What is nanocellulose ? Prof. Janne

Transcription

What is nanocellulose ? Prof. Janne
What is nanocellulose ?
Prof. Janne Laine
Helsinki University of Technology, 14.2.2008
From cellulose (wood) fibres to
nanofibrillated cellulose
Fibres
• Width 30-40 μm
• Length 1-3 mm
Fibrils
• Width 5-30 nm
• Length over 1 μm
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How to make nanofibrillated cellulose
from wood pulp ?
Nanofibrillated
Cellulose
Masuko refiner
Microfluidizer
Homogenisator
The production of nanofibrillated cellulose is based on
disintegration of cellulose fibres by combining
mechanical treatment with chemical (or entzymatic)
treatments
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low energy consumption
good quality (homogenous material)
a large variety of functionalities
good processability
Treatments by tailor-made polymers
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Stable dispersion
Controlled rheology
Surface modification of nanocellulose
Improved compatability between
different materials
Formable, light, tough, smooth and
other novel properties and structures
Excellent paper
surface
Formable, tough,
light composites
Ahola et al 2007
(E≈ 6
GPa)
Henriksson 2008
Lindström, Winter 1988
Superior paper strength
Novel structures
Ahola et al 2007
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Novel Functional materials
Ti2
Conducting cellulose
materials
• other metals
• magnetic materials
TiO2 layer makes MFC
photocatalytic active
•1% NFC: ~ 6 x 10-2 S/cm3
•2%NFC: ~ 5 x 10-3 S/cm3
•5%NFC: ~ 8 x 10-4 S/cm3
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Chemistry of Materials,
2007, revising
Silvennoinen et al.
Numerous, high sophisticated
characterization techniques are needed!
Dimensions and network structure
ƒ AFM
ƒ TEM, SEM
ƒ BET
ƒ Particle size analyzers
ƒ Dynamic rheology
ƒ SAXS
ƒ DMA
Chemical and surface chemical properties
ƒ Charge measurements
ƒ Chemical composition, XPS
ƒ Wettability
ƒ Adsorption properties
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BACK TO PROGRAMME
What is nanocellulose ?
Preparation of nanofibril
Products
It is a natural nanomaterial that provides a large range
of possibilities to obtain superior material properties for
different end-products
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