparticles. The agents can be emulsified in the IL without the use of
any surfactant due to the amphiphilic character of the IL. The reaction medium can then
be heated to high temperatures in order to start the reaction. The reaction takes place
without the addition of any extra components as LiCl or pyridine. The obtained
polyimide was characterized by IR spectroscopy. The molecular weight of the polymers
is determined by GPC. TEM and SEM micrographs show homogeneous morphology of
nanoparticles. The polymer film formation properties have been analysed by AFM.
Poster Session P2
POLYMER CORE-SHELL NANOPARTICLES DOPED WITH
LUMINESCENT COMPLEXES
Jessie Desbiens, Carmen M. Tibirna and Anna M. Ritcey, Département de
chimie, Université Laval, Québec, Canada; [email protected]
295
Luminescent europium and erbium complexes, Eu(tta)3phen and Er(tta)3phen were
synthesized and doped into polystyrene nanoparticles prepared by miniemulsion
polymerization. The resulting particles were characterized by scanning electron
microscopy, UV-visible spectroscopy, X-ray diffraction, dynamic light scattering and
fluorescence spectroscopy. Particles with a diameter around 100 nm are typically
obtained. It is shown that the lanthanide complexes are incorporated into the polymer
host as non-crystalline molecular dispersions at concentrations below 15 weight %. At
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higher doping levels, inhomogeneous materials are obtained with the excess lanthanide
complex existing as a second crystalline phase. Fluorescence measurements indicate that
the luminescence properties of the complexes are maintained within the polymer
matrices. The first generation doped polystyrene particles are not cross-linked and are
therefore readily swollen or even dissolved in relatively large number of solvents. The
conditions under which the particles can be manipulated without the possible loss of the
trapped lanthanide complex are thus quite limited. For this reason, a second generation
of particles has been prepared. The general strategy consists of the preparation of coreshell particules by the addition of polydivinylbenzene shell in order to stabilise the doped
polystyrene cores.
Poster Session P2
ANALYSIS OF MONOMER COMPOSITION IN COPOLYMER
MICROGEL PARTICLES
Hani Nur*, M.J. Snowden, V.J. Cornelius and L.S. Benée, Medway Sciences,
School of Science, University of Greenwich at Medway, Chatham Maritime,
Kent, UK, ME4 4TB, UK; [email protected]
296
Homopolymer [poly(N-isopropylacrylamide) [pNIPAM], poly(4-vinylpyridine) and
poly(butylacrylate)] and copolymer [poly(N-isopropylacrylamide/4-vinylpyridine) and
poly(N-isopropylacrylamide/butylacrylate)] microgels were prepared by surfactant-free
emulsion polymerization. The copolymer microgels were synthesized using percentage
composition of 4- vinylpyridine / butylacrylate in the range of 7.5 – 90 % w/w relative to
NIPAM in the original reaction mixture. Freeze-dried samples of the microgels were
analysed by Raman and NMR spectroscopy. The Raman spectral profiles of the different
microgels were compared and contrasted in the 100-3600 cm-1 wavenumber region, and
in the range of δ 0-300 ppm (13C) chemical shift region with solid state NMR. The
Raman and NMR spectra of both the copolymer microgels were also subjected to
statistical analysis (least-square fitting of each monomer to the copolymer spectrum) for
the semi-quantitative analysis of the monomer composition of the copolymer microgels.
Results has shown that for both the copolymer microgels, differing in monomer
composition, Raman spectroscopy can be employed as a quick/easy method to ensure that
co-polymerization has occurred and also to determine, semi-quantitatively, the
percentage incorporation of the 4- vinylpyridine / butylacrylate monomer. A good
correlation exists between the Raman and NMR results, Raman spectroscopy however is
much less time consuming (Raman spectral acquisition time is < 10 mins), the
measurements are easy to make and very small quantities (less than 1 mg) of the material
under investigation are required. This compares with the experimental measurements of
12-16 hours and 100-200 mg of sample that are required for the NMR experiments.
Poster Session P2
NOVEL SURFACTANT MICROGEL PARTICLES: SYNTHESIS AND
APPLICATIONS
Hani Nur*, M.J. Snowden, V.J. Cornelius and L.S. Benée, Medway
297
284
Sciences, School of Science, University of Greenwich at Medway, Chatham
Maritime, Kent, UK, ME4 4TB; [email protected]
Poly(N-isopropylacrylamid) [pNIPAM] copolymerised with surfactant type monomers at
a concentration of 10% w/w were prepared by surfactant free emulsion polymerisation.
The surfactant co-monomers chosen vary by their organic chain length as this should
affect how the particles behave in aqueous and non-aqueous solvents. The effect of
adding a surfactant type co-monomer was investigated with respect to their
physicochemical properties and their dispersibility in different solvents. The dispersibility
behaviour of homopolymer [pNIPAM] and copolymer Poly(pNIPAM/acrylic acid) in
different solvents was also investigated. These microgel particles have shown useful
application in the removal of water from biodiesel prepared from rape seed. The Karl
Fischer experiment showed that microgel particles can be used to reduce the water
content in biodiesel to an acceptable level.
Poster Session P2
MONODISPERSE POLYMER PARTICLES: CHARACTERISATION AND
SELF-ASSEMBLY IN SUSPENSION
Keith Redford, Helge Kristiansen, Cathrine B. Nilsen and Martin F.
Sunding* Conpart as, Lahaugmoveien 1, 2013 Skjetten, Norway. * SINTEF,
PO box 124, 0314 Oslo, Norway; [email protected]
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Micrometer sized polymer particles are used in different applications within
microelectronics and micro-system applications. Conpart AS is a Norwegian company
specializing in the manufacturing, characterization and application of micrometer sized
polymer particles with unique properties for use in electronics and micro-system
applications. Some of the unique properties of these particles include an extremely
narrow size distribution, a wide variety of possible chemical compositions, highly porous
particles or “polymer-matrix” particles filled with different oxides or metals. Also the
surface properties are highly uniform both particle to particle and batch to batch which
makes it easy to provide different types of surface coatings, including metal plating.
Consequently it possible to manufacture particles with a large range of different
mechanical, electrical, optical and other properties. Two of the most demanding
applications where such particles are used are as spacers for flat panel displays as
conductive particles in for anisotropic conductive film (ACF) in the metal plated form.
Some of the most critical properties for the particles in both of these applications are the
particle size and size distribution and mechanical properties. This poster will present the
challenges in defining particle size and size distribution and will the particle’s ability to
self assemble in 2 and 3 dimensions. The first main section will deal with
characterization of particle size, size distribution and “off-size” particles. With “off-size
particles” we mean particles that have a particle diameter which is more than 10 % off the
diameter of the main population. Different characterization techniques have been used,
including optical techniques, scanning electron microscopy, laser diffraction and electric
zone sensing (Coulter principle). The strength and weaknesses of the different
techniques with respect to characterization of the polymer particles will be discussed. The
particle can easily be assembled in two or three dimensional “crystal like” structures this
285
means that optical microscopy can be used to measure chains of particles. This means
that, despite the inherent limitations caused by the wavelength of light, optical
measurements can give reliable size data. The fact that the particles are made of a
polymer material also means that the particles environment will influence on the actual
measured particle size. The change in size observed from SEM with a high vacuum
where the particles are fully dried out, to optical measurements with the particles in water
can change the measured diameter by more than 5 %. A Flow Particle Image Analyzer is
shown to be a powerful instrument to identify individual large particles but is limited in
determination of size distribution. Coulter technique is very powerful in measuring the
size of individual particles but is confused by pairs of particle passing through the
measurement zone together. Light scattering techniques give a global picture but can not
identify individual off size particles. In conclusion a combination of techniques is needed
to describe accurately size and size distribution. No one technique alone can be used to
define a sample of particles.
Poster Session P2
FORMATION MECHANISMS AND PROCESSING CONDITIONS FOR
ENGINEERED SPIDER SILK MICROSPHERES
Andreas Lammel*, Ute Slottaº and Thomas Scheibelº; [*] International
Graduate School of Science and Engineering, Technische Universität
München, 80333 München; [º] Chair of Biomaterials, Universität Bayreuth,
95447 Bayreuth; [email protected]; [email protected]
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Spider silk is a material consisting of very large proteins (> 200 kDa) with unique
structural stability, mechanical toughness and elasticity. Along with their biocompatibility
and biodegradability, silk materials have a high potential for biomedical applications.
Especially in the area of new innovative and effective drug delivery systems spider silk
proteins are very well suited because of their possible functionalization and coupling of
active agents. Here, we report on the influence of physicochemical factors on structure
formation of recombinantly produced engineered spider silk protein eADF4(C16) (MW
47.4 kDa), mimicking the known sequence of the dragline compound ADF4 from the
spider Araneus diadematus. In order to unravel the mechanistic details of protein folding
and assembly we investigated effects of ions, pH, protein concentration and polypeptide
chain length on the assembly behavior. To elucidate, whether the examined chemical
parameters influenced aggregate morphology of eADF4(C16), we investigated the
aggregates microscopically using AFM, TEM and SEM. Strikingly, we were able to
detect two independent assembly forms of eADF4(C16): Nanofibrils with diameters
between 2 and 10 nm and microspheres with diameters of approximately 1 µm. Above
400 mM potassium phosphate (pH 8.0) solely microspheres could be detected. To find
out if microspheres size can be adjusted we analyzed the influence of mixing on
microsphere formation and employed several different methods for mixing eADF4(C16)
with potassium phosphate including dialysis, simple mixing with pipette and
micromixing within a T-mixing element. Upon mixing, the samples were analyzed with
laser diffraction spectrometry and scanning electron microscopy (SEM). Strikingly,
different sphere characteristics with respect to sphere sizes, size distributions and
formation of sphere clusters could be detected depending on the method of preparation.
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Controlled mixing within a micromixing device led to a smaller size distribution
compared to mixing with pipette or salting out by dialysis. Furthermore with increased
mixing intensity microsphere diameters decreased up to a minimal size of 250 nm. We
conclude that for the production of spider silk microspheres by salting out a high
concentration of potassium phosphate is required to obtain stable inert spheres. Spherical
growth stops, when the protein concentration is below the equilibrium of solubility
leading to the fact that the sphere diameter does not increase anymore. Generally, with
increasing protein concentration sphere size is increased. The sphere size can be further
adjusted by controlled micromixing inside a T-mixing element of eADF4(C16) with 1M
potassium phosphate (pH 8).
Poster Session P2
Luminescent Poly(Styrene) Nanoparticles Prepared by Fe3+ Catalyzed
Oxidative Polymerization in Aqueous Medium
Sun Jong Lee, Jung Min Lee, Dea Hyun Cho and Jung Hyun Kim,
Department of Chemical Engineering, Yonsei University, 134 Shinchondong, Sudaemoon-ku, Seoul 120-749, Republic of Korea ;
300
Styrene monomers can be polymerized by Fe3+-catalyzed oxidative polymerization inside
nano-sized styrene monomer droplets, i.e., nano-reactors, dispersed in aqueous medium,
which can be performed under acidic solution conditions with anionic surfactant.
Besides, we proposed a synthetic mechanism for the formation of the luminescent
poly(styrene) nanoparticles using Fe3+-catalyzed oxidative polymerization in aqueous
medium. This facile method includes a FeCl3/H2O2 (catalyst/oxidant) combination
system, which guarantees a high conversion (ca. 99%) of styrene monomers with only a
trace of FeCl3. The average particle size was ca. 50 nm, within a wide particle size
distribution (PDI = 2.09), which resulted in a good dispersion state of the poly(styrene)
nanoparticles in water. The prepared luminescent poly(styrene) nanoparticles were
soluble in various organic solvents. This indicates the resulting particles had better
processability for practical applications. These poly(styrene) particles showed various
unique properties, i.e., low molecular weight, photoluminescence properties, which were
much different from the existing poly(styrene) polymer prepared by conventional
emulsion polymerization. The UV-visible absorption and photoluminescence (PL)
spectrum were measured to investigate the light emitting properties of the prepared
poly(styrene) nanoparticle emulsions. According to non-normalized PL analysis, the
reduced total PL intensity of the polystyrene nanoparticle emulsions can be rationalized
by self-absorption in a wavelength range less than 600 nm. Thus, these luminescent
poly(styrene) particles may have potential practical applications in various electrical and
electro-optical devices, especially in polymer light emitting diodes (PLEDs).
Poster Session P2
A FACILE ROUTE FOR THE SYNTHESIS OF CRYSTALLINE YTTRIA
NANOSPHEROIDS
301
287
R.V Mangalaraja, S. Ananthakumar b, J. Mouzonc, Marta Lópeza, Carlos P.
Camurria, M.Odénc; Department of Materials Engineering, University of
Concepción, Concepción, Chile; aDepartment of Chemical Engineering,
University of Concepción, Chile; bNational Institute for Interdisciplinary
Science and Technology (NIIST), CSIR, Trivandrum- 695 019, Kerala, India;
c
Division of Engineering Materials, Luleå University of Technology, Luleå,
Sweden; [email protected]
Single phase, crystalline yttria nanospheroids have been synthesized through modified
nitrate-fuel combustion method in which ammonium sulphate is employed as shape
forming agent. Yttria nanospheroids with an average size below 50nm are achieved when
the as-prepared powder is calcined at 1100°C in oxygen atmosphere. The nanospheroids
are highly crystalline and cubic in nature. The effect of sulphate addition on the
morphological features, crystallinity, surface area and particle size are analyzed.
Poster Session P2
NANO-GRAINED ZIRCONIA CERAMICS THROUGH EXTRUSION OF
PARTICULATE GELS
Mangalaraja R.V., Sivaraman. Ra, Ananthakumar. Sb; Department of
Materials Engineering, University of Concepción, Concepción, Chile;
a
National Institute of Technology, Trichy, India; bNational Institute for
Interdisciplinary Science and Technology (NIIST), CSIR, Trivandrum- 695
019, Kerala, India; [email protected]
302
Nano-grained dense ceramics is a subject of research due to high hardness, compressive
strength and optical transparency. Use of nano size starting particles is usually
recommended for achieving nano-grained sintered ceramics. However, nano powder
compaction, sintering of nano powder compacts with out grain-growth using
conventional sintering techniques are few obstacles realized in making such nanoceramics. Colloidal processing has been successfully identified for developing dense
ceramics at low densification temperatures. In this work nano grained zirconia ceramics
through extrusion technology is attempted using the nano particulate mixed oxide gels in
the starting. Nano particulate alumina and zirconia gels have been prepared through solgel technique and zirconium oxy hydroxide precipitate was dispersed and homogenized
mechanically using high-shear mixer. Upon controlling the surface potential by adjusting
the pH, mixed oxide- nano-particulate gel mass was obtained. It was further subjected to
single screw extrusion for making zirconia ceramic rods and tubes. The extruded shapes
were sintered at 1350, 1450 and 1550°C/ 2h. The microstructure, mechanical strength,
wear resistance and Vickers’s micro hardness were studied and the results are discussed.
The gel bonded zirconia attained >99% theoretical sintered density at 1350°C. The SEM
analysis confirmed that the sintered zirconia has an average grain size of 700 nm. Such
nano-grained zirconia exhibit micro hardness as high as 20 GPa at 4.5 N. The wear
resistance behaviour of dense nano-grained zirconia ceramics at various loads and
durations of travel were evaluated using pin-on-disc technique. Gel assisted extrusion
appears to be promising for making nano-grained hard ceramics which is other wise
possible only by expensive methods such as spark plasma sintering and laser-plasma
288
assisted densification.
Poster Session P2
MINIEMULSION COPOLYMERIZATION OF STYRENE AND GAMMA
METHACRYLOXY PROPYL TRIMETHOXYSILANE
Z. H. Cao1,2,3, G. R. Shan2, G. Fevotte3, N. Othman3, E.Bourgeat -Lami1
1
C2P2/LCPP- UMR 5265 CNRS/CPE Lyon/UCBL – 43, Bd. du 11 Nov.
1918 - 69616 Villeurbanne, France. 2 State Key Laboratory of Polymerization
Reaction Engineering, Department of Chemical Engineering, Zhejiang
University, Hangzhou 310027, China. 3LAGEP, UMR 5007 CNRS/UCBL, 43
bd 11 Nov. 1918, 69622 Villeurbanne, France; [email protected]
303
In recent years, much effort has been done to synthesize organic-inorganic hybrid
colloids for applications in coating, adhesive, catalysis, drug delivery, etc. Among these
new materials, latexes incorporating reactive alkoxysilyl moieties capable of undergoing
cross-linking during film formation have drawn increasing interest. Indeed, the presence
of a post application crosslinking mechanism in waterborne coatings offers major
advantages with regard to the quality and the ultimate properties of the dried film.
However, previous works have shown that avoiding premature hydrolysis and crosslinking is challenging due to the high reactivity of the alkoxysilyl groups in the presence
of water. In this respect, miniemulsion polymerization has received great attention due to
the fact that each nanodroplet can be regarded as a batch reactor into which
polymerization takes place. Because there is little mass exchange between the droplets,
alkoxysilane monomers are protected from the aqueous phase which makes the control of
the hydrolysis and condensation reactions feasible. In this work, the kinetics of the
miniemulsion copolymerization of styrene (St) and γ-methacryloxy propyl
trimethoxysilane (MPS) was investigated by studying the effects of the MPS/St weight
ratio, the nature and amount of initiator, the suspension pH and the surfactant
concentration on the overall and individual monomer conversions. It was found that the
introduction of MPS accelerates the free radical copolymerization reaction due to its
higher propagation rate constant and higher water solubility, compared to styrene. On the
other hand, MPS decreases the copolymerization rate mainly during the second half of
the reaction. This is presumed to be due to the formation of alkoxysilane-rich copolymers
on the particles surface providing a barrier to radical’s entry. The rate of hydrolysis is
pH-dependent and for a given pH, the influence of the surfactant concentration on the
hydrolysis rate suggests that the interface between the latex particles and water is the
main locus of hydrolysis. 29Si solid state NMR analysis showed that the hydrolyzed
alkoxysilyl moieties did not condense under neutral conditions even for high MPS/St feed
ratios. Premature cross-linking could be also minimized under basic conditions but could
not be avoided in acidic media.
