Cellulose Microfibrills and Nanotechnologybiorefinery.utk.edu/ciber/Portugal_Nanocellulose.pdf ·...
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Cellulose Microfibrills and Nanotechnology Art J. Ragauskas Institute of Paper Science and Technology School of Chemistry and Biochemistry Georgia Institute of Technology
Transcript of 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
NanoCellulosic Structures
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
NanoCellulosic Structures
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
NanoCellulosic Structures
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 Structures
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
NanoCellulosic Structures
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
NanoCellulosic Structures
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
Nano-Enhanced Paper: Coatings
++++++
Current Studies n
NH3+ Cl-
PAH
_ _ _ _ _
n
N+
Cl-
PDDA
Montmorrilonite Kaolin
Nano-Enhanced Paper: Coatings
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
Nano-Enhanced Paper: Coatings
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
AcknowledgmentsGA Research AllianceNational Science FoundationIPST Industry Consortium
