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From Nanocellulose Science
towards Applications
Hans-Peter Hentze
VTT – Technical Research Center of Finland
PulPaper 2010 - June 2nd ’10 - Helsinki
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Agenda
I. A Brief History of Nanocellulose Science
II. Structure-Properties Relationships
III. Towards Applications
IV. Summary & Outlook
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I. A Brief History of Nanocellulose Science
Nanocellulose Science:
Synthesis, modification, characterization &
study of structure-properties relationships
Some Highlights:
1980 1990 2000 2010
Esau (1977)
NFC fibrils First NFC
production &
thickener in
food applications
Turbak / Rayonier /
Daicel (since 1980s)
Cast-iron paperBerglund (2008)
Transparent
NFC compositesNogi (2005)
Transparent
NFC paperYano (2009)
(e.g. Eichhorn et. al, „Review: current international research into cellulose nanofibres and nanocomposites‟
J Mater Sci (2010) 45:1–33)
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Nanocelluloses – A Class of Nanomaterials
Examples of Raw Materials:
Examples of Production Methods:
Top-Down / Bottom-Up
Grinding, Homogenizer, Intensification, Hydrolysis / Electrospinning, Ionic liquids
Wood Bacteria Straw Sugar Beet Banana Potato
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Nanocelluloses – A Class of Nanomaterials
Properties of Nanocelluloses:
Diameter: 5 nm - 500 nm
Length: 10s nm - 100s mm
Specific surface area: 10s - 100s of m2/g
Surface modification: anionic, cationic, grafted, carboxymethylated, etc.
(analogue to cellulose macrofibers)
Main Characterization Methods:
Diameter: AFM / TEM / FE-SEM Lengths: Electron Microscopy / Rheology
Crystallinity: NMR / WAXS Surface properties: IR / NMR / Titration
Surface area: BET
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Deriving Potential Applications
Technology push AND Market Pull as Complementary Drivers:
Technology Push Market Pull
Product Development & Production
- Efficiency:Savings of raw materials & energy
- Productivity:e.g. Runability &new processes
- Added value products & new functionalities
Potentialapplications& production
processes
Science & Fundamental
Research- Synthesis &
modification
- Characterization
- Structure-Properties Relationships
- Demonstrationof new properties
Applied Science &
Technology
Development
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II. Structure-Properties Relationships
Nanocelluloses – Comparison with Related Applied Materials
MACROFIBERS
NANOPARTICLES
POLYMERS /
POLYELECTROLYTES
CNC
MFC
oxidized
NFC
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Structure-Properties Relationships
NFCs as Functional Materials – Identifying potential applications
MACROFIBERS
NANOPARTICLES
POLMERS / POLYELECTROLYTES
Pigments, Fillers, Strength-enhancing additives,
Nanocomposites, Coatings (Packaging),
Functional Surfaces, etc.
Fiber Web Structures
(Paper, Board),
Wood Fiber Composites,
Construction Materials,
Membranes, Filters,
Absorbents, etc.
Rheological Modifiers,
Flocculants (Retention aids),
Binders, Adhesives,
Coatings, etc.
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Identification of Potential Application Areas based on
Specific Properties of Nanocelluloses
III. Towards Applications
Potential Applications Composites
Construction Materials
Porous Materials
Fiber Web Structures
(e.g. Paper & Board)
Coatings
Functional Surfaces
Functional Additives
(e.g. rheological modifiers)
Others …
NFC Properties Natural & renewable
Biodegradability
Biocompatibility
High strength & modulus
High surface area
High aspect ratio
Chemical functionality
(e.g. for modification)
Dimensional stability
Moisture absorption
Thermal stability (~200°C)
Others …
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Composite & Construction Materials
Renewable and Biodegradable Composites
NFC as a strength enhancing additive for renewable
and biodegradable matrix polymers: (e.g. Okubo et. al, JSME Series A 48, 199–204 (2005))
Applications: Packaging, construction materials, appliances,
renewable fibers (Zoppe et al., Appl.Mat.Int., 1996-2004 (2009))
(Juntaro J, et. al (2008)
Adv Mater 20:3122)
Poly(lactid acid)-Sisal composite
with (right) and without (left) NFC
NFC as a binder between
the two organic phases
(improved fracture toughness &
prevention of crack formation)
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Composite & Construction Materials
Transparent Polymer-NFC Nanocomposites
NFC as a transparent and dimensional stable strength-enhancing
additive and substrates (Nakagaito, et. al, MRS Bulletin, 214-218 (2010),
Okahisa et. al, Composites Science and Technology, 1958–1961 (2009))
Application: - Large flexible screens, solar panels, flexible computers
- Paper-like, flexible displays (e.g. textiles by R2R)
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Composite & Construction Materials
Concrete and Cementicious Materials
Strength enhancement of cellular concrete (e.g. ‘Nanocrete Technologies‟)
Application: - Light-weight, foamed, cellular concrete structures
- Crack reduction, combining toughness & strength
(Walther et. al, Nano Letters (2010))
Foamed, cellular NFC-concrete
hybrid materials
Dense, silica-polymer