Poster Session P2
POLYMERIZATION OF 3,4 –ETHYLENEDIOXYTHIOPHENE IN
MINIEMULSION WITH FENTON´S REAGENT
Marcel Ruppert, Ulrich Ziener and Katharina Landfester, Institute of
304
289
Organic Chemistry III, Macromolecular Chemistry and Organic Materials,
University of Ulm, 89069 Ulm, Germany; [email protected]
Poly-3,4-ethylenedioxythiophene (PEDOT) as a highly attractive material for organic
electronics applications is an insoluble polymer, and therefore mostly used as aqueous
dispersion containing poly-(styrene sulfonate) (PSS) as surfactant and PEDOT particles
with a high percentage of the surfactant. The disadvantage of considerable amounts of
surfactant is a decrease in conductivity with increasing content of surfactant. Here, we
present the polymerization of EDOT with Fenton´s reagent via the miniemulsion
technique delivering an aqueous dispersion with a high solid content in combination with
a low percentage of surfactant. The properties of the dispersion and resulting film after
spin – coating have been analyzed by several techniques, e.g. DLS, TEM, AFM, etc.
Poster Session P2
EASY AND FAST ZERO-VALENT COPPER AND IRON
NANOPARTICLES SYNTHESIS
Maiby Valle-Orta1, David Díaz1*, Patricia Santiago-Jacinto2 and Edilso
Reguera Ruiz3, 1Facultad de Química; 2Instituto de Física de la Universidad
Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, CP 04510;
3
CICATA U-Legaria, Instituto Politécnico Nacional, Legaria 694, Colonia
Irrigación, Miguel Hidalgo, CP 11500, México D. F., México;
305
In the present work we prepared small copper particles of mean size smaller than 12 nm
by two methods. The first method consists in reducing CuSO4•5H2O to metallic Cu with
sodium borohydride (NaBH4) using triethylamine (TEA) as capping agent and
dimethylformamide (DMF) as solvent. The other method uses ethylene glycol as
dispersing medium where Cu(II) and Cu(I) ions are reduced by an intermediate species
(Na+B-(OCH2CH2OH)4) that is formed via the interaction of ethylene glycol with NaBH4.
The formed boron alcoxyde species gives an additional reducing capacity to the solution,
and also acts as a second surface modifier. These particles were characterized by X-RD,
FT-IR, Raman, Z-Contrast and HR-TEM. Also, it the electric potential on the surfaces of
the suspended nanoparticles in both solvents were determined. Both reducing reactions
take place in few minutes, at room temperature. The second synthesis method, was also
employed for the zero-valent iron nanoparticles (ZVI-NPs) preparation. These particles
were characterized by surface electric potential measurements, X-RD, Raman,
Mössbauer, EELS spectroscopies and HR-TEM. From the Mössbauer spectrum it is
possible to distinguish two ZVI-NPs populations. The smaller NPs are superparamagnetic
and they have an average diameter of ca. 5 nm. The other NPs are larger than 10 nm and
exhibit ferromagnetic behavior. Confinement effects will be discussed.
Poster Session P2
SIMULTANEOUS SYNTHESIS AND COATING OF
PHARMACEUTICAL NANOPARTICLES WITH L-LEUCINE IN THE
GAS PHASE
306
290
Anna Lähde, Janne Raula and Esko I. Kauppinen, Nanomaterials Group,
Laboratory of Physics and Center for New Materials, Helsinki University of
Technology, P.O. Box 5100, 02150 Espoo, Finland; [email protected];
[email protected]
Salbutamol sulphate and lactose nanoparticles have been prepared and coated with Lleucine in the gas phase using an aerosol flow reactor. The formation of the coated
particles was dependent on the operation temperatures and three different formation
mechanisms were observed. Below the temperature of L-leucine sublimation, formation
of the L-leucine layer on the core particle surface takes place via diffusion of L-leucine
molecules on the droplet surfaces during droplet drying. At intermediate temperatures,
the extent of sublimation of L-leucine depended notably on its concentration in the heated
zone of the reactor, and thus partial evaporation took place. At high reactor temperatures
complete sublimation of L-leucine was obtained and the L-leucine coating was solely
formed via vapour deposition on the core particle surface. The geometric mean diameter
of the core salbutamol particles was approximately 65 nm and of the lactose particles 120
nm. In general, particle size increased with the addition of L-leucine. The size
distribution remained the same or broadened when the coating layer of the particles was
formed via surface diffusion whereas notable narrowing of the distribution was observed
when the coating was formed via vapour deposition. Upon desublimation and
heterogeneous nucleation on the surfaces of smooth, spherical core particles, L-leucine
formed a discontinuous coating with leafy crystals a few nanometers in size. The
production of nanoparticles that are stable and do not fuse together, i.e. form large
aggregates, is a challenge. However, the coated nanoparticles produced with the aerosol
flow reactor did not sinter during the storage that was due the stabilizing effect of Lleucine coating.
Poster Session P2
FOUR CRYSTAL NUCLEATION MODELS: AN EVALUATION FOR
PRACTIVAL APPLICATIONS.
Ingo H. Leubner, Crystallization Consulting, 35 Hillcrest Drive, Penfield,
NY 14526-2411, USA, [email protected]
307
Four models have been proposed to relate the numbers of crystals formed to experimental
parameters. To control the crystal size of the product it is desirable to have a theory based
on fundamental science that allows simple modeling and accurate predictions. Of these,
the classical model is the best known, which focusses on nucleation rate. The primitive,
Klein-Moisar, and Balanced-Nucleation and Growth (BNG) models focus on the total
number of crystals formed and on crystal size. In the research lab, product development,
and manufacturing, the control of crystal size and yield must be related to practical
control parameters. These are temperature, crystal solubility, and reactant addition rate.
Two other control factors are added active materials that decrease or increase the crystal
size for otherwise fixed reaction conditions. For continuous crystallization, the residence
time must be added as a control parameter. Which presumed control parameters can be
ignored? The four nucleation models will be presented and compared for application in
research, product development, and manufacturing.
291
Poster Session P2
SILICON DOTS AND THEIR CYTO-TOXICITY
Kouki Fujioka1, M. Hiruoka2, N. Manabe1, A. Hoshino1, K. Sato3, K.
Hirakuri2, and K. Yamamoto*1; backen ri.imcj.go.jp;
[email protected]; 1International Clinical Research Center, Research
Institute, International Medical Center of Japan; 2Graduate School of Science
and Engineering, Tokyo Denki University, Japan; 3National Institute for
Materials Science, Japan
308
Quantum dots (QDs) have brighter and longer fluorescence than organic dyes. Therefore,
QDs have applied to biological experiments, and have capability to be applied to clinical
technology. Currently, among the several types of QDs, CdSe with a ZnS shell is one of
the most popular QDs to be used in biological experiments. However, when the CdSeQDs are applied to clinical technology, the potential of toxicological problems should be
considered. To overcome the problem, silicon nanocrystals could be one of candidates of
alternate probes. Silicon nanocrystals have been synthesized using several techniques
such as aerosol, colloids, chemical etching, laser pyrolysis, and plasma deposition.
Recently, novel silicon nanocrystals (nc-Si) were reported to be synthesized with the
combination methods, radio frequency sputtering method and hydrofluoric-etching
method, by Shinoda et.al. In order to assess the biocompatibility of the nc-Si, we
performed two different assays, cell viability/proliferation assay using the MTT (3-(4,5dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide) assay and cell membrane
damage assay using the lactate dehydrogenase assay. At the 1120 μg/mL of nc-Si (the
maximum concentration in the experiment), we could detected the decrease of
mitochondrial activity and the cell membrane damage significantly. We could detect the
nc-Si in 5.6 μg/mL, which was 200 times smaller than the significant toxicological
concentration. We concluded that attention should be given when nc-Si are applied to
living organisms in high concentration. This work is supported by the Ministry of Health,
Labor and Welfare of Japan and the Japan Association for the Advancement of Medical
Equipment.
Poster Session P2
PREPARATION AND EVALUATION OF LIPOSOMES
CONTAINING CLOVE OIL
Pilaslak Akarachalanon 1,Malee Bunjob1 Uthai Sothanapund 2,
Malai Satiraphan 3 Somlak Kongmuang4; 1Department of Medical Sciences,
Ministry of Public Health, Nonthaburi, Thailand, 11000; 2 Department of
Pharmacognosy, 3 Department of Pharmaceutical Chemistry, 4 Department of
Pharmaceutical Technology , Silpakorn University, Nakornpathom, Thailand,
73000; [email protected]
309
This research particularly focuses on preparation of liposomes which can efficiently
maintain stability and quality of clove oil. The research method used in this study can be
divided into five main steps. First, phosphatidylcholine(PC) was purified by using
292
techniques called column chromatrography and thin layer chromatrography. Each source
of PC was chemically evaluated following to Bartlett’s assay and densitometry. Second,
liposomes from three different sources of PC (i.e., purified PC from commercial
PC(PPC), commercial PC(CPC) and commercial high-purified PC(HPC)) were prepared
by using two different methods: thin film method and reverse evaporation. Four different
molar ratios of PC to cholesterol: 1:0, 9:1, 7:3 and 1:1 were investigated. Third, size and
size distribution control analyzed by extruding liposomes obtained from the two
techniques through syringe extruders. Fourth, a physical study of liposome containing
clove oil was performed using transmission electron microscopy (TEM), a chemical
study of eugenol was performed using gas chromatography (GC) and a stability study
was performed at a temperature of 4 degree Celsius for 3 months. Finally, release of
clove oil from liposome was studied using in vitro release apparatus. The research results
showed that PPC, CPC and HPC contained 63.01%, 34.60% and 63.98% of PC
respectively (the amounts were calculated by weight using inorganic phosphorus). The
densitometer data of three types of PC were shown to be in the same pattern as those of
Bartlett’s assay. Thin film method and 1:1 molar ratio of PC to cholesterol showed
multilamellar structure in the liposome from every source with size of 204.32±259.82,
246.99±125.16 and 243.45±165.76 nm. PPC, CPC and HPC respectively. The
multilamellar structure of liposome analyzed by using TEM showed that liposome from
PPC and CPC were similar to that from HPC while liposome prepared by CPC showed
incomplete multilamellar structure and high polydispersion index (PI) with size of
200.76±0.58, 200.23±0.19 and 200.35±0.43 nm with extruded PPC, extruded CPC and
extruded HPC respectively. The results showed that liposome extruded through a syringe
extruder had low PI since size of liposome was controlled by membrane. Moreover,
liposome prepared from PPC was tended to contain more clove oil than those from
commercial one (24.45% and 23.81% respectively, the amounts were calculated by
weight using eugenol). In addition, results of the chemical study showed that the amount
of eugenol contained in the liposome from PPC was nearly equivalent to that contained in
the HPC. After storage, in every condition for 3 month the morphology of liposome from
each type of PC did not change significantly. Liposome prepared by HPC or PPC could
maintain eugenol after stability evaluation with sustained release pattern within 48 hours
was released 64.99% of eugenol. Thus, PPC could be a good source for liposome as
comparing to HPC in term of quality of containing substance and stability.
Poster Session P2
IMAGING TRANSPARENT VITREOUS OF THE EYE USING NANO
PARTICLES
1,2
Noriyoshi Manabe, 3Satoru Yamamoto, 1Kouki Fujioka, 1Akiyoshi
Hoshino, 1Kenji Yamamoto, 1Research Institute, International Medical Center
of Japan, 2Japan Association for the Advancement of Medical Equipment,
3
Yokohama Sakae Kyousai Hospital Department of Ophthalmology;
1
Shinjuku-ku Tokyo 162-8655, JAPAN; [email protected];
[email protected]
310
Today many eye-diseases are known to be connected with pathologic and/or
physiological changes of the vitreous. Liquefaction of vitreous by aging may participate
in retinal tear which may lead to retinal detachment and then to no light perception. Some
293
macular edema may be related to vitreous traction to macula. Epiretinal membrane is
thought to be connected with posterior vitreous after liquefaction. But there is no
adequate method to observe transparent vitreous at daily clinical situations. And in case
of vitrectomy (a operation to cut and eliminate the vitreous), it is difficult and dangerous
to perform the operation to transparent vitreous. Several organic dyes including
fluorescein and indocyanine green have been used as imaging agents for retinal and
choroidal vessels, but they have difficulties for diagnosis for vitreous cavity. A turbid
corticosteroid, triamcinolone acetonide (TA), is also used as an imaging reagent on a
special case; that is for improvement of Diabetic Macular Edema or for vitrectomy. But
some side effects of TA (elevation of Intraoculara pressure, acceleration of cataract, and
endophthalmitis) have been reported. Therefore it is required to develop a new vitreous
visualizing method for ophthalmologists to observe the pathogenesis of vitreous. So we
applied some of nano particles (aqueous colloidal quantum dots (ACQDs) or polystyrene
dots) to a new method to visualize vitreous. To visualize the transparent vitreous, we use
nano particles. 0.1 ~ 0.15 ml of nano particles are injected into the vitreous cavity of an
enucleated porcine eye with a 27 gauge needle by way of pars plana of the ciliary body.
(Aging porcine eyes and young porcine eyes were used.) Afterwards observation of
vitreous with a slit lump microscopy was made. And moreover, a standard 3-port pars
plana vitrectomy of the eye was performed on a porcine eye mounted in a human head
model using a 20-gauge vitreous cutter and a hand-held light pipe. Just after injection of
nano particles, they dispersed into the vitreous cavity. Fluorescence emitted from the
nano particles reflected the structures of vitreous and it was observed with a slit lump
microscopy without any difficulty. Consequently details of the status of vitreous were
detected easily because ACQDs can be excited by a white lump which is commonly used
as a light source. A weiss ring, a subtle aging vitreous change, was observed easily in
front of the optic disc. And in case of vitrectomy, transparent vitreous stained red with
ACQDs made it easy to cut and aspirate the target lesion completely. The translucent red
fluorescence from ACQDs enabled us to confirm the location of other structures such as
the retina, blood vessels of retina, and ciliary body, and that resulted in reducing the risk
to injure other eye structures. These results suggested that a new method for
visualization of vitreous with nano particles is developed, and it will raise the cure rate of
eye-diseases.
Poster Session P2
ONE-STEP, NANOPARTICLE-MEDIATED BACTERIAL DETECTION
WITH MAGNETIC RELAXATION
Charalambos Kaittanis 1, 2, Saleh A. Naser 2, and J. Manuel Perez 1, 2, 3;
1
Nanoscience Technology Center, 2 Burnett College of Biomedical Sciences,
and 3Department of Chemistry, University of Central Florida, 12424 Research
Parkway, Suite 400, Orlando, Florida 32826, USA; [email protected].
311
Bacterial infections and intoxications still cause pathogenesis and morbidity across the
world. Acknowledging the associated societal impact and economic ramifications caused
by bacterial pathogenesis, we developed superparamagnetic iron oxide nanoparticles that
can rapidly and reliably detect a bacterial target in complex biological media at low target
concentrations. In our studies, we used Mycobacterium avium spp. paratuberculosis
294
(MAP) as our model microorganism. This bacterium (MAP) is the causative agent of
Johne’s disease in cattle, and has been associated with Crohn’s disease in humans. Using
our developed nanosensors, we were able to quantify MAP in milk and blood using
magnetic relaxation, within less than 45 minutes, due to the formation of nanoassemblies
between the bacteria and the nanoparticles. The MAP-induced nanoassmembly formation
was specific and not susceptible to interference caused by other bacteria. Lastly, various
samples and clinical samples were tested for MAP and the results were confirmed using
gold-standard methodology, though our nanoparticle-based method provided results
faster without the need of sample purification and amplification.
Poster Session P2
IRON OXIDE NANOPARTICLES PREPARED BY LASER PYROLISIS
FOR BIOMEDICAL APPLICATIONS
Virginia Bouzas and M. A. Garcia, Department Material Physics, University
Complutense at Madrid; [email protected]; R. Costo, M. P. Morales ands S.
Veintemillas-Verdaguer. Institute of Materials Science, CSIC, Madrid, Spain
312
Small magnetic particles have attracted considerable attention owing to their
technological and scientific importance. Iron oxide nanoparticles are one of the most
suitable tools in biomedical applications because of their utilities as drug delivering,
labelling bioelements and contrast agent for magnetic resonance imaging. To fulfil all
these objectives it is necessary to tailor precisely their magnetic properties. As the
features of the nanoparticles are strongly depending on their structure, size and shape, it
is needed production methods which allow controlling the structural parameters and
therefore, the magnetic ones. Among the different methods that can provide this kind of
nanoparticles, laser pyrolysis has the advantage to produce homogeneous and uniform
material in quantities fairly larger than other chemical methods, which requires a much
longer time to produce few milligrams and, results more expensive, too. Furthermore, this
technique produces highly pure particles, a key condition for their use in biomedicine in
order to avoid secondary effects. Here, we report on the preparation and magnetic
characterization of Fe oxide nanoparticles by laser pyrolysis and the relationship between
the preparation conditions and the magnetic response. Iron oxide nanoparticles were
prepared by pyrolysis laser using a continuous CO2 laser with Fe(Co)5, as precursor, and
a mixture of C2H4-Air, as flux carriers. With this conditions, Fe oxide nanoparticles
with size below 6 nm were obtained. Magnetization curves were measured at 10 K and
Room Temperature (i.e., above and below the blocking temperature) and the thermal
dependence of the magnetization was registered for a 1000 Oe field. All the samples
presented superparamagnetic behaviour at 300 K. Results show that the magnetic
properties are mainly related to the degree of crystallinity of the samples and less
sensitive to the particle size. It is concluded that the size and the main structural and
magnetic characteristics of the nanoparticles (coercive force, saturation magnetization,
anisotropy and blocking temperature) can be tuned in a wide range of values through the
synthesis conditions. Specially, the carrier flux is the most determining parameter.
