denilson da silva pereza and alain dufresneb

Overview of Cellulose Nanocrystals and Nanofibres: The Science and Technology –A European Perspective

Denilson da Silva Pereza and Alain Dufresneb

a)FCBA – New Materials Division; b) INP Grenoble PAGORA

OECD Conference on Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led GrowthOECD Conference Centre - Paris ,July 15th-17th 2009.

Overview of Cellulose Nanocrystals and Nanofibres: The Science and Technology OECD Conference on Potential Environmental Benefits of Nanotechnology- July 15th-17th 2009 - DdSP - 2

• BackgroundWhy cellulose micro- and nanofibres ?From trees to cellulose molecular levelCellulose microfibrils and nanocrystalsCellulose biosynthesis and polymorphism

• Cellulose micro/nanofibres and nanocrystalsLaboratory scale productionCharacterization and applicationsScaling-up technology : Main challenges

Outlines


1) Same reasons as for cellulosic fibres…

Non-fossil, low density, high specific strength and modulus, renewability, biodegradability, high availability in a variety of forms, flexibility, non abrasive nature, non-toxicity, easiness to handle, moderate ability for surface modification, possibility to generate clean bioenergy at endlife, no competition with food (for forestry fibers), relative low cost.

☺

Hydrophilic character : poor adhesion and dispersion in non-polar matrix, high moisture absorption, limited thermal stability : low permissible temperatures of processing and use, very high fiber-to-fibre affinity, (early) biodegradability.

Why cellulose micro- and nanofibres ?


2) To reduce intrinsic heterogeneity and create almost defect-free structuresKnobby swelling along flax fibers Hardwood fibres

Why cellulose micro- and nanofibres ?

Dufresne et al., 1997

Microfibrillated cellulose

Habibi et al., 2008

Cellulose nanocrystals(Lampke, 2001) (FCBA, 2009)


Cellulose crystals are potentially stronger than steel and similar to Kevlar®

Experimental Young’s modulus : 137 GPaTheroretical Young’s modulus : 167.5 GPa

Why cellulose micro- and nanofibres ?3) To create high performing bio-based materials


trunk

timber

growth ring

fibers

cell wall

microfibrils

molecule

10°-102

10-2

10-3

10-6

10-9

10-10

macrofibrils 10-8

10°-101(m

eters)

From trees to cellulose molecular level…


Cell wall structure

Paroi primaire

Couche S1

Couche S2

Couche S3

Lumen

Lamelle moyenne

Paroisecondaire

Sub-layers Thickness (μm)

Number of MF layers

MFA

Primary 0,05 – 0,1 – – Secondary S1 0,1 – 0,3 3 – 6 50 – 70

Secondary S2 1 – 8 30 – 150 5 – 30 Secondary S3 < 0,1 < 6 60 – 90

ML 0,2 – 1,0 –

Stratified and multi-axial structural systemStratified and multi-axial structural system


Cellulose biosynthesis

• Cellulose is biosynthesized by terminal complexes (rosettes) embedded in the plasma membrane

• The number of cellulose chains composing the rosettes determines the size of the microfibrills (usually 18-36 chains in higher plants)

• It explains the parallel orientation of cellulose chains in nature (thermodynamically defavorable)

http://www.as.wvu.edu/~cbarth/BIOL%20754%20Lecture%202%20080821_Cell%20walls%20handouts.pdf


Supramolecular structure of cellulose microfibrils

http://www.as.wvu.edu/~cbarth/BIOL%20754%20Lecture%202%20080821_Cell%20walls%20handouts.pdf

Sugiyama et al. (1991), Macromolecules 24, 4168-4175

• Co-existence of crystalline and amorphous cellulose

Amorphous domains ? Or…Surface chains + minor crystal defects ?


Cellulose polymorphism

Isogai, Cellulosic Polymers, Blends and Composites, Allomorphs of cellulose and other polysaccharides, 1-24, 1994.

Cellulose I : Native celluloseParallel chain arrangement

Cellulose II : Recrystallized celluloseAnti-parallel chain arrangement

Cellulose III : Swollen cellulose, different orientation of C6Chains arrangement depends on initial cellulose allomorph

Cellulose IV (?)


Micro/nanofibrillated cellulose

• The isolation of crystalline zones asks for a combination of two characteristics prerequisites :

Controlled (bio-)chemical pretreatments to destroy the molecular bonds whereby microcrystals are hinged together in a network structure

Appropriate use of mechanical energy to disperse a sufficient amount of the unhinged microfibres in the aqueous phase

• The amorphous regions act as structural defects where the cleavage of the microfibrils into short monocrystals takes place

Samir et al., (2005) Biomacromolecules, 6 (2), 612 –626.

