cellulose microfibrills and nanotechnologybiorefinery.utk.edu/ciber/portugal_nanocellulose.pdf ·...

CelluloseMicrofibrills and Nanotechnology

Art J. Ragauskas

Institute of Paper Science and TechnologySchool of Chemistry and Biochemistry

Georgia Institute of Technology

World Pulp ProductionMillion metric tons

010203040506070

U.S.A. Canada Sweden Finland Brazil Chile N.Z.

1995 2002Source: Pulp & Paper International,

Paperloop.com

Cellulosics - TrendsNewsprint capacity fell 1.3% in 2003,decline another 2.8% in 2004lowest since 1989.

Bye bye Paper Tickets TICKETLESS travel will become a global reality by the end of 2007- IATA

•Improved Operations

•Fiber Engineering•Fillers

•New Products

NanoCellulosic Structures

m

10 µm

1 µm

10 nm

1 nm

100 µmmm

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O-Cellulose

OH

OH

O

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O-Cellulose

OH

OH

O

0

20

40

60

80

100

120

140

E-Glas

sHem

p

Flax

Jute

Sisal

CoirCott

on

Nanoc

ellulo

se W

hiske

rsDou

glas F

ir

Pond

erosa

Pine

StiffnessSpecific Stiffness

approx. 100Carbon Nanotubes400 - 700

NanocelluloseWhiskers

approx. 500Fully Exfoliated Clay100 - 400Fumed Silica25 - 300Graphite

4Paper Fibersapprox.1

Surface Area m2/gE-Glass Fibers

Cellulosics StructureBackground Native

Cellulose Iα and Iβ

Chains are parallel; Differences due to orientation of Cellulose sheets

• I – IV Polymorphs• Amorphous• Paracrystalline

Cellulose II:

anti-parallel

Elementary fibril

Microfibril

• Acid Hydrolysis Technique

Bleached softwood kraft pulp Cellulose + H2SO4

Stirred at 45 C, 45 min ~ 1 hourDilute with waterCentrifuged, wash and neutralizeRe-disperse with ultrasonicationAllowed to stand over a mixed bed resin for 48 hThe mixture was centrifuged and the supernatant was filter through filter paper. The filtrate was colloidal nanowhisker suspension


Cellulase from Trichoderma reesei

0 5 10 15 20 253

4

5

6

7

8

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

ΙβCellulose: Iβ

0

20

40

60

80

100

0 10 20 30 40 50

Hydrolysis Time, h

Glu

cose

yie

ld, %

Pulpavicel

Cellulose: Iα

0 5 10 15 20 252.5

3.0

3.5

4.0

4.5

5.0

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

ΙαCellulose: Iα

Enzymatic Hydrolysis of Cellulosics

• Cellulolytic filamentous fungus

cellobiohyrolasesendoglucanasesβ-glucosidasesNREL

0

20

40

60

80

100

0 10 20 30 40 50

Hydrolysis Time, h

Post

-hyd

roly

sis p

erce

ntag

e, %

avicelpulp

Enzymatic Hydrolysis of Cellulosics

0 5 10 15 20 25

33

34

35

36

37

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

Para-crystallinePara-crystalline

0 5 10 15 20 25

46

48

50

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

AmorphousAmorphous

AFM images of nanowhisker


Nanocellulose Whisker Composite Films

Polystyrene (average Mw ~280,000 ) solution in THF (5% w/w) Dry nano whiskersPolymer films were prepared by solution casting into molds. 3% nanocellulose whiskers were added into polymer solution, sonificated and then solvent cast into moldsFilms was of a thickness of 50~110 µm


Nanocellulose Whisker:Polystyrene Composite Film

Polystyrene /whisker film

Mechanical tests were carried out on an Instron 4400R4.5 inch length * 15 mm width

+ 23%+ 11%+70%Polystyrene/NC whisker

46.51.38.9Polystyrene

Modulus (MPa)

Elongation, %

TEA*, J/m2

*: Tensile energy absorption.

Preliminary Physical Properties


NanoCellulosic StructuresNanocellulose Whisker

Acrylic Acid Composite Film

Experimental Method

• Dow acrylic latex, solids 50%• Add cellulose whiskers or hardwood bleached

kraft pulp• Mixture cured at RT• Initial film dried 50 ˚C for 2 days.

0

50

100

150

200

250

300

350

0 5 10 15 20Filler,%

Stra

in, %

WhiskerPulp Fiber

NanoCellulosic StructuresNanocellulose Whisker:Acrylic Acid Composite Film

0

2

4

6

8

10

12

14

0 5 10 15 20Cellulose, %

Tensile strength, MPa

WhiskerPulp Fiber

0

1000

2000

3000

4000

0 5 10 15 20

Filler, %

TEA, J/m2

WhiskerPulp Fiber

Nanocellulose Whisker:Acrylic Acid Composite Film


Latex Film 20% Cellulose Whiskers:Latex Film

20

25

30

35

40

0 5 10 15 20 25

Whisker content, %

Contact angle

5% Cellulose Whiskers:Latex Film

Nanocellulose Balls

• SW ECF bleached kraft pulp• Refined to 20-mesh • Swell fibers with 5M NaOH followed by DMSO• Sonicate cellulose with HCl – H2SO4 75 oC • Wash with water, purify by centrafugation• Sonicate cellulose with HCl – H2SO4 75 oC• Wash with water, purify by centrafugation

Nanocellulose Balls

First nanocellulose procedure able to provide practical control of particle sphere dimensions!!