295
Poster Session P2
BIONANOTECHNOLOGY AND BIOMOLECULES ON SURFACES
STUDIED BY DUAL POLARISATION INTERFOROMERY
Mark Gostock, Farfield Scientific Inc. Pittsburgh, PA 15201, USA;
[email protected]
313
Dual Polarisation Interferometry (DPI) is an analytical technique used to understand the
real-time structure and behaviour of a wide range of thin films and nanosurfaces through
quantitative measurement. DPI has been successful across a plethora of surface science
applications, including polymers, surfactants, fine chemicals and biomolecules. As an
interferometric technique, DPI has a wide dynamic range so can accommodate a broad
spectrum of solvents, such as DMSO and ethanol, and buffers and buffer additives. This
means that the DPI user can carry out experiments in the conditions of choice rather than
those dictated by the limitations of other techniques. The unique, absolute measurements
provided by DPI enables the researcher to question and understand thin films and
nanosurfaces and their interactions to an extent not previously available in a laboratorybased technique. This presentation introduces the biophysical and surface analysis
technique and discusses particular research areas as; nano-scale surface assembly,
polymer-surfactant interactions, quantification of protein interactions with liposome and
bilayer structures, biocompatibility studies, quantum dot and nanoparticle
characterisation and bionanotechnology; areas in which DPI has found particular success.
Poster Session P2
A ONE-STEP HOMOGENEOUS IMMUNOASSAY FOR CANCER
BIOMARKER DETECTION USING GOLD NANOPARTICLE PROBES
COUPLED WITH DYNAMIC LIGHT SCATTERING
Xiong Liu, Qiu Dai, Lauren Austin, Janelle Coutts, and Qun Huo* ;
NanoScience Technology Center, Department of Chemistry, Department of
Mechanical, Materials and Aerospace Engineering, University of Central
Florida, 12424 Research Parkway Suite 400, Orlando, Florida 32826;
314
Immunoassay development for cancer biomarker detection is important for prognosis of
cancer detection. Herein we report a novel method with reduced steps, easy-to-perform,
and higher sensitivity over bioanalytical ELISA methods for detection of free-prostate
specific antigen (f-PSA). Gold nanoparticle probes with primary antibodies conjugated
on surface were used as detecting probes, followed by detection of aggregation degree
with dynamic light scattering (DLS) measurements. In the presence of antigen f-PSA in
solution, the nanoparticles and nanorods aggregate together into pairs and oligomers
through the formation of a sandwich type antibody-antigen-antibody linkage. The relative
ratio of nanoparticle-nanorod pairs and oligomers versus individual nanoparticles was
quantitatively monitored by DLS measurement. A correlation can be established between
this relative ratio and the amount of antigen in solution. The light scattering intensity of
nanoparticles and nanoparticle oligomers is several orders of magnitude higher than
296
proteins and other typical molecules, making it possible to detect nanoparticle probes in
the low picomolar concentration range. f-PSA in the concentration range from 0.1 to 10
ng/mL was detected by this one-step and washing-free homogeneous immunoassay.
Poster Session P2
MORPHOLOGICAL GRADIENTS FOR CELL BIOLOGY
Christian Zink, Sara Morgenthaler and Nicholas D. Spencer, Laboratory for
Surface Science and Technology, ETH Zurich, Switzerland,
[email protected]
315
Surface roughness plays an important role in contact-related phenomena, such as
tribology or adhesion. Also, roughness plays a crucial role in the biological response to a
surface, i.e. cell adhesion, morphology, proliferation and differentiation. Two methods
were developed in our lab to create morphological gradients on a micrometer and on a
nanometer scale. Micro-featured gradients can be produced by using a two-step process :
First the aluminium substrates are sandblasted, followed by gradually polishing the rough
surface with a chemical polishing solution. Cell experiments with these gradients showed
that with increasing roughness rat calvarial osteoblast (RCO) have a significantly higher
proliferation rate. Nano-featured gradients can be fabricated by kinetically controlled
adsorption of negatively charged silica nanoparticles onto a positively charged,
polyethylene imine (PEI) coated silicon wafer. A subsequent sintering process results in a
firm attachment of the particles and the removal of the PEI. RCO cell experiments on
these gradients showed a significant decrease in proliferation with increasing particle
density on the surface. A combination of these two methods shall be used to create two
dimensional roughness gradients, varying in feature size along the two axes in order to
investigate the cellular response.
Poster Session P2
SELECTED CELL PATTERNING USING COLLOIDAL LITHOGRAPHY
Jau-Ye Shiu, Chiung Wen Kuo and Peilin Chen, Research Center for
Applied Sciences, Academia Sinica, Taipei 115, Taiwan;
316
The understandings of the cell-substrate interactions are important in many aspects
including biocompatibility, cell culture, cell spreading and tissue engineering. It is
recognized that the adhesion of cells on materials depends on surface characteristics such
as hydrophobicity, surface charge, surface chemistry and roughness. In this paper, we
will discuss the cell adhesion on the nanostructured surfaces. Using a combination of
nanosphere lithography and nanoimprint lithography, we were able to create pillar like
nanostructures on various polymer surfaces, such as Teflon and polystyrene, without
changing the surface chemistry of these polymers. In our approach, the nanosphere
lithography was used to create close-packed well-ordered patterns. The size of the
polymeric colloidal nanoparticles was trimmed by oxygen plasma treatment and followed
by metal deposition. After the lift-off and deep etching process, nanohole arrays with
desired depth could be obtained, which were then used the stamp in the nanoimprint
process. By controlling the oxygen plasma etching time, the separation distance and the
297
diameter of the holes could be adjusted, which in turn produced various types of
polymeric nanopillars with surface water contact angle ranging from 120 degree to 160
degree. When these nanostructured surfaces were used to culture HeLa and 3T3 cells. It
was found that both cells did not adhere on the flat area. However, the adhesion of 3T3
cell on the area with nanopillars increased with their surface water contact angle. Such
nanostructured materials could be used as new materials for tissue engineering.
Poster Session P2
TAILORING THE PHARMACOKINETIC BEHAVIOUR OF POLY-LLYSINE DENDRIMERS FOR THEIR USE AS CONTROLLED DRUG
DELIVERY VEHICLES
Ben J. Boyd1, Lisa Kaminskas1, Brian Kelly2, Christopher J. H. Porter1;
1
Monash Institute Pharmaceutical Science, Monash University, Parkville,
Australia; 2Starpharma Pty. Ltd., Level 6, Baker Heart Research Building,
Commercial Road, Melbourne, VIC, 3004, Australia;
[email protected]
317
Dendrimers are large polymeric scaffolds constructed from multivalent monomeric units,
for which the size, geometry, surface charge, and surface chemistry can all be varied.
They display both particle-like and macromolecule-like behaviours, and are increasingly
of interest as drug delivery systems, although very little is currently known about their
pharmacokinetic and biodistribution behaviour. We have been investigating the potential
of PEGylated poly-L-lysine (PLL) dendrimers for drug delivery to tumors via the
enhanced permeation and retention effect. In the first phase of these studies, we have
determined the pharmacokinetic parameters for these dendrimers with varying PEG
molecular weight and dendrimer size in rats. The plasma half-life of the fully PEGylated
dendrimers has been shown to vary widely with structure, and is primarily dependent on
renal excretion; for example a fully PEGylated 68 kDa dendrimer displayed a plasma half
life of approximately 75 hours, compared to < 1 hr for a 6 kDa fully PEGylated
dendrimer. Interestingly the shape of the dendrimer (symmetric vs asymmetric) also had
an influence the pharmacokinetic behaviour. Substituting a proportion of the PEG groups
with methotrexate (MTX), a model anticancer drug, resulted in a shorter half-life
compared to the fully PEGylated equivalent dendrimers, however half lives of up to 2
days were still achieved (with a 48 kDa, 50% MTX, 50% PEG dendrimer). Finally, the
fate of the dendrimer core after drug liberation is also important from a toxicological and
regulatory perspective. We have previously shown that uncapped (100% free surface
amine) PLL dendrimers are rapidly metabolised in vivo to free lysine. Dendrimers with
50% PEG coverage, but with 50% free surface amines, were cleared from plasma more
rapidly than equivalent fully PEGylated dendrimers. Using size exclusion
chromatography, we have shown that the 50% uncapped dendrimers are also metabolised
to free lysine in vivo. Interestingly, we have further evidence that small 50%PEG 50%
MTX dendrimers are also metabolised but that increasing dendrimer size inhibits the
action of proteases in metabolising the dendrimer constructs. In summary, our
experimental program has yielded important insights into the behaviour of these systems
in vivo and will inform our rational choice of structures for progress into tumor
deposition and efficacy studies.
298
Poster Session P2
POLYION COMPLEX MICELLES FOR EX VIVO DENDRITIC CELL
THERAPY: FORMATION AND CHARACTERIZATION
Ariane Boudiera, Corine Gérardina, Anne Aubert-Pouëssela, Pascale LouisPlenceb, Christian Jorgensenb, Jean-Marie Devoissellea, Sylvie Bégua, aInstitut
Charles Gerhardt Montpellier, UMR 5253 CNRS UM2 ENSCM UM1,
b
Inserm U 844, Montpellier, France; [email protected],
[email protected]
318
Dendritic cells are professional antigen presentating cells. They are able to initiate and to
control antigen-specific immune responses, making them attractive for new therapeutic
approaches of tumorous or autoimmune pathologies. The application of vectors in
dendritic cell therapy implies the use of biocompatible pH-sensitive nanoparticles able to
adapt to the cell physiology. The aim of our study is then to evaluate the use of pHsensitive double-hydrophilic block copolymer (DHBC) micelles as drug vectors for ex
vivo dendritic cell therapy. Polyion complex micelles, constituted of a polymethacrylic
acid-b-polyethylene oxide DHBC and a poly-L-lysine homopolymer, were prepared by
mixing the two polymer aqueous solutions at a charge ratio (lysine/acrylate) of 1. The
micelles are characterized by dynamic light scattering and electrophoretic measurements,
their behavior is studied as a function of environmental parameters such as the pH and
the ionic strength. Circular dichroism and fluorescence techniques (pyrene
incorporation) were also used to investigate the core organisation. Finally, the
endocytosis of micelles (formulated with FITC labelled poly-L-lysine) by murine bone
marrow-derived dendritic cells was observed by fluorescence microscopy. The results are
the following: micelles have a hydrodynamic diameter of about 30 nm with a narrow size
distribution and a zeta potential close to zero. The circular dichroism analysis shows that
micelle formation is accompanied by a major change of poly-L-lysine conformation,
from a random coil to an alpha helix. This is concomitent with changes in pyrene spectra,
which reveal the presence of hydrophobic zones. A plateau of stability is also observed in
a pH domain between the pKs of the polyacid and polybase; this implies that micellar
structures are stable at physiological pH and disassemble in acidic conditions. Moreover, the
colloids are not affected by an increase of the ionic strength, showing their stability in
physiological conditions. Lastly, an intracellular distribution of the micelles in dendritic
cells was observed by fluorescence microscopy. In conclusion, the present pH-sensitive
micelles, exhibiting a peculiar core nanostructure and a good stability in physiological
conditions, are potential candidates for a use as drug vectors in ex vivo dendritic cell
therapy.
Poster Session P2
NOVEL STIMULI-RESPONSIVE MICROGEL SYSTEMS WITH
AMPHOTERIC BEHAVIOUR FOR ENZYME IMMOBILIZATION
Andrij Pich, Hans-Juergen P. Adler and Susann Schachschal, Technische
Universität Dresden, Mommsenstr. 4, 01062 Dresden, Germany;
[email protected]
319
299
Microgels that recognize and respond to environmental stimuli such as temperature, pH,
light, ionic strength as well as electric field are of great note. These materials are suitable
protein carriers and are also used in biosensors, tissue engineering, actuators and basic
biological research. pH-responsive microgels containing positive and negative charges
within their structure are called polyampholytes. Much attention has been paid to the
synthesis of colloidal polyampholytes due to their interesting solution properties and
consequently their multitude of potential applications. The aim of this work is the
development of a novel carrier system which allows the innovative immobilization of
enzymes. The synthesized microgel systems should exhibit a sufficient porosity for mass
transport as well as a large reactive surface. The latter can be achieved by incorporation
of reactive anchor groups in the microgel structure and by controlling the particle size.
Furthermore temperature- and pH-sensitive properties of such microgel systems are of
vital importance to protect the immobilized enzymes. The synthesis of polyampholyte
microgels, which are based on the thermo-sensitive monomer N-Vinylcaprolactam
(VCL), occurred via a two-step-process. Initially the synthesis of microgel is carried out
by surfactant-free emulsion polymerization of N-Vinylcaprolactam and the co-monomers
Dimethyl itaconate (IADME) and Vinylimidazole (VIm). The both last-mentioned
monomers are required to generate pH-sensitive behaviour. The microgels obtained after
the first step were analyzed in detail concerning their particle size, particle size
distribution, morphology, colloidal, and sensitive properties. It could be demonstrated,
that these microgels are temperature-sensitive due to the presence of N-Vinylcaprolactam
in the copolymer structure. This sensitivity causes a collapse of particle size above the
volume phase transition temperature (32°C) of the microgels to nearly 25% of the
original hydrodynamic radius. Particle size and swelling degree can be controlled
particularly by the VIm-content. Depending on the VIm-content particle size of microgels
changes between 500 nm and 800 nm in radius. But also other reaction parameter, such
as temperature, IADME-content etc. can affect the properties of PVCL/IADME/VImmicrogels. Due to the presence of VIm the microgels are pH-sensitive and reach a
maximum of particle size at pH 4. Due to a subsequent alkali hydrolysis of IADME units
of the PVCL/IADME/VIm-microgel carboxylic groups in the form of Itaconic acid (IA)
can be generated within microgel network during second step providing an amphoteric
behaviour of these particles. The PVCL/IA/VIm-microgel particles are colloidally stable
and do not form aggregates over the whole pH range. In this way amphoteric microgels
could be synthesized successfully with a particle swelling between pH 3 and 5 as well as
pH 7 and 9. This pH - sensitive behaviour results in a variation of temperature sensitivity
of non-hydrolyzed microgel. Both, pH and temperature sensitivity of PVCL/IA/VImmicrogels are of great advantage for the following enzyme immobilization which will be
realized in alkaline media. Furthermore the optimal activity of used enzymes is pH 4.
Poster Session P2
SYNTHESIS AND CHARACTERIZATION OF SILICA
MICROCAPSULES CONTAINING MATERIALS OF DIFFERENT
VISCOSITY
Idurre Kaltzakorta and Edurne Erkizia, Labein-Tecnalia, Calle Geldo,
320
300
Edificio 700, ParqueTecnológico de Bizkaia, Derio 48160, BIZKAIASPAIN; [email protected]
Silica microcapsules containing organic compounds of different viscosities have been
synthesized following a core/shell based in situ microencapsulation method via a sol-gel
route. The viscosity of the organic compounds encapsulated ranged between 3 cP to 6000
cP and in all cases, even in the highest viscosity one, microcapsules containing the
organic material have been obtained. Furthermore, it has been determined that, by
playing with the type and viscosity of the encapsulated material, the shell morphology
and thickness can be varied.
Poster Session P2
THE SYNTHESIS AND CHARACTERIZATION OF DYEENCAPSULATED CALCIUM PHOSPHATE NANOPARTICLES
Thomas T. Morgan, Erhan Altinoglu, and James H. Adair. Departments of
Chemistry and Materials Science and Engineering, The Pennsylvania State
University, University Park, PA, 16802 USA; [email protected].
321
Encapsulation of fluorescent dyes and other organic molecules in nanoparticulate systems
is of significant importance in the fields of drug delivery and biological imaging. To this
end, a general scheme has been developed to encapsulate small organic molecules in 2030 nm calcium phosphate nanoparticles for use as bioimaging or drug delivery agents.
The particles were precipitated in the presence of a variety of organic fluorescent dye
molecules that span the visible spectrum and were prepared with several surface
functional groups. Zeta potential measurements were used to confirm carboxy-, amino-,
and methyl-PEG functionality. Furthermore, solution phase characterization was used to
determine the dissolution behavior of the particles across a range of pH values as well as
the fluorescent properties of the encapsulated dyes. A hybrid size-exclusion/van der
Waals HPLC system was utilized to wash the particles while mainting colloidal
dispersion.
Poster Session P2
FLUORESCENCE BASED LIPOSOME ENCAPSULATION STUDIES
Joseph E. Reiner, Andreas Jahn, Michael Gaitan, Semiconductor Electronics
Division, EEEL, NIST, Gaithersburg, MD 20899, USA, Wyatt N. Vreeland
and Laurie Locascio, Biochemical Science Division, CSTL, NIST,
Gaithersburg, MD 20899, USA; [email protected]
322
Liposomes are self-assembled spherical vesicles comprised of a lipid bilayer membrane.
Nanometer-sized liposomes have demonstrated potential for drug delivery applications.
For liposomes to be useful for these applications, one must control the size and dosage of
molecules contained within them. We report on a combination of fluorescence methods
for studying these properties. We form our liposomes using flow-focusing methods in a
microfluidic device. This technique leads to a collection of liposomes having a narrow
size distribution without the need for post processing methods (i.e., extrusion). We use
301
sulforhodamine B (SRB), a water-soluble dye, to quantify the encapsulation efficiency
and long-term stability of our liposome samples. An inverted microscope in a confocal
detection arrangement measures the fluorescence from a sample of liposomes. The
fluorescence signal is recorded and processed to arrive at the photon counting histogram
(PCH) and the autocorrelation function (ACF). The ACF is used to extract the amount of
background dye present in each sample. The first two moments of the fluorescence
signal are calculated from the PCH. These moments, along with the background dye
concentration, are combined to provide a measure of the average brightness of a liposome
sample. By comparing this brightness with a sample of free SRB in solution, we are able
to estimate the number of SRB molecules contained within the liposomes and therefore,
estimate the encapsulation efficiency. Other techniques for estimating the encapsulation
efficiency rely on destroying a portion of liposome sample (i.e. liposome lysing);
however, from a processing standpoint it is preferable to characterize liposome samples
in a non-destructive manner (fluorescence fluctuation analysis). In addition, a nondestructive fluorescence analysis could be more easily incorporated into a microfluidic
structure where liposome formation, analysis, and modification could all be performed in
real time. We present results from several different samples of liposomes. We show that
our liposomes contain the SRB molecules for extended periods (~ 1 year) and that under
different flow conditions in the microfluidic channel, we can also control the amount of
dye encapsulated for the same initial loading dye concentration.