Marchessault et al. (1961) J Colloid Sci.16,327-344.


• Chemical pre-treatmentsControlled acid hydrolysis Alkaline swelling and/or hydrolysisSurface cellulose chemical modifications

• Enzymatic pre-treatmentsCellulasesHemicellulases

• Mechanical treatmentsFibers refining/beating/grinding

“Homogenizers”

Micro/nanofibrillated cellulose


Enzymatic treatments

XylanasesXylanasesMannanasesMannanases

Lignine

Hémicelluloses

Cellulose

ENZYMES AUXILIAIRESENZYMES AUXILIAIRESFéruloyl esterasesFéruloyl esterases……

ENZYMES ENZYMES LignolytiquesLignolytiquesLaccases, Laccases, MnPMnP,…,…


CellulasesCellulases


Lignine

Hémicelluloses

Cellulose





Lignine

Hémicelluloses

Cellulose





Endoglucanases: cleaves internal β-1,4-glucosylic bonds on cellulose molecule

Exoglucanases: cleaves ends of cellulose chains to formoligosaccharides (e.g. cellobiose)

β-glucosidases: hydrolyzes soluble oligosaccharides to glucose

Shaw J. (2006) Executive Office of Environmental Affairs Workshop http://www.mass.gov/Eoeea/docs/doer/alternative_fuels/cew061108-dartmouth-shaw.pdf

Tapin-Lingua, S., Fiche Inforamtions Forêts 753, 2007, AFOCEL.


Micro-/nanofibrillated cellulose – Homogenizers



Sidduqui et al., 2008 International Conference on Nanotechnology for the Forest Products



Source : Masuko (Japan)

Source : Cavitron (Germany)

Sidduqui et al., 2008 International Conference on Nanotechnology for the Forest Products


Selective oxidation of hydroxymethyl group at C6 position into carboxylic groups

Main advantages

High selectivity

Aqueous system

Grafting from COOH possible

NaClO

NaCl

NaBr

NaBrO

N OH

N O

N O

.

+ OOH

OHOH

O

OONa

OHOH

OO OH

* 2,2,6,6-tetramethyl-piperidine-1-oxil

de Nooy et al. Recl. Trav. Chim. Pays-Bas, 113, 165-166 (1994); Carbohydr. Res., 269, 89-98 (1995); Macromolecules, 29, 6541-6547 (1996).Chang and Robyt. J. Carbohydr. Chem., 15(7), 819-830 (1996).Isogai and Kato. Cellulose, 5, 153-164 (1998). Tahiri and Vignon. Cellulose, 7, 177-188 (2000). Da Silva Perez et al. Biomacromolecules, 4, 1417-1425 (2003).

Chemical modification


Micro-/nanofibrillated cellulose Visual aspect

1 passes(400 µm)

+ 6 passes(200 µm)

+ 12 passes(200 µm)


Micro-/nanofibrillated cellulose Microscopic characterization

• Optical microscopy

• Transmission electronic miscrocopy


Homonoff et al., 2008 International Conference on Nanotechnology for the Forest Products

Micro-/nanofibrillated cellulose II


• Swelling of cellulose in liquid NH3 (or other amines), a simple way to increase crystalline cellulose accessibility.

• Ammonia enters the cellulose crystals as guests and modify the conformation of the hydroxymethyl groups

• Upon release of guest molecules, CH2OH groups remain distorted

“Activated state”.

• Cellulose III allomorphs formation : Essentially a solid state process Keep the integrity of the cellulose microfibrils while achieving substantial decrystallizationReorganization of intra-crystalline hydrogen bonds

Micro-/nanofibrillated cellulose III


• Main features concerning the gel fractionNH3-treatment improves the production of gel fraction.

Gel fraction amount varies from 2 to 76 % depending on :

Cellulose originCellulose allomorph (III or III)Extent of oxidationInitial form of samples


Da Silva Perez et al., 2008 International Conference on Nanotechnology for the Forest Products


• Transmission Electronic Microscopy (TEM)

Gel fraction is essentially composed of nano-fibres of length varying between 60 and 250 nm and width between 10 and 20 nm


Da Silva Perez et al., 2008 International Conference on Nanotechnology for the Forest Products


Paper applicationsBarrier


Paper applicationsPhysical properties

Gregersen, Ǿ, 2008, Recent advances in fibrilar nanocellulose research


Nano-biocomposites applications

Azizi Samir et al., 2004

5

6

7

8

9

10

150 250 350 450 550

Temperature (K)

log

(E'/P

a)

Transmission electron micrographs of a dilutesuspension of sugar beet cellulose microfibrils: (a) CMF, (b)

CMF20, and (c) CMF60.