050

100150200250300350400450500

0 2 4 6 8 10 12

Time (hour)

Siz

e (n

m)

020406080

100120140160180

0 1 2 3 4 5

Time (hour)

Siz

e (n

m)

Nanocellulose Balls

Nanocellulose Balls – 76 nmAFM Images

Nanocellulose Balls

S-800 FE SEM

180 nm balls

76 nm balls

Nanocellulose Crystallinity Results 13C-CP/MAS NMR Analysis

0.7050 – 100 nm Nanocellulose BallsCellulose II

0.65300 – 500 nm Nanocellulose BallsCellulose II

0.61Original pulp – Cellulose 1

Crystallinity index

C-1

C-4

C-2, 3, 5

C-6

Nanocellulose Whisker-Balls:Acrylic Acid Composite Film


Latex Film

5% Cellulose Balls:Latex Film 5% Cellulose Whiskers:Latex Film

0200400600800

100012001400

TEA

Latex nanoball whisker acacia

Pathforward• Nanocellulose balls

– Derivatives to be used for superabsorbers – viscosity modifiers– Artificial blood/drug delivery– Cosmetics– Template for Nanospheres

• Nanocellulose whiskers– Composites with plastics– Composites with natural polymers– In-situ polymerization

Nano-Enhanced Paper and BoardIPST@GT Research Accomplishments:

Nanocellulose Additives for Innovative Composites

1. Disperse Plastic Resin

2. Heat Press – PMMAPolymethyl methacrylate

Fiber 10% 30% PMMA PMMA

ECF SW Kraft

30

35

40

45

50

55

60

65

70

75

80

0% PMMA 10% PMMA 30% PMMA

Con

tact

Ang

le (d

egre

es)

Micro-sized PMMANano-sized PMMA

60 nm PMMA5-100 micron PMMA

Composite Fabrication

• Fiber and PMMA powder was mixed in a blender.

• Fiber/PMMA mixture was compression molded at 170°C for 10 minutes.

• Composite specimen was 1.24” in diameter and 1mm in thickness.

ECF Pulp

SEM

Nano PMMA, 10%Course PMMA, 10%

SEM

Course PMMA, 30% Nano PMMA, 30%

SEM

Polystyrene-ECF Kraft Composite

Nano-Enhanced Paper: CoatingsApplication of Polyelectrolyte Coating TechnologiesLayer-by-Layer Self-Assembly

General Considerations:General Considerations:

•• Assembly via electrostatic and HAssembly via electrostatic and H--bond interactionsbond interactions•• Aqueous ProcessingAqueous Processing•• Process Parameters:Process Parameters:

•• pH; salt concentrationpH; salt concentration•• Polymer charge/DPPolymer charge/DP

•• Wide range of materials can be employedWide range of materials can be employed

Nano-Enhanced Paper: Coatings

CNH2O

n

n

N+

Cl-

n

NH3+ Cl-

PolymethylAcrylic acid

Polyallylamine hydrochloride

Polysulfonate styrene Polydimethyldiallylammonium chloride

Poly(acrylamide)

Typical Polymers Employed for Self-Assembly

CO- H+O

n

n

SO3- Na+

CO- H+O

n

CH3

Poly(acrylic acid)

Positive Neutral Anionic


++++++

Current Studies n

NH3+ Cl-

PAH

_ _ _ _ _

n

N+

Cl-

PDDA

Montmorrilonite Kaolin


n

NH3+ Cl-

PAH

n

N+

Cl-

PDDAMontmorrilonite Kaolin

8 Bilayers PDDA/Montmorrilonite

8 Bilayers of PDDA/Kaolin

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

250 350 450 550 650 750 850Wavelength (nm)

Abs

orba

nce

Number of bilayers87654321

Nano-Enhanced Paper: CoatingsCurrent Studies

n

NH3+ Cl-

Initial Fibers 8 Bilayers of PAHKaolin


n

NH3+ Cl-

8 Bilayers of PAHKaolin

0.0

1.0

2.0

3.0

4.0

5.0

6.0

4 bilayers 8 bilayers 12 bilayers 16 bilayers

Wet

Ten

sile

Inde

x (N

m/g

)

0

10

20

30

40

50

60

70

80

90

100

110

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Number of Layers

Con

tact

Ang

le (d

egre

es)

Nano-Enhanced Paper: CoatingsCurrent Studies

n

NH3+ Cl-

n

N+

Cl-

Bilayers of PAH/Kaolin

Ongoing Studies• Alternative L-b-L technologies • Enhance hydrophobic effect• Utilize other nanomaterials• Unique optical properties• Functional barrier properties

Where Is This All Going?"Give me a lever, a fulcrum, and place to stand and I will move the world."

Archimedes ∼200 BC

Forest Products CommunityInnovative Products“Nano-Inside”

Societal Demand forCarbon Neutral, Environmentally Friendly, Renewable and SustainableManufacturing Technologies

Consumer DemandValue Added

Products &

Materials

More Relevant Today!!!Leveraging: Nano Research and Development

Partnership Industry, Universities,

Government

[email protected]

[email protected]

AcknowledgmentsGA Research AllianceNational Science FoundationIPST Industry Consortium

cellulose microfibrills and nanotechnologybiorefinery.utk.edu/ciber/portugal_nanocellulose.pdf ·...

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