Poster Session P2
FUNCIONALIZED POLYUREA NANOCAPSULES VIA REACTION AT
INTERFACE OF MINIEMULSION DROPLETS
E.-M. Rosenbauer, A. Musyanovych, K. Landfester, Department of Organic
Chemistry III – Macromolecular Chemistry and Organic Materials, University
of Ulm, 89069 Ulm, Germany; [email protected]
323
The potential advantage of functionalized polyurea nanocapsules with an aqueous core is
of high interest in biomedical applications since they can be used as specific carriers of
water soluble drugs to the cells. The polymeric capsules give the possibility to protect
the encapsulated material from the influence of the environment. The miniemulsion
technique is a convenient and powerful tool for the preparation of the polymeric capsules
in a size range from 100 to 500 nm. The miniemulsion technique is based on the
formation of small and stable nanodroplets dispersed in a continuous phase. High
stability of these droplets offers the opportunity to perform the reaction within the
droplets or at their interface. Polyurea nanocapsules were prepared in inverse (water-inoil) miniemulsion via interfacial polyaddition reaction between 1,6hexamethylenediamine (dissolved in water phase) and toluene 2,4-diisocyanate (dropwisely added into the continuous phase). The resulting particles have a “core-shell”
structure, consisting of an aqueous cavity surrounded by a polymeric membrane. By
using a new surfactant containing primary amino group it participates in the reaction,
resulting in polymeric shell with grafted chains of surfactant. By the variation of several
reaction parameters such as monomer concentration, surfactant concentration, and the
dispersed to continuous phase ratio, the shell thickness can be adjusted between 13 and
25 nm. The capsules size and polydispersity size were determined by dynamic light
302
scattering (DLS), the morphology and structure of the capsules were confirmed by
transmission electron microscopy (TEM). The capsules containing fluorescence dye as a
model for hydrophilic drug were additionally analyzed by fluorescence spectrometer in
order to control semi- or impermeability of the polymeric membrane.
303
304
Index of Speakers/Presenters
(Alphabetically with Paper Number and Session Number)
Abdel-Fattah, Amr – 191 (C2)
Abubakar, Mo – 133 (P1)
Adair, James – 177 (G2)
Adschiri, Tadafumi – 16 (A2)
Africk, Steven – 134 (P1)
Akarachalanon, Pilaslak – 309 (P2)
Almeida, José – 151 (P1)
Altinoglu, Erhan – 146 (P1)
Ammar, Souad – 103 (F2)
Anal, Anil – 184 (B2)
Arroyo-Ramírez, Lisandra - 109
(P1)
Bakhbakhi, Yousef – 223 (A5)
Baldwin, Richard – 417 (E4)
Ballinger, Clinton – 166 (A4)
Bell, Nelson – 119 (P1)
Bellomunno, Carla – 205 (D2)
Belosludov, Rodion – 167 (A4)
Benicewicz, Brian – 88 (J1), 156
(P1)
Bera, Debasis – 279 (P2), 328 (A6)
Berger, Shlomo – 247 (C3)
Bergström, Lennart – 47 (F1)
Berkland, Cory – 186 (B2)
Berret, Jean-François – 105 (F2),
135 (P1)
Biggs, Simon – 90 (J1)
Binks, Bernard – 212 (F3)
Böhmer, Marcel – 21 (B1)
Bon, Stefan – 214 (F3)
Bonroy, Kristien – 175 (G2)
Bourgeat-Lami, Elodie – 218 (F3),
303 (P2)
Bouzas, Virginia – 107 (F2)
Bouzas, Virginia – 312 (P2)
Boyd, Ben – 261 (L1), 317 (P2)
Boyen, Hans-Gerd – 210 (E2)
Braun, Paul – 189 (C2)
Brayner, Roberta – 330 (A6)
Bronstein, Lyudmila – 101 (F2)
Brotzman, Richard – 13 (A2)
Bumajdad, Ali – 37 (D1)
Burkhard, Peter – 395 (H3)
Burnett, Daniel – 136, 137 (P1);
282 (P2)
Caldwell, Marissa l – 120 (P1)
Carpenter, Everett – 352 (M1)
Carr, Bob – 34 (D1)
Celis, Maria-T. – 361 (D3)
Chakrapani, Aravind – 154 (P1)
Champion, Julie – 188 (B2)
Chastek, Thuy – 155 (P1), 203 (D2)
Chen, Peilin – 46 (E1)
Chen, Yit-Tsong – 68 (G1)
Chen, Youcun 121 (P1)
Chernyshova, Irina – 139 (P1)
Choi, Hee Jung – 157 (P1)
Choi, Sung-Min – 4 (A1)
Chow, Gan Moog – 178 (G2)
Choy, Wallace C.H. – 366 (E3)
Cinque, Leonardo – 360 (D3)
Clavel, Guylhaine – 353 (M1)
Clemans, Daniel – 97 (K1)
Cliffel, David – 253 (J2)
Coleman, Karl – 5 (A1)
Cölfen, Helmut – 81 (I1), 196 (D2)
Colvin, Vicki – 165 (Plenary 2)
Compagnini, Giuseppe – 7 (A1),
419 (E4)
Cook, Ronald – 254 (J2)
305
Speakers/Presenters Index (continued)
Coradin, Thibaud – 349 (B3)
Cywinski, Piotr – 147 (P1), 333
(G4)
Dai, Qiu – 87 (J1), 158 (P1)
Daniels, Eric – 187 (B2)
de Kruif, Cornelis – 346 (B3)
Demirors, Ahmet Faik – 381 (A7)
Deng, Zhaoxiang – 248 (C3)
Desbiens, Jessie – 295 (P2)
Díaz, David – 173 (A4)
Dietsch, Hervé – 83 (I1)
Do, Trong-On – 291, 292 (P2)
Dobrovolskaia, Marina – 98 (K1)
Dong, Yao-Da – 152 (P1)
Dormidontova, Elena – 236 (H2)
Dovgolevsky, Ekaterina 288 (P2)
Duan, Hongwei – 171 (A4)
Duke, Steve – 224 (A5)
Dukhin, Andrei – 35 (D1)
Durant, Yvon – 58 (A3)
Dutta, Joydeep – 172 (A4), 243
(C3)
Dutta, Prabir – 94 (K1)
Ebina, Takeo – 268 (F4)
Edwin, Nadia – 140 (P1)
Ennen, Inga – 358 (D3)
Erkizia, Edurne – 320 (P2)
Ethirajan, Anitha – 373 (F5)
Fang, Jiyu – 29 (C1)
Feldmann, Claus – 379 (A7)
Feng, Si-Shen – 70 (H1)
Fiegel, Jennifer – 239 (H2)
Fiévet, Fernand – 169 (A4)
Ford, Warren – 56 (A3)
Foulger, Stephen – 192 (C2)
Frank, Hendrik – 294 (P2)
Frazier, Rachel – 18 (B1)
Frelichowska, Justyna – 71 (H1)
Fujioka, Kouki – 308 (P2)
306
Furumi, Seiichi – 401 (C4)
Ganachaud, François – 221 (A5)
Gao, Xiaohu – 180 (G2)
Garcia, Miguel Angel – 422 (F6)
Gathen, Miriam – 343 (B3)
Gauffre, Fabienne – 331 (A6)
Gerardin, Corine – 326 (A6), 318
(P2)
Gesquiere, Andre – 402 (C4)
Geutjes, Paul P.J. – 260 (L1)
Giannelis, Emmanuel – 262 (F4)
Giersig, Michael – 174 (G2)
Giraud, Sophie – 9 (A1)
Gish, Douglas A. - 110 (P1)
Goepfert, Christophe – 99 (K1)
Goernitz, Eckhard – 195 (C2), 272,
273 (P2)
Golan, Yuval – 84 (I1)
Gostock, Mark – 141 (P1), 313 (P2)
Gower, Laurie – 342 (B3)
Gun’ko, Yuri – 383 (A7)
Gupta, Ram – 238 (H2)
Guterres, Sílvia – 22 (B1)
Haas, Heinrich – 399 (H3)
Hadley, Judith – 204 (D2)
Hammarberg, Elin – 111 (P1)
Harada, Takuya – 26 (C1)
Hayashi, Yasuhiko – 416 (E4)
Hedderich, Regine – 112 (P1)
Herlin-Boime, Nathalie – 213 (F3)
Hertel, Tobias – 332 (G4)
Hino, Tomoaki – 392 (H3)
Hjelm, Rex – 388 (A8)
Hoerr, Robert – 92 (J1)
Hofmann, Heinrich – 249 (J2)
Holt, Benjamin – 329 (A6)
Hong, L. – 350 (B3)
Hong, Liang – 423 (F6)
Hong, Sung Chul – 159 (P1)
Horozov, Tommy – 421 (F6)
Hsu, Lien-chung – 44 (E1)
Hu, Michael Z. – 264 (F4)
Hu, Zheng – 255 (J2)
Huber, Dale – 106 (F2)
Huo, Qun – 181 (G2)
Hupfeld, Stefan – 258 (L1)
Hurst, Kendall – 287 (P2)
Hwang, Kuo Chu – 382 (A7)
Hyeon, Taeghwan – 66 (G1)
Jada, Amane – 82 (I1)
Jahn, Andreas – 257 (L1)
Jaksch, Stefan – 3 (A1)
Jang, Du-Jeon – 380 (A7)
Jia, Li – 31 (C1)
Jiang, Long – 339 (G4)
Jiang, Peng – 183 (B2), 246 (C3)
Jiménez, Isaac Ojea – 280 (P2)
Jin, Song – 265 (F4)
Jones, Paul – 364 (D3)
Juillerat-Jeanneret, Lucienne –
411 (J3)
Jung, Dylan – 113 (P1)
Kaittanis, Charalambos – 311 (P2)
Kalyuzhny, Gregory – 122 (P1)
Kamiya, Hidehiro – 89 (J1)
Kanga, Yao – 199 (D2)
Karim, Alamgir - 25 (C1)
Karim, Mohammad Rezaul – 275
(P2)
Kasyutich, Oksana – 190 (C2)
Kauppinen, Esko – 2 (A1)
Kaur, Jasmeet – 277 (P2)
Kawaguchi, Haruma – 387 (A8)
Kawazoe, Tadashi – 206 (E2)
Kemp, Neil – 413 (E4)
Khondaker, Saiful – 418 (E4)
Kim, Jung Hyun – 226 (A5)
Kim, Min Sung – 276 (P2)
Ko, Sungho – 148 (P1)
Koh, Seong Jin – 208 (E2)
Koo, Horng-Show (Frank) – 378 (F5)
Korgel, Brian – 367 (E3)
Kosc, Tanya – 41 (E1)
Kotov, Nicholas – 207 (E2)
Kovtyukhova, Nina – 370 (E3)
Krauss, Todd – 216 (F3)
Kremser, Gabriele – 123 (P1)
Kristiansen, Helge – 197 (D2)
Kumar, Jitendra – 385 (A7)
Kumar, Nanjundan Ashok – 160
(P1)
Kumar, Sonia – 149 (P1)
Kunitake, Masashi – 57 (A3)
Kuo, Chiung Wen – 316 (P2)
Lacerda, Silvia – 179 (G2)
Lähde, Anna – 306 (P2)
Laine, Richard – 40 (E1)
Lakatos, Mathias – 285 (P2)
Lammel, Andreas – 299 (P2)
Landfester, Katharina – 55 (A3)
Lau, Kenneth K.S. – 410 (J3)
Leblanc, Roger – 325 (A6)
Lee, Hyun Woo – 274 (P2)
Lee, Jung Min – 161 (P1)
Lee, Sun Jong – 300 (P2)
Leubner, Ingo – 220 (A5), 307 (P2)
Leung, Tong – 351 (M1)
Li, Chen-Zhong – 355 (M1)
Li, Yu – 162 (P1)
Lich, Ben – 357 (D3)
Lim, Yong Taik – 145 (P1)
Lin, Victor S.-Y. – 76 (H1)
Liu, Xiong – 314 (P2), 386 (A7)
Liu, Yonglin – 384 (A7)
Liz-Marzán, Luis – 78 (I1)
López, Cefe – 193 (C2)
307
Louis, Cédric – 406 (J3)
Lowe, Tao – 77 (H1)
Lu, Wensheng – 286 (P2)
Lu, Yunfeng – 215 (F3)
Luo, Yingwu – 20 (B1)
Manabe, Noriyoshi – 310 (P2)
Mangalaraja, R.V. – 124 (P1); 301,
302 (P2)
Mann, J. Adin, Jr., - 51 (F1)
Manna, Liberato – 225 (A5)
Markovich,Gil – 230 (G3), 376 (F5)
Markowitz, Michael – 374 (F5)
Martiradonna, Luigi – 368 (E3)
Martucci, Alessandro – 118 (P1),
371 (E3)
Masuda, Yoshitake – 125 (P1)
Matsuo, Masaru – 102 (F2)
Mattoussi, Hedi – 65 (G1)
McMahon, Matthew – 38 (D1)
Meier, Wolfgang – 256 (L1)
Menéndez-Flores, Victor – 114
(P1)
Menéndez-Manjón, Ana – 8 (A1)
Millot, Nadine – 126 (P1)
Mills, G. Jimmy – 49 (F1)
Mishra, Sanjay – 293 (P2)
Morfesis, Ana – 138 (P1)
Morgan, Thomas – 321 (P2)
Morrison, Ian – 32 (D1)
Mouaziz, Hanna – 75 (H1), 153 (P1
Mozetic, Miran – 36 (D1)
Mukherjee, Arup – 39 (D1)
Mukhopadhyay, Gautam – 363
(D3)
Mukhopadhyay, Pagati – 271 (P2)
Murray, Christopher – 1 (Plenary
1)
Naciri, Jawad – 232 (G3)
Nakai, Kei – 237 (H2)
308
Narkis, Moshe – 59 (A3)
Narkis, Nava – 95 (K1)
Nath, Sudip – 150 (P1)
Nativo, Paola – 96 (K1)
Niederberger, Markus – 10 (A2)
Nisisako, Takasi – 79 (I1)
Nitin, Nitin – 64 (G1)
Nobbmann, Ulf – 142 (P1)
Nojeh, Alireza – 414 (E4)
Nur, Hani – 296, 297 (P2), 359 (D3)
Osawa, Eiji – 6 (A1)
Paciotti, Giulio – 235 (H2)
Paiphansiri, Umaporn – 344 (B3)
Panchapakesan, Balaji – 241 (H2)
Panda, Priyadarshi – 115 (P1)
Papa, Anne-Laure – 336 (G4)
Paquet, Chantal – 63 (G1)
Parak, Wolfgang – 229 (G3)
Park, Dong-June – 128 (P1)
Park, Jungjin – 409 (J3)
Pein, Andreas – 278 (P2)
Pelton, Robert – 176 (G2)
Pereira, Clara – 163 (P1)
Perez, Alain – 43 (E1)
Perez, J. Manuel – 72 (H1)
Pietryga, Jeffrey – 415 (E4)
Pilotek, Steffen – 250 (J2)
Pinna, Nicola – 127 (P1), 168 (A4),
228 (G3)
Piquemal, Jean-Yves – 15 (A2)
Pishko, Michael – 17 (B1)
Poggi, Mark – 198 (D2)
Pohlmann, Adriana – 396 (H3)
Porter, Marc – 67 (G1)
Preece, Jon – 405 (J3)
Prevot, Vanessa – 85 (I1), 129 (P1)
Qiu, Zhiming – 263 (F4)
Ragupathy, Lakshminarayanan –
327 (A6)
Rahme, Kamil – 412 (J3)
Raula, Janne – 240 (H2)
Ravaine, Serge – 404 (C4); 407
(J3)
Redford, Keith – 298 (P2)
Redón, Rocío - 130 (P1)
Reiner, Joseph – 322 (P2)
Richert, Clemens – 27 (C1)
Roberts, Christopher – 222 (A5)
Rosenbauer, Eva-Maria – 323 (P2)
Rosenman, Gil – 251 (J2)
Rosenthal, Sandra – 365 (E3)
Rossini, G. – 341 (B3)
Rossmanith, Renate – 116 (P1)
Rotello, Vincent – 217 (F3), 227
(G3)
Rungta, Parul – 164 (P1)
Ruppert, Marcel – 304 (P2)
Salonen, Jarno – 398 (H3)
Santra, Swadeshmukul – 338 (G4)
Sarrazin, Pierre – 425 (F6)
Satoh, Toshifumi - 19 (B1)
Saunders, Steven – 117 (P1)
Sawada, Tsutomu – 245 (C3)
Schachschal, Susann – 319 (P2)
Scheffold, Frank – 200 (D2)
Scheibel, Thomas – 340 (B3)
Schoenfeld, Winston – 403 (C4)
Schumacher, Iris – 393 (H3)
Sentein, Carole – 14 (A2)
Seyrek, Emek - 24 (B1)
Shahbazyan, Tigran – 335 (G4)
Shastri, V. Prasad – 91 (J1)
Sicard, Lorette – 11 (A2)
Sigmund, Wolfgang – 394 (H3)
Singhal, Amit – 50 (F1)
Skandan, Ganesh – 219 (A5)
Smirnov, Alex – 201 (D2)
Sokolov, Igor – 182 (B2)
Song, Qing – 170 (A4)
Spori, Doris – 270 (P2)
Srivastava, S K – 284 (P2)
Steinhart, Martin – 372 (F5)
Stellacci, Francesco – 61 (G1)
Steller, Laura – 209 (E2)
Stiefelhagen, Johan – 281 (P2)
Su, Ming – 375 (F5)
Sun, Kang – 62 (G1)
Sunkara, Mahendra – 108 (F2)
Sykora, Milan – 362 (D3)
Tabaković, Amra – 143 (P1)
Takahara, Atsushi – 86 (J1)
Takeda, Yoshihiko – 400 (C4)
Tamburri, Emanuela – 269 (P2)
Tamburri, Emanuela – 30 (C1)
Teh, Geok Bee – 289 (P2)
Teh, Geok Bee – 347 (M1)
ten Elshof, Johan E. – 48 (F1)
Terrones, Mauricio – 377 (F5)
Texter, John – 391 (A8)
Thies, Curt – 345 (B3)
Thompson, David – 231 (G3), 259
(L1)
Thompson, David –
Tilley, Richard – 80 (I1)
Tok, Ai Tee – 202 (D2)
Toprak, Muhammet – 420 (F6)
Trau, Dieter – 23 (B1)
Tripp, Carl – 252 (J2)
Tsoukalas, Dimitris – 211 (E2)
Tung, Hsien-Hsin – 390 (A8)
Türke, Alexander – 290 (P2)
Ulijn, Rein – 74 (H1)
Valle-Orta, Maiby – 305 (P2)
Van Suetendael, Nancy – 45 (E1)
Vanfleet, Richard – 356 (D3)
Vazquez-Olmos, America – 131
(P1)
309
Velikov, Krassimir – 73 (H1)
Vezenov, Dmitri 60 (A3)
Wang, Chi-Hwa – 185 (B2)
Wang, Howard – 266 (F4)
Wang, Huiliang – 389 (A8)