● Poly(S-co-BuA)● CMF● CMF20● CMF 60

6 wt%

1811.531P6CMF60

1021.755P6CMF20

326.3114P6CMF

> 30000.180.2Matrix

εB (%)σB (MPa)E (MPa)Sample

Microfibrillated cellulose x whiskers


20 nmvalonia tunicin

ramie wood Primary cellwall

Cellulose Nanocrystals (whiskers)

Bleached raw-material

Hydrolysis treatment (H2SO4, 60°C, 20 min)

Neutralization, washing, centrifugation, dialysis,

sonication

Disintegration in water


L = 0.5-2 µmd = 15 nmL/d = 67

Favier et al., 1995

Tunicate

L = 150-300 nmd = 5 nmL/d = 45

Helbert et al., 1996 Ebeling et al., 1999

L = 100-200 nmd = 15 nmL/d = 10

Courtesy of A. Dufresne - PAGORA



Sisal

L = 250 nmd = 4 nmL/d = 60

Garcia et al., 2006

Sugar Beet

L = 210 nmd = 5 nmL/d = 42

Azizi Samir et al., 2004

200 nm

L = 200 nmd = 7 nmL/d = 29

Habibi et al., 2008

Ramie




Dufresne, Encyclopedia of Nanoscience and Nanotechnology 2nd Edition, in press

Nature Source L (nm) D (nm) Ref.

Cellulose Algal (Valonia) > 1000 10-20 [140,141] Bacterial 100-several

1000 5-10 × 30-

50 [130,133,142]

Cladophora - 20 × 20 [143] Cotton 100-300 5-10 [111,144-147] Cottonseed

linter 170-490 40-60 [148]

MCC 150-300 3-7 [135] Sisal 100-500 3-5 [137] Sugar beet pulp 210 5 [112] Tunicin 100-several

1000 10-20 [139,149]

Wheat straw 150-300 5 [136] Wood 100-300 3-5 [113,124,127,144]

Chitin Crab shell 80-600 8-50 [150-152] Riftia tubes 500-10000 18 [153] Shrimp 50-300 5-70 [154,155] Squid pen 150-800 10 [156]




Scaling-up technology : Main challenges

•Micro/Nanofibrillated celluloseScaling-up of homogenization technologiesReduction of energy consumptionReduction of enzymes consumptionReduction of clogging problemsSimplifying purification processesDevelopment of characterization routine methods Controlling M/NFC reaggregationConcentration/Drying M/NFC (major issue!)Controlling early biodegradabilityExchange water – organic solvents (biocomposites)Reduction of production costsGuarantee of non-toxicity at nano-scaleDevelop new markets



• Cellulose NanocrystalsReduction of chemicals consumption

Find applications for co-products (sugars from hydrolysis)

Simplifying purification process (centrifugation 10000 rpm, dialysis, freeze-drying)Development of characterization routine methods

Concentration/Drying NC (major issue!)

Controlling early biodegradability

Exchange water – organic solvents (biocomposites)

Prove to be more than only “models” for fundamental studies

Reduction of production costs

Guarantee of non-toxicity at nano-scale

Develop new markets



Health-related questions :

Micro/nano scales effect actual risks ? (CNT!) Processing : aqueous / gel media (no actual risks ?)End-products : can M/NFC detach from network ?Modified M/NFC : risks related to the nature of physico-chemical modifications ?

Environment-related questions :

Effluents quality of M/NFRecyclability of M/NFBiodegradability / bioassimilation of M/NFC ?


From science to technology

FundamentalR&D science

AppliedR&D science

Scale-up /Demonstrators

Industry /Markets

Pilot scale

MicrofibrillatedCellulose I

NanofibrillatedCellulose I

Micro/nanofibrillatedCellulose II

Micro/nanofibrillatedCellulose III

Cellulose Nanocrystals ?

FunctionnalisedM/NFCPaper

applications

Nanocompositesapplications


A European perspective


Acknowledgements

• Co-authors and colleagues for the information and material for this presentation

• EGIDE, AGRICE/ADEME, UE for financial support

• NMA staff involved in this research theme

• CERMAV, PAGORA and FCBA staff for nano-fibers analysis

• Professor Mohini Sain for the invitation

denilson da silva pereza and alain dufresneb

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