hybrid materials
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Porous Materials & Fiber Web Structures
Paper & Board Strength Enhancement
Wood fiber web structures – Paper as a porous nanocomposite(e.g. Gardner et. al, J. Adhesion Sci. and Tech. (2008) 545–567,
Eriksen et. al, Nordic Pulp & Paper Research Journal, 299-304 (2008))
NFC increased both:
binding area and binding strength (Stot ~ AB · SB)
Applications:
High strength / high bulk / high filler content paper & board
NFC
Wood fiber Filler
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Porous Materials & Fiber Web Structures
Porous Nanocellulosic Materials for Insulation & Packaging
Highly porous & strong nanocellulose web structures(e.g. Svagan et. al, Advanced Materials, 1263-1269 (2008))
Applications: Cellular Bioplastics, Insulation and Packaging,
(bio)active membranes & filters
X-ray microtomography:
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Porous Materials & Fiber Web Structures
Nanocellulose Scaffolds for Tissue Engineering
Bacterial nanocellulose as biocompatible, highly porous scaffolds(e.g. Bodin et. al, Biomacromolecules, 3697-3704 (2007))
Applications: Bone implants, artificial blood vessels,
stem cell therapy
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Coatings & Functional Surfaces
Nanocelluloses for Coating Applications
Nanocelluloses as barrier materials
Specific advantages: high oxygen barrier, affinity to wood fibers
Disadvantage: Moisture sensitive (hydrophobic compound required)(e.g. Hult et. al, Cellulose (2010))
Application: Food packaging, printing papers
(smooth surfaces, NFC as an organic pigment)
Multilayered coating
with oxygen and water
vapor barrier properties
NFC
Shellac
Paper
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Functional Additives
Nanocelluloses as Flocculants and Retention Aids
Functionalized nanocelluloses as retention aids, combing
a large hydrodynamic radius and high collision efficiency(e.g. Link Magazine 2008/2)
Applications: Retention aids, wet web strength additives,
dry strength additives, water-treatment
Cationic nanocelluloses
as flocculants e.g. retention aids
NFC
Fiber/fines/filler
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Functional Additives
Nanocelluloses as Rheological Modifiers
NFC as a thixotropic, biodegradable, dimensionally stable
thickener (stable against temperature and salt addition)
Low-calories food applications
Thickener in cosmetics
Pharma (tablet binder, diagnostics: bioactive paper)
Pickering stabilizer for emulsions & particle stabilized foams
Paint formulations
Enhanced oil recovery
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Other Applications
Manifold Opportunities for Other Applications
Flexible Energy Storage Devices (Batteries, supercapacitors)
Adaptive, biomimetic nanocomposites
(e.g. mimicking sea cucumber dermis)
(Capadona JR et. al, (2008) Science 319:1370)
(e.g. Nyström, Nano Letters (2009))
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Additional Aspects of Nanocellulose Applications
Multiscale Modelling of Nanocellulosic Materials
Optimized product properties & target-directed development
Life Cycle Analysis (LCA)
Quantification of eco-efficiency and sustainability factors
Nanosafety
Risk assesment of nanomaterials ongoing
Highest potential risk: Inhalation of airborne nanoparticles
Experience in food applications and medical applications
of nanocelluloses: no implications
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IV. Summary & Outlook
Nanocelluloses resemble a class of novel nanomaterials
Wide properties range of different modified and
non-modified nanocelluloses
Nanocellulose applications are based on the same principles:
Design of nanostructure, interfacial interactions,
& assembly into systems
Specific advantages of nanocelluloses:
Abundant, natural nanomaterials
Renewable, biodegradable & biocompatible
High strength & modulus
High aspect ratios & high surface areas
Chemical functionality & modification
Dimensional Stability
… and combinations of those !
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Summary & Outlook
Additional Long-term Perspectives for Papermaking, e.g.:
Wood-free papermaking:
- Use of NFC e.g. from bio-residues and other raw materials
instead of wood fibers
- NFCs show similar properties, independent from raw
materials sources (Abe et. al, Cellulose (2009) 16:1017–1023)
Water-free papermaking:
- Paper-like NFC web structures might be produced
from volatile solvents (e.g. alcohol) or dry processes
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Nanochemistry: What Is Next?Geoffrey A. Ozin et. al
“We believe that the major conceptual contribution of
nanochemistry … lies in the interdisciplinarity that it
has imprinted. … This transformation can probably be
considered as the greatest success story of
nanochemistry, as it has brought the science, engineering,
biology … together in a unique way to dream up and
create new materials that solve problems.”
small 2009, 5, No. 11, 1240–1244
“ There is an increasingly common feeling that nanoscience
has not yet delivered on its initial promises, especially from
a technological perspective. ”
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Thanks for your attention !