Wang, Jian-Ping – 354 (M1)
Watanabe, Shigeru – 194 (C2)
Weber, Achim – 337 (G4)
Wei, Alexander – 233 (G3)
Wei, Xian-Wen – 242 (H2)
Weiss, Clemens – 397 (H3)
Williams, Yvonne – 100 (K1)
Winnik, Mitchell – 104 (F2)
Wong, Stanislaus – 424 (F6)
Woo, Hyun-Ryool – 42 (E1)
Wu, Aiguo – 348 (B3)
Wu, Yu-Jui – 283 (P2)
Xu, Chunye – 369 (E3)
Xu, Ren – 33 (D1)
Xu, Zheng – 132 (P1)
Xuyen, Nguyen Thi – 93 (J1)
Yamanoi, Yoshinori – 408 (J3)
Yang, Hong – 52 (F1)
Yang, Huaming – 54 (F1)
Yin, Yadong – 244 (C3)
Yu, Kui – 334 (G4)
Yun, Wan Soo – 69 (G1)
Zanetti-Ramos, Betina Giehl – 144
(P1)
Zhai, Lei – 267 (F4)
Zheng, Ying – 12 (A2)
Zhong, Chuan-Jian – 53 (F1)
Zink, Christian – 315 (P2)
Zou, Shengli – 234 (G3)
Zubarev, Eugene – 28 (C1)
310
Pre-Registered Conferee List
Amr Abdel-Fattah
Los Alamos National Laboratory
PO Box 1663, Mail Stop J514
Los Alamos, NM 87545, USA
[email protected]
José Filipe Almeida
University of Coimbra
Rua Silvio Lima
3030-790, Coimbra, Portugal
[email protected]
Mo Abubakar
IMERYS Minerals Ltd
Par Moor Centre
Par Moor Road
Par, PL24 2SQ, Cornwall, United
Kingdom
[email protected]
Erhan Altinoglu
Pennsylvania State University
221 Materials Research Laboratory
University Park, PA 16802, USA
[email protected]
James Adair
Particulate Materials Center
249 Materials Research Laboratory
[email protected]
Tadafumi Adschiri
AIMR Tohoku University
2-1-1 Katahira, Aoba
Sendai, 980-8577, Japan
[email protected]
Steven Africk
Massachusetts Institute of
Technology
Prodyne Corp
30 Fenwick Road
Waban, MA 02468, USA
[email protected]
Pilaslak Akarachalanon
Ministry of Public Health
Department of Medical Science
88/7 Tiwanon Road, Taradkwan
11000, Nonthaburi, Thailand
[email protected]
Sarjak Amin
Eastern Michigan University
Coatings Research Institute
430 West Forest Avenue
Ypsilanti, MI 48197, USA
[email protected]
Souad Ammar
Université Paris Diderot, ITODYS
1, Rue Guy de La Brosse
75251, Paris cedex 05, France
[email protected]
Anil Kumar Anal
Living Cell Technologies (Global) Ltd
PO Box 23566 Hunters Corner
Papatoetoe, 2025, Auckland, New
Zealand
[email protected]
Chris Anderson
Polysciences, Inc
400 Valley Road
Warrington, PA 18976, USA
[email protected]
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Preregistered Conferfee List (continued)
Jefferey Anderson
Nanoscience Technology Center
[email protected]
Lisandra Arroyo-Ramírez
University of Puerto Rico, Rio
Piedras Campus
PO Box 23346
San Juan, PR 00931-3346, USA
[email protected]
Julien Aubry
Institut Charles Gerhardt UMR5253
ENSCM
8 rue de l’école normale
34269, Montpellier cedex, France
[email protected]
Frans Baeten
Ferro Electronic Materials Systems
Frontstraat 2
5401LW, Uden, Netherlands
[email protected]
Jeff Baker
TSI Incorporated
500 Cardigan Road
Shoreview, MN 55126, USA
[email protected]
Yousef Bakhbakhi
King Saud University
Chemical Engineering Dept
College of Engineering, PO Box 800
Riyadh, 11421, Saudi Arabia
[email protected]
Richard Baldwin
NanoComposix
4878 Ronson Court, Suite K
San Diego, CA 92111, USA
[email protected]
312
Clinton Ballinger
Evident Technologies, Inc
216 River Street, Suite 200
Troy, NY 12180, USA
[email protected]
J. R. Barrett
2125 28th St, SW, Suite 1
Allentown, PA 18103, USA
[email protected]
Nelson Bell
Sandia National Laboratory
PO Box 5800-1411
Albuquerque, NM 87185, USA
[email protected]
Carla Bellomunno
CNR-IENI sect Milan
via R. Cozzi 53
20125, Milan, Italy
[email protected]
Rodion Belosludov
Institute for Materials Research
Tohoku University
Katahira 2-1-1, Aoba-ku
Sendai, 980-8577, Miyagi, Japan
[email protected]
Brian Benicewicz
Rensselaer Polytechnic Institute
Department of Chemistry
Cogswell Lab
Troy, NY 12180, USA
[email protected]
Debasis Bera
University of Florida
202 Rhines Hall, Gale Lemerand
Drive
PO 116400
Gainesville, FL 32611, USA
[email protected]
Shlomo Berger
Technion
Materials Science and Engineering
Haifa, 32000, Israel
[email protected]
Iris Binyamin
IIBR
18A Bar-Kochva, Shmoorat Malibo
Ness Ziona, 74058, Israel
[email protected]
Lennart Bergström
Stockholm University
Inorganic Chemistry Dept
Arrhenius Laboratory
10691, Stockholm, Sweden
[email protected]
John Biteau
Essilor
8300 Sheen Drive
St. Petersburg, FL 33709, USA
[email protected]
Cory Berkland
The University of Kansas
2030 Becker Drive
Lawrence, KS 66047, USA
[email protected]
Jean-François Berret
Université Denis Diderot Paris-VII
UMR 7057 CNRS
10 rue Alice Domon et Léonie
Duquet
75205, Paris, France
[email protected]
Simon Biggs
University of Leeds
Institute of Particle Science and
Engineering
Houldsworth Building, Clarendon
Road
Leeds, West Yorkshire
LS22 7UD, United Kingdom
[email protected]
Bernard Paul Binks
University of Hull
Chemistry Dept
Hull, HU6 7RX, United Kingdom
[email protected]
Marcel Böhmer
Philips Research
High Tech Campus 11
5656 AE, Eindhoven, Netherlands
[email protected]
Stefan Bon
University of Warwick
Gibbett Hill Road
Coventry, CV4 7AL, United Kingdom
[email protected]
Kristien Bonroy
IMEC
Kapeldreef 75
3001, Heverlee, Belgium
[email protected]
Tony Boova
Beckman Coulter Inc
Miami, FL 33196, USA
[email protected]
Elodie Bourgeat-Lami
Polymer Colloids and Composites
LCPP-UMR 5265 CNRS/CPE/UCBL
43, Bd du 11 Novembre 1918, Bât.
308F
69616, Villeurbanne, France
[email protected]
313
Virginia Bouzas
Material Physics
University Complutense at Madrid
Avd Complutense s/n
28024, Madrid, Spain
[email protected]
Lyudmila Bronstein
Indiana University
Chemistry Dept
800 East Kirkwood Avenue
Bloomington, IN 47405, USA
[email protected]
Keith Bowman
Merck & Co, Inc
PO Box 4, WP14-2
West Point, PA 19486, USA
[email protected]
Richard Brotzman
Nanophase Technologies
Corporation
1318 Marquette Drive
Romeoville, IL 60446, USA
[email protected]
Ben Boyd
Monash University
Monash Institute of Pharmaceutical
Science
381 Royal Pde
Parkville, 3052, VIC, Australia
[email protected]
Hans-Gerd Boyen
Hasselt University
Institute for Materials Research
Wetenschapspark 1
3590 Diepenbeek, Belgium
[email protected]
Paul Braun
University of Illinois at UrbanaChampaign
1304 West Green Street
Urbana, IL 61801, USA
[email protected]
Roberta Brayner
Université Paris Diderot, ITODYS
case 7090, 2 place jussieu
75251, Paris 05, France
[email protected]
314
Michael Brown
CPS Instruments, Inc
311 Society Place
Newtown, PA 18940, USA
[email protected]
Ali Bumajdad
Kuwait University
Chemistry Dept
PO Box 5969
Safat 13060, Kuwait
[email protected]
Malee Bunjob
Ministry of Public Health
Dept of Medical Science
88/7 Tiwanon Road, Taradkwan
11000, Nonthaburi, Thailand
Peter Burkhard
University of Connecticut
Institute of Materials Science
97 North Eagleville Road
Storrs, CT 06269, USA
[email protected]
Daniel Burnett
2125 28th Street SW, Suite 1
Allentown, PA 18103, USA
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Matt Butler
LUM Corporation
16201 Dodd Street
Volente, TX 78641
[email protected]
Marissa Caldwell
Stanford University
20230 Forest Avenue
Cupertino, CA 95014, USA
[email protected]
Joe Campbell
Spectra Services, Inc
6359 Dean Parkway
Ontario, NY 14519, USA
[email protected]
David Cannon
900 South Taft Avenue
Loveland, CO 80537, USA
[email protected]
Everett Carpenter
Virginia Commonwealth University
Chemistry Dept
1001 West Main Street
PO Box 842006
Richmond, VA 23284, USA
[email protected]
Bob Carr
NanoSight Limited
2 Centre One, Lysander Way
Old Sarum Park
Salisbury, SP4 6BU, Wiltshire,
United Kingdom
[email protected]
Maria Teresa Celis
University of The Andes
La Hechicera – College of
Engineering
Mérida, 5101, Venezuela
[email protected]
Aravind Chakrapani
Novartis Vaccines and Diagnostics
4560 Horton Street, MS 4.3
Emeryville, CA 94608, USA
[email protected]
Julie Champion
California Institute of Technology
Department of Chemical Engineering
1200 E California Blvd
Pasadena, CA 91125, USA
[email protected]
Jean-Paul Chapel
CNRS/Rhodia Joint Laboratory
350 Georges Patterson Blvd
Bristol, PA 19007, USA
[email protected]
Thuy Truong Chastek
National Institute of Standards and
Technology
Polymers Division
100 Bureau Drive
Gaithersburg, MD 20899, USA
[email protected]
Byron Cheatham
CytoViva, Inc
300 North Dean Road
Suite 5 – PMB 157
Auburn, AL 36830, USA
[email protected]
Pei Lin Chen
Academia Sinica
Research Center for Applied
Sciences
128, Sect. 2 Academia Road,
Nankang
Taipei, 115, Taiwan
[email protected]
315
Youcun Chen
Anqing Normal University
School of Chemistry and Chemical
Engineering
128 South Linghu Road
Anqing, 246100, Anhui, PR China
[email protected]
Yit-Tsong Chen
Chemistry Dept
National Taiwan University and
Institute of Atomic and Molecular
Sciences
Academia Sinica
Taipei 106, Taiwan
[email protected]
Irina Chernyshova
Columbia University
500 West 120th Street
Mudd Bldg, Rm 918
New York, NY 10027, USA
[email protected]
Chun-Yi Chiu
Industrial Technology Research
Institute
Rm 806, Bldg 44, 195, Sec 4
Chung Hsing Road
Chutung, Hsinchu, 310, Taiwan ROC
[email protected]
Hee Jung Choi
Sejong University
98 Gunja-dong, Gwangjin-gu
Choongmoo-gwan, Rm 807
Seoul, 143747, South Korea
[email protected]
Sung-Min Choi
KAIST
Department of Nuclear and Quantum
Engineering
373-1 Gusong-dong, Yusong-gu
Daejon 305-701, Republic of Korea
[email protected]
316
Gan Moog Chow
National University of Singapore
Kent Ridge, 119260, Republic of
Singapore
[email protected]
Wallace C. H. Choy
University of Hong Kong
Department of Electrical and
Electronic Engineering
Pokfulam Road
Hong Kong, China
[email protected]
Anindarupa Chunder
12424 Research Park Way, Suite
400
[email protected]
Francesco Cignoli
CNR-IENI sect Milan
via R. Cozzi 53
20125, Milan, Italy
[email protected]
Leonardo Cinque
Colorado School of Mines
Department of Chemistry and
Geochemistry
1500 Illinois Street
Golden, CO 80401, USA
[email protected]
Guylhaine Clavel
University of Aveiro
Department of Chemistry and
CICECO
3810-193, Aveiro, Portugal
[email protected]
Daniel Clemans
Biology Dept
316 Mark Jefferson Bldg
[email protected]
David Cliffel
Vanderbilt University
Chemistry Dept
VU Station B 351822
Nashville, TN 37235-1822, USA
[email protected]
Karl Coleman
Durham University
Chemistry Dept
South Road
Durham, DH1 3LE, United Kingdom
[email protected]
Helmut Cölfen
Max Planck Institute of Colloids and
Interfaces
Research Campus Golm
Am Mühlenberg 1
14424 Potsdam, Germany
[email protected]
Vicki Colvin
Rice University
Chemistry Dept/Center for
Nanoscale Science & Technology
6100 Main Street, MS-60
Houston, TX 77005, USA
[email protected]
Giuseppe Compagnini
University of Catania
Chemistry Dept
Viale A. Doria 6
95125, Catania, Italy
[email protected]
Ronald Cook
TDA Research, Inc
4663 Table Mountain Drive
[email protected]
Thibaud Coradin
Chimie de la Matière Condensée de
Paris
Université Pierre et Marie CurieParis 6
4 place Jussieu
[email protected]
Sherman Cox
Specialty Minerals Inc
9 Highland Avenue
Bethlehem, PA 18017, USA
[email protected]
m
Piotr Cywinski
Friedrich-Schiller University Jena
Institute of Physical Chemistry
Lessingstrasse 10
D-07743, Jena, Germany
[email protected]
Qiu Dai
[email protected]
Dan Daly
University of Alabama
AIME
720 2nd Street
Tuscaloosa, AL 35487, USA
[email protected]
317
Eric Daniels
Lehigh University
Emulsion Polymers Institute
111 Research Drive
[email protected]
Jessie Desbiens
Université Laval
Département de chimie
2520 rue De Brugnon app3
Québec, G1M 2K7, Canada
[email protected]
Christian Daugaard
Haldor Topsøe A/S
Nymøllevej 55
DK-2800, Lyngby, Denmark
[email protected]
David Diaz
National Autonomous University of
Mexico
Faculty of Chemistry
3000 University Avenue
Coyoacan, Mexico City, 04510,
Mexico
[email protected]
C.G. (Kees) de Kruif
Utrecht University
Padualaan 8
3584 CH, Utrecht, Netherlands
[email protected]
Carol DeCann
Ortho Clinical Diagnostics
130 Indigo Creek Drive
Rochester, NY 14626, USA
[email protected]
Dale DeCann
Eastman Kodak Company
40 Brandon Circle
[email protected]
Hervé Dietsch
Fribourg Center for Nanomaterials,
FriMat
Chemin du Musée, 3
1700 Fribourg, Switzerland
[email protected]
Trong-On Do
Laval University
Chemical Engineering
Québec, G1K 7P4, Canada
[email protected]
Ahmet Faik Demirors
Utrecht University
Princetonplein 1
3584CC, Utrecht, Netherlands
[email protected]
Marina Dobrovolskaia
SAIC-Frederick, Inc.
National Cancer Institute at
Frederick
PO Box B
Frederick, MD 21702, USA
[email protected]
Zhaoxiang Deng
University of Science and
Technology of China
Chemistry Dept
96 Jinzhai Road
Hefei, Anhui 230026, China
[email protected]
Yao-Da Dong
Monash University
Monash Institute of Pharmaceutical
Science
381 Royal Pde
Parkville, VIC 3052, Australia
[email protected]
318
Elena Dormidontova
Case Western Reserve University
Macromolecular Science and
Engineering
337 KHSmith
2100 Adelbert Road
Cleveland, OH 44106, USA
[email protected]
Joydeep Dutta
Asian Institute of Technology
School of Engineering and
Technology
PO Box 4
Klong Luang, Pathumthani, 12120,
Thailand
[email protected]
Ekaterina Dovgolevsky
Technion – Israel Institute of
Technology
Russell Berrie Nanotechnology
Institute
Haifa, 32000, Israel
[email protected]
Prabir Dutta
The Ohio State University
Chemistry Dept
100 West 18th Avenue
Columbus, OH 43210, USA
[email protected]
Hongwei Duan
Emory University
101 Woodruff Circle, WMB Suite
2007
Atlanta, GA 30322, USA
[email protected]
Takeo Ebina
National Institute of Advanced
Industrial Science & Technology
Research Center for Compact
Chemical Process
Nigatake 4-2-1, Miyaginoku
[email protected]
Steve Duke
Auburn University
212 Ross Hall
Auburn, AL 36849-5127, USA
[email protected]
Nadia Edwin
National Institute of Standards and
Technology
100 Bureau Drive
[email protected]
Andrei Dukhin
Dispersion Technology Inc
364 Adams Street
Bedford Hills, NY 10507, USA
[email protected]
Inga Ennen
Bielefeld University
Physics Dept
Thin Films and Physics of
Nanostructures
Universitätsstr. 25
33615, Bielefeld, Germany
[email protected]
Yvon Durant
University of New Hampshire
G101 Parsons Hall
23 College Road
Durham, NH 03824, USA
[email protected]
319
Edurne Erkizia
Labein-Tecnalia
Calle Geldo, Edificio 700
Parque Tecnológico de Bizkaia
48160 (BIZKAIA), Derio, Spain
[email protected]
Anitha Ethirajan
University of Ulm
Institute of Organic Chemistry III
Albert-Einstein-Allee 11
89081, Ulm, Germany
[email protected]
Dennis Faler
PPG Industries
PO Box 9
Allison Park, PA 15101, USA
[email protected]
Jiyu Fang
Advanced Materials Processing &
Analysis Center
Mechanical, Materials, and
Aerospace Engineering
[email protected]
Claus Feldmann
Universität Karlsruhe
Engesserstrasse 15
76131 Karlsruhe, Germany
[email protected]
Si-Shen Feng
Chemical and Biomolecular
Engineering
4 Engineering Drive 4, Blk 05-02-06
Singapore, 117576, Singapore
[email protected]
320
Jennifer Fiegel
University of Iowa
Chemical and Biochemical
Engineering
115 South Grand Avenue, S215
PHAR
Iowa City, IA 52242, USA
[email protected]
Fernand Fiévet
Université Paris7-Denis Diderot,
ITODYS
UMR CNRS 7086, case 7090
2, place Jussieu
[email protected]
Zvi Finkelman
Gadot Laboratory Supplies Ltd
7, Habonim Street
PO Box 8757
42504, Netanya, Israel
[email protected]
Warren Ford
Oklahoma State University
Chemistry Dept
PS 107
Stillwater, OK 74078, USA
[email protected]
Stephen Foulger
Clemson University
School of Materials Science and
Engineering (COMSET)
91 Technology Drive, AMRL Bldg,
Rm 225
Anderson, SC 29625, USA
[email protected]
Hendrik Frank
University of Ulm
89081, Ulm, Germany
[email protected]
Rachel Frazier
University of Alabama
Alabama Institute of Manufacturing
Excellence
Box 870204
Tuscaloosa, AL 35487-0204, USA
[email protected]
Justyna Frelichowska
University of Lyon, LAGEP
43 bd du 11 Novembre 1918, bat.
308G
69622, Villeurbanne, France
[email protected]
Kouki Fujioka
International Medical Center of
Japan
Research Institute
1-21-1 Toyama, Shinjuku-ku
Tokyo, 162-8655, Japan
[email protected]
Timothy Fulghum
Baxter Healthcare
25212 West Illinois Route 120, WG32S
Round Lake, IL 60073, USA
[email protected]
Seiichi Furumi
National Institute for Materials
Science
1-2-1 Sengen
Tsukuba, 305-0047, Japan
[email protected]
Steven Gabris
Knolls Atomic Power Lab, Inc.
PO Box 7450, Bin 168
Schenectady, NY 12302, USA
[email protected]
François Ganachaud
Institut Charles Gerhardt-IAM,
UMR5253, ENSCM
34296, Montpellier, France
[email protected]
Xiaohu Gao
University of Washington
William H. Foege Bldg, N530M
Campus Box 355061
Seattle, WA 98195, USA
[email protected]
Miguel Angel Garcia
University Complutense at Madrid
Material Physics
Avd Complutense s/n
[email protected]
Miriam Gathen
Technical University of Dortmund
Institute of Materials Engineering
Leonhard-Euler-Str 2
44227, Dortmund, Germany
[email protected]
Fabienne Gauffre
Paul Sabatier University-CNRS
118 rte de Narbonne
31000, Toulouse, France
[email protected]
Corine Gerardin
Institut C. Gerhardt
CNRS ENSCM UMR 5618
34296, Montpellier, France
[email protected]
Andre Gesquiere
NanoScience Technology Center
[email protected]
321
Paul Geutjes
Radboud University
Nijmegen Medical Centre
Geert Grooteplein 26/28
6525 GA, Nijmegan, Netherlands
[email protected]
Emmanuel Giannelis
Cornell University
214 Bard Hall
Ithaca, NY 14850, USA
[email protected]
Michael Giersig
caesar research center
Nanoparticle Technology Dept
Ludwig-Erhard-Allee 2
D-53175, Bonn, Germany
[email protected]
Sophie Giraud
Commissariat à l’énergie atomique
(CEA)
DEN-DANS/DMN/SRMA/LTMEx
Centre de Saclay, bât 460
91191, Gif sur Yvette, France
[email protected]
Douglas Gish
University of Alberta
Electrical and Computer Engineering
W1-040, ECERF, 2nd floor
Edmonton, T6G 2V4, Alberta,
Canada
[email protected]
Christophe Goepfert
CILAS, SA
CEA Programs and Development
8, avenue Buffon – BP 6319, ZI La
Source
45100, Orleans, France
[email protected]
322
Eckhard Goernitz
Fraunhofer Institute for Applied
Polymer Research
Geiselbergstr 69
D14476, Potsdam-Golm, Germany
[email protected]
Yuval Golan
Ben Gurion University
Materials Engineering
Marcus Campus, Bldg 59
Beer-Sheva, 84105, Israel
[email protected]
Mark Gostock
Farfield Scientific Inc.
4514 Plummer Street
Pittsburgh, PA 15201, USA
[email protected]
Laurie Gower
Materials Science & Engineering
210A Rhines Hall
Gainesville, FL 32611-6400, USA
[email protected]
Richard Greenwood
University of Birmingham
Edgbaston
Birmingham, B15 2TT, United
Kingdom
[email protected]
Philippe Guarilloff
Chanel P-B
876 Centennial Avenue
Piscataway, NJ 08855, USA
[email protected]
Yuri Gun’ko
Trinity College Dublin
School of Chemistry
Dublin 2, Ireland
[email protected]
Ram Gupta
Auburn University
212 Ross Hall
[email protected]
Silvia Guterres
Universidade Federal do Rio Grande
do Sul
Av. Ipiranga, 2752
Porto Alegre, RS, 90610-000, Brazil
[email protected]
Heinrich Haas
Medigene AG
Lochhamer Str 11
82152, Martinsried, Germany
[email protected]
Judith Hadley
1400 Fountaingrove Parkway, M1
SE
Santa Rosa, CA 95403, USA
[email protected]
Elin Hammarberg
Universität Karlsruhe
Institute of Inorganic Chemistry
Engesserstr 15
76131, Karlsruhe, Germany
[email protected]
Takuya Harada
Technology
77 Massachusetts Avenue, 66-325
Cambridge, MA 02139, USA
[email protected]
Port Richey, FL 34668
[email protected]
Yasuhiko Hayashi
Nagoya Institute of Technology
Gokiso-cho, Showa-ku
Nagoya, 466-8555, Aichi, Japan
[email protected]
Regine Hedderich
Forschungszentrum Karlsruhe
Institute for Nanotechnology
POX 3640
[email protected]
Kevin Heitfeld
Southwest Research Institute
6220 Culebra Road
San Antonio, TX 78228, USA
[email protected]
Nathalie Herlin-Boime
Laboratoire Francis Perrin (CEACNRS URA 2453)
Service des Photons, Atomes et
Molécules
CEA Saclay, bat 522
91191, Gif/Yvette Cedex, France
[email protected]
Rupert Herrmann
Roche Diagnostics GmbH
Nonnenwald 2
82377, Penzberg, Germany
[email protected]
Tobias Hertel
Physics and Astronomy
6301 Stevenson Center Lane
Nashville, TN 37235, USA
[email protected]
Kerry Hasapidis
Particle Sizing Systems
8203 Kristel Circle
323
Margaret Hines
Evident Technologies, Inc
216 River Street, Suite 200
Troy, NY 12180, USA
[email protected]
Tomoaki Hino
Kinjo Gakuin University
College of Pharmacy
2-1723 Ohmori, Moriyama
Nagoya, Aichi, 463-8521, Japan
[email protected]
Rex Hjelm
MS H805
[email protected]
Robert Hoerr
Nanocopoeia, Inc
University of Minnesota
1246 West University Avenue, Suite
463
St. Paul, MN 55104, USA
[email protected]
Edward Hoff
Beckman Coulter Inc
Heinrich Hofmann
Ecole Polytechnique Fédérale de
Lausanne
Powder Technology Laboratory,
Station 12
1015, Lausanne, Switzerland
[email protected]
Benjamin Holt
University of Hull
Chemistry Dept
Kingston upon Hull, HU6 7RX,
United Kingdom
[email protected]
324
Liang Hong
Institute of Materials Research &
Engineering
3 Research Link
117602, Singapore
[email protected]
Sung Chul Hong
Sejong University
Nano Science & Technology
Rm 814, Choongmoo-gwan
98 Gunja-dong, Gwangjin-gu
Seoul, 143-747, South Korea
[email protected]
Tommy Horozov
University of Hull
Chemistry Dept
Cottingham Road
Hull, HU6 7RX, United Kingdom
[email protected]
Lien-chung Hsu
National Cheng-kung University
1 Ta-Hsueh Road
Tainan, 701, Taiwan
[email protected]
Michael Hu
Oak Ridge National Laboratory
Bldg 4500N, A034, MS 6181
Oak Ridge, TN 37831-6181, USA
[email protected]
Zheng Hu
Nanjing University
School of Chemistry & Chemical
Engineering
Hankou Road
Nanjing, 210093, Jiangsu, China
[email protected]
Dale Huber
Sandia National Laboratories
PO Box 5800, MS 1304
Albuquerque, NM 87185-1304, USA
[email protected]
Sergei Ivanov
Los Alamos National Lab
PO Box 5800, MS1304
1515 Eubank Avenue SE
Albuquerque, NM 87185, USA
[email protected]
Qun Huo
[email protected]
Isaac Iverson
INVISTA
PO Box 7000
Camden, SC 29020, USA
[email protected]
Stefan Hupfeld
University of Tromsø
Department of Pharmacy
Breivika
N-9037, Tromsø, Norway
[email protected]
Amane Jada
Université de Haute Alsace, ICSICNRS
15 rue Jean Starcky
68057, Mulhouse, France
[email protected]
Kendall Hurst
Auburn University
212 Ross Hall
[email protected]
Andreas Jahn
National Institute of Standards &
Technology
100 Bureau Drive, MS 8120
[email protected]
Kuo Chu Hwang
National Tsing Hua University
Chemistry Dept
Hsinchu, 30013, Taiwan
[email protected]
Stefan Jaksch
University of Innsbruck
Technikerstrasse 25
6020, Innsbruck, Austria
[email protected]
Taeghwan Hyeon
Seoul National University
School of Chemical & Biological
Engineering
599 Gwanangno, Gwanak-gu
[email protected]
Du-Jeon Jang
Seoul National University
School of Chemistry
NS60, Sinlim-Dong
[email protected]
John Inderdohnen
Brookhaven Instruments Corporation
750 Blue Point Road
Holtsville, NY 11742, USA
Valérie Jeanne-Rose
L’Oreal
1 Avenue Eugene Schueller, BP 22
93601, Aulnay Sous Bois, France
[email protected]
325
Yeon Tae Jeong
Pukyong National University
San 100, Nam-gu
Yongdang Dong
Busan, 608-739, South Korea
[email protected]
Li Jia
The University of Akron
Polymer Science Dept
Goodyear Polymer Center
Akron, OH 44325-3909, USA
[email protected]
Peng Jiang
[email protected]
Isaac Ojea Jiménez
Institut Català de Nanotecnologia
Campus UAB, building Q, 3rd floor
08193, Bellaterra, Barcelona, Spain
[email protected]
Song Jin
University of Wisconsin-Madison
Chemistry Dept
1101 University Avenue, Room 3363
Madison, WI 53706-1396, USA
[email protected]
Steven Johnson
Penn State University-DuBois
110J DEF Bldg, College Place
DuBois, PA 15801, USA
[email protected]
Paul Jones
Imerys Minerals Limited
Par Moor Centre
Par Moor Road
Kingdom
[email protected]
326
David Jovanovic
Particle Technology Labs, Ltd
555 Rogers Street
Downers Grove, IL 60515, USA
[email protected]
Lucienne Juillerat-Jeanneret
University of Lausanne
Bugnon 25
CH1011, Lausanne, VD, Switzerland
[email protected]
Dylan Jung
The University of Auckland
Centre for Advanced Composite
Materials
Private Bag 92019
Auckland, 0152, New Zealand
[email protected]
Charalambos Kaittanis
NanoScience Technology Center,
Suite 400
12424 Research Parkway
[email protected]
Gregory Kalyuzhny
San Diego State University
Department of Chemistry
5500 Campanile Drive
San Diego, CA 92182-1030, USA
[email protected]
Hidehiro Kamiya
Tokyo University of Agriculture &
Technology
2-24-16, Naka-cho
Koganei, 184-8588, Tokyo, Japan
[email protected]
Yao Kanga
Imerys Minerals Limited
Par Moor Centre
Par Moor Road
Kingdom
[email protected]
Soumitra Kar
[email protected]
Alamgir Karim
Technology
Polymers Division, MS8541
[email protected]
Mohammad Rezaul Karim
Kyungpook National University
1370 Sankyeokdong, Bukgu
Daegu, 702-701, South Korea
[email protected]
Andrey Karpov
BASF
Carl-Bosch-Strasse 38
GCC/PS – M 301
D-67056, Ludwigshafen, Germany
[email protected]
Esko Kauppinen
Helsinki University of Technology
Laboratory of Physics/Center for
New Materials
Puumiehenkuja 2
FI-02150 Espoo, Finland
[email protected]
Polymer, Textile and Fiber
Engineering
801 Ferst Drive NW, MRDC 1
Atlanta, GA 30332-0295, USA
[email protected]
Haruma Kawaguchi
Keio University
School of Science and Technology
3-14-1 Hiyoshi
Yokohama, 223-8522, Japan
[email protected]
Masanori Kawase
Mitsubishi Tanabe Pharma
Corporation
3-16-69 Kashima, Yodogawa-ku
Osaka, 532-8505, Japan
[email protected]
Tadashi Kawazoe
University of Tokyo
Electronics Engineering
Bldg 9, Rm 213
2-11-16 Yayoi Bunkyo-ku
[email protected]
Herbert Kellner
European Patent Office
Erhardtstr 27
80469, Munich, Germany
[email protected]
Neil Kemp
Institut de Physique et de Chimie
des Matériaux de Strasbourg
23 rue du Loess, BP43
67034, Strasbourg, France
[email protected]
Jasmeet Kaur
Georgia Institute of Technology
327
Saiful Khondaker
and
Department of Physics
12424 Research Pkwy, Suite 400
[email protected]
Mikhail Khoudiakov
SDC Technologies
45 Perker, Suite 100
Irvine, CA 92616, USA
[email protected]
Hongkyu Kim
Corning Inc
SP-PR-01-3
Chatham Township, 14831, USA
[email protected]
Jung Hyun Kim
Yonsei University
134 Shinchon-dong, Seodaemun-ku
[email protected]
Min Sung Kim
San-100, Nam-gu, Yongdang Dong,
[email protected]
Young Seok Kim
Korea Electronics Technology
Institute
#68 Yatap-dong, Bundang-gu
Seongnam-si, 463-816, Gyeonggido, South Korea
[email protected]
Hideki Kitano
Bridgestone Americas
1200 Firestone Parkway
Akron, OH 44317, USA
328
[email protected]
Sungho Ko
Korea Food Research Institute
516 Baekhyun-Dong, Bundang-Ku
Sungnam, 463-746, Gyeonggi,
South Korea
[email protected]
Seong Jin Koh
University of Texas at Arlington
500 West 1st Street, Woolf Hall, Rm
325
Arlington, TX 76019, USA
[email protected]
Horng-Show (Frank) Koo
Ming-Hsin University of Science &
Technology
Optoelectronic System Engineering
No. 1, Hsin-Hsin Road, Hsinfeng
[email protected]
Christian Koos
Carl Zeiss AG
73446, Oberkochen, Germany
[email protected]
William Kopesky
Particle Technology Labs, Ltd
555 Rogers Street
Downers Grove, IL 60515, USA
[email protected]
Brian Korgel
University of Texas at Austin
One University Station, CO 400
Austin, TX 78712, USA
[email protected]
Tanya Kosc
University of Rochester
Laboratory for Laser Energetics
250 East River Road
[email protected]
Nicholas Kotov
University of Michigan
2300 Hayward
Ann Arbor, MI 48109, USA
[email protected]
Nina Kovtyukhova
The Pennsylvania State University
Department of Chemistry, 104
Chemistry Bldg
[email protected]
James Krajewski
DuPont Research and Engineering
Technology
Experimental Station
Wilmington, DE 19880, USA
[email protected]
Todd Krauss
Chemistry Dept
120 Trustee Road
[email protected]
Gabriele Kremser
Graz University of Technology
Institute for Chemistry & Technology
of Organic Materials
Stremayrgasse 16
8010, Graz, Austria
[email protected]
2013, Skjetten, Norway
[email protected]
Jitendra Kumar
Indian Institute ofTechnology Kanpur
Materials Science Programme
206 ACMS Bldg
Kanpur, 208016, UP, India
[email protected]
Nanjundan Ashok Kumar
San-100, Nam-gu, Yongdang Dong
[email protected]
Sonia Kumar
T2 Biosystems
286 Cardinal Medeiros
[email protected]
Masashi Kunitake
Kumamoto University
New Frontier Science
39-1 Kurokami 2-chome
Kumamoto, 860-8555, Japan
[email protected]
Chiung Wen Kuo
Academia Sinica
Research Center for Applied
Sciences
128, Sect 2, Academia Road,
Nankang
Taipei, 115, Taiwan
[email protected]
Angelos Kyrlidis
Cabot Corporation
157 Concord Road
Billerica, MA 01821, USA
[email protected]
Helge Kristiansen
Conpart
Lahaugmovelen 1, Bygg 36
329
Raphael Labruere
University of South Florida
4202 East Fowler Avenue, CHE
205A
8931 Iron Oak Avenue
Tampa, FL 33620-5250, USA
[email protected]
Silvia Lacerda
Technology
Polymers Division
100 Bureau Drive
[email protected]
Anna Lähde
Laboratory of Physics & Center for
New Materials
PO Box 5100
02150 Espoo, Finland
[email protected]
Richard M. Laine
University of Michigan
2300 Hayward Street
Ann Arbor, MI 48109-2136, USA
[email protected]
Mathias Lakatos
Technische Universität Dresden
Institute for Materials Science
Hallwachstrasse 3
D-01062, Dresden, Germany
[email protected]
Andreas Lammel
Technische Universität München
International Graduate School of
Science & Engineering
Arcistrasse 21
[email protected]
330
Katharina Landfester
University of Ulm
89081, Ulm, Germany
[email protected]
Kenneth Lau
Drexel University
Chemical & Biological Engineering
3141 Chestnut Street, CAT Rm 278
Philadelphia, PA 19104, USA
[email protected]
Roger Leblanc
University of Miami
Chemistry Dept
Cox Science Center
1301 Memorial Drive
Coral Gables, FL 33146
[email protected]
Hae Ri Lee
Kumho Petrochemical
57-1, Hwaam-Dong, Yuseong-Gu
Daejeon, 305-348, South Korea
[email protected]
Hyun Woo Lee
Kyungpook National University
Advanced Organic Materials Science
& Engineering
1370 Sankyeokdong, Bukgu
Deagu, 702-702, South Korea
[email protected]
Jung Min Lee
Yonsei University
134 Shinchon-dong, Seodaemun-gu
[email protected]
Sun Jong Lee
Yonsei University
134 Shinchon-dong, Seodaemun-gu
[email protected]
Lars Leidolph
IBU-tec advanced materials GmbH
Hainweg 9-10
D-99425, Weimer, Germany
[email protected]
Ingo Leubner
Crystallization Consulting
35 Hillcrest Drive
Penfield, NY 14526-2411, USA
[email protected]
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Tong Leung
University of Waterloo
Chemistry Dept
200 University Avenue West
Waterloo, N2L 3G1, Ontario, Canada
[email protected]
Chen-Zhong Li
Florida International University
Biomedical Engineering
10555 West Flager Street
[email protected]
Yu Li
Rensselaer Polytechnic Institute
Chemistry & Chemical Biology
110 8th Street, 120 Cogswell
Troy, NY 12180, USA
[email protected]
Ben Lich
FEI Company – Electron Optics BV
Achtsteweg Noord 5
5651 GG, Eindhoven, Netherlands
[email protected]
Yong Taik Lim
Korea Research Institute of
Bioscience & Biotechnology
BioNanotechnology Research
Center
52 Eoeun-dong, Yuseong-gu
[email protected]
Albert Lindner
Erhardtstr 27
[email protected]
Victor S.Y. Lin
Iowa State University
Chemistry Dept
0755 Gilman Hall
Ames, IA 50011, USA
[email protected]
Chao Liu
Nanosys Inc
2625 Hanover Street
Palo Alto, CA 94304, USA
[email protected]
Xiong (Shawn) Liu
[email protected]
Yonglin Liu
Technology
Optical Technology Division
100 Bureau Drive, MS 8443
Gaithersburg, MD 20899-8443, USA
[email protected]
331
Yue Liu
Ferro Corp
1789 Transelco Drive
Penn Yan, NY 14527, USA
[email protected]
Luis Liz-Marzán
University of Vigo
Physical Chemistry
Campus Universitario
E-36310, Vigo, Spain
[email protected]
Cefe López
Instituto de Ciencia de Materiales de
Madrid (CSIC)
Calle Sor Juana Inés de la Cruz 3
[email protected]
Cédric Louis
Nano-H SAS
25 rue royale
69001, Lyon, France
[email protected]
Tao Lowe
Surgery, Bioengineering, Materials
Science & Engineering
500 University Drive
Hershey, PA 17033, USA
[email protected]
Wensheng Lu
Chinese Academy of Sciences
Institute of Chemistry
No. 2, Bei Yi Jie, Zhong Guan Cun
Beijing, 100080, China
[email protected]
Yunfeng Lu
UCLA
Los Angeles, CA 90095, USA
[email protected]
332
Chuck Ludwig
CytoViva, Inc
300 North Dean Road
Suite 5, PMB157
Yingwu Luo
Zhejiang University
State Key Lab of Chemical
Engineering
38 ZheDa Road
Hangzhou, 310027, China
[email protected]
Raymond Mackay
Clarkson University
5151 North A1A, Unit 110
Vero Beach, FL 32963, USA
[email protected]
Noriyoshi Manabe
International Medical Center of
Japan
1-21-1 Toyama, Shinjuku-ku
[email protected]
Ramalinga Mangalaraja
University of Concepción
Materials Engineering
Edmundo Larenas 270
Concepción, 407-0409, Chile
[email protected]
J. Adin Mann, Jr.
Case Western Reserve University
Case School of Engineering
10900 Euclid Avenue, A.W. Smith
Rm 129
Cleveland, OH 44106-7217, USA
[email protected]
Liberato Manna
National Nanotechnology Lab/CNRINFM
Distretto Tecnologico – Isufi
Via Arnesano Km 5
73100, Lecce, Italy
[email protected]
Gil Markovich
Tel Aviv University
School of Chemistry
Tel Aviv, 69978, Israel
[email protected]
Michael Markowitz
Naval Research Laboratory
Bio/Molecular Science & Engineering
4555 Overlook Avenue SW, Code
6900
Washington, DC 20375, USA
[email protected]
Melanie Martin
265 Clover Street
Rochester, NY 14610-2246, USA
[email protected]
Luigi Martiradonna
National Nanotechnology Lab/CNRINFM
Distretto Tecnologico
Via Arnesano
73100, Lecce, Italy
[email protected]
Alessandro Martucci
Università de Padova
Ingegneria Meccanica Settore
Materiali
Via Marzolo, 9
35131, Padova, Italy
[email protected]
46 Grafton Street
Manchester, M13 9NT, United
Kingdom
[email protected]
Yoshitake Masuda
2266-98 Anagahora, Shimoshidami
Moriyama-ku
Nagoya, 463-8560, Japan
[email protected]
Masaru Matsuo
Nara Women’s University
Kitauoya-Nishi-Machi
Nara City, 630-8263, Japan
[email protected]
Hedi Mattoussi
US Naval Research Lab
Optical Sciences Div, Code 5611
4555 Overlook Avenue SW
[email protected]
Rachel McConnell
DuPont Air Products NanoMaterials,
LLC
2441 West Erie Drive
Tempe, AZ 85282, USA
[email protected]
Matthew McMahon
Technology
Center for Nanoscale Science &
Technology
100 Bureau Drive, MS 6201, Bldg
216/A157
[email protected]
Ombretta Masala
Nanoco Technologies Ltd
333
Wolfgang Meier
University of Basel
Chemistry Dept
Klingelbergstr 80
4056, Basel, Switzerland
[email protected]
Victor Manuel Menéndez-Flores
Leibniz University of Hannover
Institute for Technical Chemistry
Callinstr 3
D-30167, Hannover, Germany
[email protected]
Ana Menéndez-Manjón
Laser Zentrum Hannover e.V.
Hollerithallee 8
30419, Hannover, Germany
[email protected]
Mary Meza
Bangs Laboratories, Inc
9025 Technology Drive
Fishers, IN 46038, USA
[email protected]
Nadine Millot
Université de Bourgogne/CNRS
9 avenue Alain Savary, BP 47 870
21078, Dijon, France
[email protected]
G. Jimmy Mills
Auburn University
Chemistry & Biochemistry Dept
179 Chemistry Bldg
[email protected]
David Mines
Inotech Biosystems International
15713 Crabbs Branch Way
Derwood, MD 20855, USA
[email protected]
Sanjay Mishra
334
The University of Memphis
Physics Dept
Manning 226
Memphis, TN 38152, USA
[email protected]
Ana Morfesis
Malvern Instruments
117 Flanders Road
Westborough, MA 01581, USA
[email protected]
Tom Morgan
249 Materials Research Labs
Hastings Road
[email protected]
Ian Morrison
Cabot Corporation
157 Concord Road
Billerica, MA 01821, USA
[email protected]
Hanna Mouaziz
Université Claude Bernard Lyon 1 –
LAGEP
bât 308G ESCPE-Lyon, 2 ème
étage, bureau G206
43 bd du 11 Novembre 1918
69622, Villeurbanne Cedex, France
[email protected]
Miran Mozetic
Jozef Stefan Institute
Plasma Laboratory
39 Jarnova cesta
1000, Ljubljana, Slovenia
[email protected]
Arup Mukherjee
Calcutta University
Chemical Technology Dept
92, APC Road
Kolkata, 700009, India
[email protected]
Gautam Mukhopadhyay
Indian Institute of TechnologyBombay
Physics Dept
Powai, Mumbai, 400076, India
[email protected]
Pragati Mukhopadhyay
Indian Institute of TechnologyBombay
Centre fo Research in
NanoTechnology & Science
Powai, Mumbai, 400076, India
[email protected]
Jawad Naciri
Naval Research Laboratory
Center for Bio/Molecular Science &
Engineering
4555 Overlook Avenue SW, Code
6930
[email protected]
Kei Nakai
University of Tsukuba
Institute of Clinical MedicineNeurosurgery
1-1-1 Tennodai
Tsukuba City, 305-8575, Japan
[email protected]
Moshe Narkis
Technion-IIT
Haifa 32000, Israel
[email protected]
Technion-IIT
Environmental Engineering
Haifa 32000, Israel
[email protected]
Sudip Nath
[email protected]
Paola Nativo
The University of Liverpool
Chemistry Dept
Crown Street
Liverpool, L69 7ZD, United Kingdom
[email protected]
Sharma Neeraj
3M Company
3M Center, 201-4N-01
St. Paul, MN 55144-1000, USA
[email protected]
Markus Niederberger
ETH Zurich
Wolfgang-Paull-Strasse 10
8093 Zurich, Switzerland
[email protected]
Michael Ngo
Abbott Vascular
3200 Lakeside Drive
Santa Clara, CA 95054, USA
[email protected]
Takasi Nisisako
Tokyo Institute of Technology
Precision and Intelligence Lab
R2-6, 4259 Nagatsuta-cho, Midori-ku
Yokohama, 226-8503, Japan
[email protected]
Nava Narkis
335
Nitin Nitin
Southwest Research Institute
Biomaterials & Nanoencapsulation
6620 Culbera Road
[email protected]
Ulf Nobbmann
Malvern Instruments Inc
117 Flanders Road
Westboro, MA 01581, USA
[email protected]
Alireza Nojeh
University of British Columbia
Electrical & Computer Engineering
2332 Main Mall, Kaiser 4041
Vancouver, V6T 1Z4, BC, Canada
[email protected]
Hani Nur
University of Greenwich at Medway
Medway Sciences
Central Avenue, Chatham Maritime
Chatham, ME4 4TB, Kent, United
Kingdom
[email protected]
Shinsuke Oba
Astellas Pharma Inc
180, Ozumi
Yaizu-shi, 425-0072, Shizuoka,
Japan
[email protected]
Joo Yub Oh
Kumho Petrochemical
57-1, Hwaam-Dong, Yuseong-Gu
[email protected]
Charlene Ong
DSO National Laboratories
20 Science Park Drive
118230, Singapore
[email protected]
336
M. Carmen Ortega-Plaza
Erhardtstrasse 27
[email protected]
Eiji Osawa
NanoCarbon Research Institute
AREC, Textile Science Engineering
Shinshu University
3-15-1, Tokida, Ueda
Nagano, 386-8567, Japan
[email protected]
Brian Osmondson
TSI Incorporated
500 Cardigan Road
Shoreview, MN 55126, USA
[email protected]
Ulrich Oswald
Erhardtstrasse 27
[email protected]
Giulio Paciotti
Cytimmune Sciences, Inc
9640 Medical Center Drive
Rockville, MD 20850, USA
[email protected]
Umaporn Paiphansiri
University of Ulm
Ulm, 89069, Germany
[email protected]
Balaji Panchapakesan
University of Delaware
140 Evans Hall
Newark, DE 19706, USA
[email protected]
Priyadarshi Panda
Technology
511-A Ashdown House
305 Memorial Drive
[email protected]
Anne-Laure Papa
Université de Bourgogne/CNRS
9 Avenue Alain Savary, BP 47 870
Dijon, 21078, France
[email protected]
Chantal Paquet
National Research Council of
Canada
Steacie Institute for Molecular
Science
100 Sussex Drive
Ottawa, K1A 0R6, Ontario, Canada
[email protected]
Wolfgang Parak
Philipps Universität Marburg
Fachbereich Physik
Renthof 7
35037, Marburg, Germany
[email protected]
Dong-June Park
Korea Food Research Institute
516 Baekhyun-dong, Bundang-ku
Sungnam, Gyeonggi-do, 463-746,
South Korea
[email protected]
Jung Jin Park
Technology
Polymers Division
100 Bureau Drive, Bldg 224, Rm
B232
[email protected]
Joung Kyu Park
Chemical Technology
Jang-dong 100, Yuseong
[email protected]
Chetak Patel
12424 Research Pavillion, Suite 400
[email protected]
Andreas Pein
Graz University of Technology
Institute for Chemistry & Technology
of Organic Materials
Stremayrgasse 16
8010, Graz, Austria
[email protected]
David Peisel
Malvern Instruments
117 Flanders Road
Westborough, MA 01581, USA
[email protected]
Robert Pelton
McMaster University
Chemical Engineering Dept,
JHE/136B
1260 Main Street West
Hamilton, L8S 4L7, Ontario, Canada
[email protected]
Clara Pereira
Universidade do Porto
Departamento de
Química/REQUIMTE
Rua do Campo Alegre
4169-007 Porto, Portugal
[email protected]
337
Alain Perez
Université Claude Bernard Lyon
1/CNRS
Laboratoire de Physique de la
Matière Condensée et
Nanostructures
Domaine Scientifique de la Doua
69622, Villeurbanne cedex, France
[email protected]
J. Manuel Perez
[email protected]
Danielle Petko
GE Global Research
One Research Circle
Niskayuna, NY 12309, USA
[email protected]
Nigel Pickett
Nanoco Technologies Ltd
46 Grafton Street
Manchester, M13 9NT, United
Kingdom
[email protected]
Jeffrey Pietryga
MS J567, PO Box 1663
[email protected]
Steffen Pilotek
Buhler Inc
701 Brazos #500
Austin, TX 78701, USA
[email protected]
Nicola Pinna
University of Aveiro
Chemistry Dept/CICECO
338
Campus Universitario de Santiago
3810-193, Aveiro, Portugal
[email protected]
Jean-Yves Piquemal
Université Paris 7, ITODYS
2 place Jussieu, Tour 44-45, case
7090
[email protected]
Michael Pishko
Texas A&M University
255A Jack E. Brown Engineering
Bldg
3122 TAMU
College Station, TX 77843-3122,
USA
[email protected]
Marc Plaisant
200 Rhines Hall, PO Box 116400
[email protected]
Johan Pluyter
International Flavors & Fragrances
(IFF)
1515 State Highway 36
Union Beach, NJ 07735, USA
[email protected]
Mark Poggi
Q-Sense Inc.
808 Landmark Drive, Suite 124
Glen Burnie, MD 21061, USA
[email protected]
Adriana Pohlmann
Universidade Federal do Rio Grande
Do Sul
Av. Bento Gonçalves, 9500
PO Box 15003
Porto Alegre, RS, 91501-970, Brazil
[email protected]
Marc Porter
University of Utah
USTAR Center for Nanobiosensors
383 Colorow Drive
Salt Lake City, UT 84108-1201,
USA
[email protected]
Clint Potter
NanoImaging Services, Inc.
10931 North Torrey Pines Road,
Suite 108
San Diego, CA 92037, USA
[email protected]
Jon Preece
University of Birmingham
School of Chemistry – Edgbaston
Birmingham, B15 2TT, United
Kingdom
[email protected]
Vanessa Prevot
Université Blaise Pascal
Laboratoire des Matériaux
Inorganiques-UMR 6002
24, Avenue des Landais
63177, Aubière cedex, France
[email protected]
Zhiming Qiu
Coating Research Institute
[email protected]
University of Ulm
D-89081, Ulm, Germany
[email protected]
Kamil Rahme
Université Paul Sabatier
Laboratoire des IMRCP
118, Rte de Narbonne
31062, Toulouse cedex 9, France
[email protected]
Janne Raula
Laboratory of Physics & Center for
New Materials
PO Box 5100, Puumiehenkuja 2
FI-02150, Espoo, Finland
[email protected]
Serge Ravaine
Université Bordeaux-1
Centre de Recherche Paul
Pascal/CNRS
115 avenue du Dr. A. Schweitzer
33600, Pessac, France
[email protected]
Keith Redford
Conpart as
Lahaugmoveien 1, Bygg 36
2013, Skjetten, Norway
[email protected]
Rocío Redón
Universidad Nacional Autónoma de
México
Lab de Materiales y Nanotecnologia,
CCADET
Cd Universitaria, AP 70-186
México City, CP 04510, México
[email protected]
Lakshminarayanan Ragupathy
339
Joseph Reiner
Technology
100 Bureau Drive
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Clemens Richert
University of Karlsruhe
Institute for Organic Chemistry
Fritz-Haber-Weg 6
[email protected]
Chris Roberts
Auburn University
212 Ross Hall
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Ong Shin Rong
DSO National Laboratories
20 Science Park Drive
118230, Singapore
[email protected]
Eva-Maria Rosenbauer
University of Ulm
[email protected]
Gil Rosenman
Tel Aviv University
School of Electrical Engineering
Ramat Aviv
Tel Aviv, 69978, Israel
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Sandra Rosenthal
Chemistry Dept
SC 7303, Box 1822, Station B
340
[email protected]
Kristine Rosfjord
University of Maryland
College Park, MD 20742, USA
[email protected]
Renate Rossmanith
University of Ulm
[email protected]
Vincent Rotello
University of Massachusetts
Chemistry Dept
710 North Pleasant Street
Amherst, MA 01003, USA
[email protected]
Parul Rungta
Clemson University
COMSET, AMRL Bldg
91 Technology Drive
Anderson, SC 29625, USA
[email protected]
Marcel Ruppert
University of Ulm
[email protected]
Fouad Salhi
National Starch & Chemical
10 Finderne Avenue
Bridgewater, NJ 08807, USA
[email protected]
Jarno Salonen
University of Turku
Physics Dept
Vesilinnantie 3
FI-20014, Turku, Finland
[email protected]
Swadeshmukul Santra
[email protected]
Sourangsu Sarkar
[email protected]
Pierre Sarrazin
École Française de Papeterie et des
Industries Graphiques
LGP2, 461 rue de la Papeterie BP65
38402, Saint Martin d’Hères cedex,
France
[email protected]
Toshifumi Satoh
Hokkaido University
N13W8, Kita-ku
Sapporo, 006-8628, Japan
[email protected]
Steven Saunders
Auburn University
212 Ross Hall
[email protected]
Tsutomu Sawada
Science
1-1, Namiki
Tsukuba, Ibaraki, 3050044, Japan
[email protected]
Rebecca Sawayda
DuPont AirProducts Nanomaterials
LLC
2441 West Erie Drive
Tempe, AZ 85282, USA
[email protected]
Susann Schachschal
Technische Universität Dresden
Makromolecular/Textile Chemistry
Mommsenstr 4
01062 Dresden, Germany
[email protected]
Frank Scheffold
University of Fribourg
Department of Physics
Chemin du Musée 3
1700 Fribourg, Switzerland
[email protected]
Thomas Scheibel
University of Bayreuth
Biomaterials Dept, FAN-D
Universitätsstr 30
95440 Bayreuth, Germany
[email protected]
Jay Schild
Microtrac
12501-A 62nd Street North
Largo, FL 33773, USA
[email protected]
Winston Schoenfeld
CREOL: College of Optics &
Photonics
4000 Central Florida Blvd, PO Box
162700
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Philip Schultz
Abbott Labs
Dept 09FJ, Bldg AP20
Abbott Park, IL 60064, USA
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V. Prasad Shastri
Biomedical Engineering
5824 Stevenson Center
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Iris Schumacher
Kimberly-Clark Corporation
302 Perimeter Center North, #2222
Atlanta, GA 30346, USA
[email protected]
David Shaw
Rockwood Additives Ltd
Moorfield Road
Widnes, WA8 3AA, United Kingdom
[email protected]
Mark Schwabel
3M Company
3M Center, Bldg 251-2B-11
Maplewood, MN 55144-1000, USA
[email protected]
Ginger Shi
Behr Process Corporation
3400 West Segerstrom Avenue
Santa Ana, CA 92704, USA
[email protected]
Carole Sentein
Commissariat à l’énergie atomique
(CEA)
DEN-DANS/DMN/SRMA/LTMEx
Centre de Saclay, bât 460
91191, Gif sur Yvette, France
[email protected]
Jau-Ye Shiu
Academia Sinica
128 Sect 2, Academia Road
Nankang
Taipei, 115, Taiwan
[email protected]
Liza Seymour
Erhardtstr 27
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Emek Seyrek
Institute Charles Sadron
CNRS-Campus Cronenbourg
23 rue du Loess, BP 84047
67034, Strasbourg, France
[email protected]
Tigran Shahbazyan
Jackson State University
Physics Dept
Jackson, MS 39217, USA
[email protected]
342
Meisha Shofner
Georgia Institute of Technology
Polymer, Textile, & Fiber
Engineering
801 Ferst Drive
Atlanta, GA 30332-0295, USA
[email protected]
Sanjeev Kumar Shrivastava
Indian Institute of Technology-Delhi
IDDC
Hauz Khas, 110016, New Delhi,
India
[email protected]
Lorette Sicard
Université Paris 7, ITODYS
UMR CNRS 7086
2 place Jussieu
[email protected]
Guillermo Smart
Beckman Coulter Inc
[email protected]
Renaud Sicard
University of South Florida
4202 East Fowler Avenue, CHE
205A
Tampa, FL 33620-5250, USA
[email protected]
Alex Smirnov
North Carolina State University
Chemistry Dept, Box 8204
2620 Yarbrough Drive
Raleigh, NC 27695-8204, USA
[email protected]
Wolfgang Sigmund
225A Rhines Hall
Gainesville, FL 32611-6400, USA
[email protected]
Igor Sokolov
Clarkson University
NanoBio-Laboratory
8 Clarkson Avenue
Potsdam, NY 13699-5820, USA
[email protected]
Leif Simonsen
Invista
Benger Lab
400 DuPont Blvd
Waynesboro, VA 22980, USA
[email protected]
Anongnat Somwangthanaroj
Chulalongkorn University
773 Rama 3 rd
Bangpongpang, Yannawa
Bangkok, 10120, Thailand
[email protected]
Amit Singhal
NEI Corporation
400 East Apgar Drive
Somerset, NJ 08873, USA
[email protected]
Qing Song
National Renewable Energy
Laboratory
1617 Cole Blvd, MS3216
[email protected]
Ganesh Skandan
NEI Corporation
400 Apgar Drive, Suite E
Somerset, NJ 08873, USA
[email protected]
Alfie Spencer
Reckitt Benckiser
One Philips Parkway
Montvale, NJ 07645, USA
[email protected]
Lisa Slater
Eastman Kodak Company
Kodak Research Labs
1669 Lake Avenue
[email protected]
343
Doris Spori
Laboratory for Surface Science &
Technology
ETH Zurich
Wolfgang-Pauli-Str 10
HCI E 463.2
8093, Zürich, Switzerland
[email protected]
Ming Su
Mechanical, Materials, & Aerospace
Engineering
[email protected]
Bill Staskiewicz
Malvern Instruments Inc
117 Flanders Road
Westboro, MA 01581, USA
[email protected]
Seigi Suh
DuPont
14 T.W. Alexander Drive
RTP, NC 27709, USA
[email protected]
Martin Steinhart
Max Planck Institute of
Microstructure Physics
Weinberg 2
06121 Halle, Germany
[email protected]
Kang Sun
Shanghai Jiao Tong University
800 Dongchuan Road
Shanghai, 200240, China
[email protected]
Francesco Stellacci
Technology
77 Massachusetts Avenue, Rm 134053
[email protected]
Mahendra Sunkara
University of Louisville
Ernst Hall, Rm 106
Louisville, KY 40292
[email protected]
Laura Steller
IFW Dresden
Magnetic & Acoustic Resonances
Dept
Surface Dynamic Group
Helmholtzstr 20
D-01069, Dresden, Germany
[email protected]
Johan Stiefelhagen
Utrecht University, Debye Institute
Ornstein Laboratorium
Princetonplein 1
3584 CC, Utrecht, Netherlands
[email protected]
344
Milan Sykora
Physical Chemistry & Applied
Spectroscopy
MS J567
[email protected]
Amra Tabakovic
221 Materials Research Lab
[email protected]
Atsushi Takahara
Kyushu University
Institute for Materials Chemistry &
Engineering
744 Motooka, Nishi-ku
Fukuoka, 819-0395, Japan
[email protected]
Yoshihiko Takeda
Science
Quantum Beam Center
3-13 Sakura
Tsukuba, 305-0003, Ibaraki, Japan
[email protected]
Sonia Taktak
T2 Biosystems
286 Cardinal Medeiros
[email protected]
Emanuela Tamburri
Università de Roma “Tor Vergata”
Scienze e Tecnologie
Chimiche/MINASlab
Via della Ricerca Scientifica
00133, Roma, Italy
[email protected]
Geok Bee Teh
Universiti Tunku Abdul Rahman
Bioscience & Chemistry Dept
Jalan Genting Kelang, Setapali
53300, Kuala Lumpur, Malaysia
[email protected]
Andre ten Elshof
University of Twente
MESA+ Institute for Nanotechnology
PO Box 217
7500 AE, Enschede, Netherlands
[email protected]
Mauricio Terrones
IPICYT
Camino a la Presa San Jose 2055
Col. Lomas 4a. seccion
San Luis Potosi, SLP, 78216, Mexico
[email protected]
Hiroyuki Tetsuka
Nigatake 4-2-1, Miyagino-ku
[email protected]
John Texter
Eastman Michigan University
School of Engineering & Technology
[email protected]
Curt Thies
Thies Technology
921 American Pacific Drive, Suite
309
Henderson, NV 89014, USA
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Martin Thomas
Quantachrome Instruments
1900 Corporate Drive
Boynton Beach, FL 33426, USA
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David Thompson
Purdue University
Chemistry Dept
560 Oval Drive
West Lafayette, IN 47907, USA
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Richard Tilley
Victoria University of Wellington
Chemical & Physical Sciences
SCP3, Laby Bldg, PO Box 600
Wellington, 6012, New Zealand
[email protected]
345
Sandra Tobias
Merck Research Labs
770 Sumneytown Pike, WP14-2157
[email protected]
Ai Tee Tok
Institute of Chemical & Engineering
Sciences
Crystallisation and Particle Science
One Pesek Road, Jurong Island
627833 Singapore
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Hidetoshi Tomita
FUJIFILM
1740 Technology Drive, Suite 490
San Jose, CA 95110, USA
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Muhammet Toprak
Royal Institute of Technology
Functional Materials, MAP
Isafjordsgatan 24
16440, Stockholm, Kista, Sweden
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Diem Thuy Thi Tran
Invitrogen Dynal AS
Svelleveien 29
2004, Lillestrom, Norway
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Dieter Trau
(NUS)
Bioengineering Div
7 Engineering Drive 1
117574 Singapore
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Carl Tripp
University of Maine
Chemistry Dept
ESRB/Barrows Hall
Orono, ME 04469, USA
346
[email protected]
Dimitris Tsoukalas
National Technical University of
Athens
School of Applied Sciences
9 Heroon Polytechneiou
15780, Zographou, Greece
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Hsien-Hsin Tung
Merck Research Labs
770 Sumneytown Pike
[email protected]
Alexander Türke
Fraunhofer IPMS
Maria-Reiche-Str 2
01109, Dresden, Germany
[email protected]
Rein Ulijn
University of Manchester
Materials Science Centre
Grosvenor Street
Manchester, M1 7HS, United
Kingdom
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Neal Vail
Kinetic Concepts, Inc
6203 Farinon Drive
[email protected]
Maiby Valle-Orta
Universidad Nacional Autónoma de
México
Ciudad Universitaria
Ave Universidad 3000
Coyoacán, 04510, México DF,
México
[email protected]
Nancy Van Suetendael
Florida Institute of Technology
150 West University Blvd
Melbourne, FL 32901-6975, USA
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Richard Vanfleet
Brigham Young University
Physics and Astronomy
N241 ESC
Provo, UT 84602, USA
[email protected]
Chandra Vargeese
Merck & Co, Inc
PO Box 4, WP14-3
[email protected]
America Vazquez-Olmos
Universidad Nacional Autonoma de
Mexico
Laboratory of Materials and
Nanotechnology
Av Universidad 3000 AP 70-186
Mexico City, 04510, Mexico
[email protected]
Orlin Velev
North Carolina State University
Chemical & Biomolecular
Engineering
EB1, 911 Partners Way
Raleigh, NC 27695-7905, USA
[email protected]
Krassimir Velikov
Unilever Food & Health Research
Institute
Olivier van Noortlaan 120
3133 AT, Vlaardingen, Netherlands
[email protected]
Dmitri Vezenov
Lehigh University
Chemistry Dept
6 East Packer Avenue
[email protected]
Chi-Hwa Wang
Department of Chemical &
Biomolecular Engineering
4 Engineering Drive 4
117576, Singapore
[email protected]
Howard Wang
Binghamton University, SUNY
Mechanical Engineering
PO Box 6000
Binghamton, NY 13902-6000, USA
[email protected]
Hui Wang
UOP LLC
50 East Algonquin Road
Des Plaines, IL 60017, USA
[email protected]
Huiliang Wang
Beijing Normal University
College of Chemistry
19, Xinjiekouwai Street
Haidian District
Beijing, 100875, China
[email protected]
Jian-Ping Wang
University of Minnesota
EE 4-173, 200 Union Street
Minneapolis, MN 55455, USA
[email protected]
Qi Wang
Agriculture & Agri-Food Canada
98 Stone Road West
Guelph, N1G 5C9, Ontario, Canada
[email protected]
347
[email protected]
Weimin Wang
Merck & Co, Inc
PO Box 4, WP14-3
[email protected]
Shigeru Watanabe
Kochi University
Applied Science Dept
2-5-1 Akebono-cho
Kochi, 780-8520, Japan
[email protected]
Achim Weber
Fraunhofer IGB
Nobelstr 12
70569, Stuttgart, Germany
[email protected]
Alexander Wei
Purdue University
Chemistry Dept
560 Oval Drive
West Lafayette, IN 47907-2084,
USA
[email protected]
Xian-Wen Wei
Anhui Normal University
Chemistry & Materials Science
No. 1 East Beijiing Road
Wuhu, 24100, Anhui, China
[email protected]
Clemens Weiss
University of Ulm
Organic Chemistry III
89081, Ulm, Germany
[email protected]
Sascha Welz
Nalco Company
1601 West Diehl Road
Naperville, IL 60563, USA
348
Yvonne Williams
Trinity College Dublin
Our Lady’s Children’s Hospital
Crumlin
12 Dublin, Ireland
[email protected]
Mitchell Winnik
University of Toronto
80 St. George Street
Toronto, Ontario, Canada
[email protected]
Solveig Winther
Haldor Topsøe A/S
Nymøllevej 55
2800, Kgs. Lyngby, Denmark
[email protected]
Stanislaus Wong
Brookhaven National Laboratory
Stony Brook, SUNY
79 Cornell Avenue
Upton, NY 11973, USA
[email protected]
[email protected]
Hyun-Yool Woo
Inha University
Nano-Systems Engineering, 2N 569
253, Yonghyun-dong, Nam-gu
Incheon, 402-751, South Korea
[email protected]
Aiguo Wu
Northwestern University
Radiation Oncology
303 East Chicago Ave, Ward Bldg
13-002
Chicago, IL 60611, USA
[email protected]
Yu-Jui Wu
Ming-Hsin University of Science &
Technology
Optoelectronic System Engineering
No. 1, Xinxing Road, Xinfeng
[email protected]
Research Institute of Industrial
Science & Technology
Nanotechnology Research
PO Box 135
KyungBook-do, Pohang City
790-330, South Korea
[email protected]
Kevin Wyndham
Waters Corporation
34 Maple Street
Milford, MA 01757, USA
[email protected]
Hong Yang
206 Gavett Hall
[email protected]
Chunye Xu
University of Washington
Mechanical Engineering
PO Box 352600
Seattle, WA 98195, USA
[email protected]
Ren Xu
Beckman Coulter Inc
11800 SW 147th Avenue, MC 32B13
[email protected]
Nguyen Thi Xuyen
Sungkyunkwan University
Center for Nanotubes &
Nanostructured Composites
300 Cheoncheon-dong, Jangan-gu
Suwon, 440-746, Gyeonggi-do,
South Korea
[email protected]
Yoshinori Yamanoi
The University of Tokyo
Chemistry Dept
7-3-1 Hongo, Bunkyo-ku
[email protected]
Choong-Jin Yang
Yadong Yin
University of California, Riverside
Chemistry Dept
Chemical Science Bldg
Riverside, CA 92521, USA
[email protected]
Kui Yu
National Research Council Canada
Steacie Institute for Molecular
Sciences
100 Sussex
Ottawa, K1A 0R6, Ontario, Canada
[email protected]
Wan Soo Yun
Standards & Science
Nanodevice Group
One Doryong-dong, Yuseong-gu
[email protected]
Betina Giehl Zanetti-Ramos
Universidade Federal de Santa
Catarina
Campus Universitário, Trindade
Av Dep Antōnio Edu Vieira, 1020
Apto 502A – Pantanal
Florianópolis, 88040-001, SC, Brasil
[email protected]
349
Lei Zhai
Chemistry Dept/NanoScience
Technology Center
[email protected]
Tao Zheng
Avon Products, Inc
One Avon Place
Suffern, NY 10901, USA
[email protected]
Ying Zheng
University of New Brunswick
15 Dineen Drive
Fredericton, E3B 5A3, NB, Canada
[email protected]
Chuan-Jian Zhong
SUNY Binghamton
Chemistry Dept
Vestal Parkway East
Binghamton, NY 13902, USA
[email protected]
Christian Zink
Laboratory for Surface Science &
Technology
ETH Zurich
Wolfgang-Pauli-Str 10
HCI E 463.2
8093, Zürich, Switzerland
[email protected]
Shengli Zou
Chemistry Dept
4000 Central Florida Blvd
[email protected]
350
Eugene Zubarev
Rice University
Chemistry Dept, MS-60
6100 Main Street
Houston, TX 77005, USA
[email protected]
351
352
Notes
353
Notes
354
Notes
355
Notes
356
Notes
357
Notes
358
Receipt
This receipt acknowledges payment of _______________________
from __________________________________________________
by ____________________________________________________
for the conference registration fee for Particles 2008 held 10-13 May
2008 at the Wyndham Resort Hotel, Orlando, Florida, USA
________________________________________________
On behalf of:
265 Clover Street
EIN No. 16-1565388
Tel: 1-585-288-5913
Fax: 1-585-482-7795
359

Particles 2008 - nanoparticles.org

Transcription

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