Washless Multi-Nano-Layered Fiber Preparations · Zeta-potential - mv add PAH add PAH again add PAH...
Transcript of Washless Multi-Nano-Layered Fiber Preparations · Zeta-potential - mv add PAH add PAH again add PAH...
St. Louis, MO, June 25-27, 20087
Washless Multi-Nano-Layered Fiber Preparations
G. Grozdits1,5 Y. Lvov2,5 Qui Xing2, Manginal Agarwal2, Mark D. Gibson3 and Jon Chapman4
1 Research Assistant Professor, School of Forestry, 2Professor and Research Group Leader, Doctoral Candidate, Research Associate at the Institute of Micromanufacturing 3Professor & Director School of Forestry at Louisiana Tech University, Ruston, LA, 4Quality Control Supervisor,
Smurfit-Stone Paper Corp. Hodge, LA, 5Nano Pulp & Paper LLC, Ruston, LA
Session 12 – 9:00 – 10:30 AM Thursday2008 International Conference on Nanotechnology for the Forest
Products IndustrySt. Louis, Missouri June 25 – 27, 2008
Layer-by-Layer AssemblyAlternate Adsorption of Oppositely Charged
Linear Polyions and Nanoparticles
The LbL-assembly regimes for more than 50 compounds were established at IfM (using the “dipping automate” equipment).
Development of Nano-LbL-selfassemblies1992-1999
G.Decher, H.Moehwald, Y.Lvov,M.Rubner, J.Fendler, J.Schlenoff, P.Hammond, N.Kotov, T.Kunitake, F.Caruso, G.Sukhorukov
References: G. Decher Science, 1997, v.227, 1232 “Fuzzy nanoassemblies: Toward layered multicomposites” Y. Lvov, K. Ariga, T. Kunitake, J. Am. Chem. Soc., 1995, v.117, 6117-6122 "Assembly of multicomponent protein films by means of electrostatic layer-by-layer adsorption"
St. Louis, MO, June 25-27, 20087
Are the LbL molecular layers really separated in the LbL multilayer?
Do we create a composite layer with new “combined” properties?
St Louis, MO, June 25-27, 2008
Nano assemblies change cellulose fiber properties
Confocal images Zeta (ξ) potential approximation
St Louis, MO, June 25-27, 2008
PAH - Poly(allylamine hydrochloride)
PSS – Poly(styrenesulfonate)
Presence of Subsequent layers, labeled PAH (green), labeled PSS (red)
Fiber surface properties change after subsequent PAH and PSS nano-layer depositions
History and Development ofThe Louisiana Tech Nano Pulp and Paper Initiative
Established LbL nanocoating feasibility in clean-lab conditions
1. Used positive & negative LbL treated unbeaten bleached Kraft commercial pine pulp
2. Used unbeaten bleached Kraft commercial pine pulp with LbL treated broke and fines in clean lab conditions
3. Used machine stock with LbL treated mill broke, LbL treatment in DI water
4. Used machine stock with LbL treated mill broke, LbL treatment in mill process water
5. Use of 100 % recycled OCC (old corrugated containerboard) pulps, in a limited pilot plant study, done at USDA-FS-FPL at Madison, WI. Refining after coating, Effect of Washing, and Partial LbL Coating
6. Development of “Washless LbL Process” for pulp fibers
St Louis, MO, June 25-27, 2008
Progress in Layer-By-Layer Nanocoating of Cellulosic Fibers From Clean Lab Conditions to Mill Process Samples
0
40
80
120
160
200Te
nsile
Inde
x N
•m/g
1 2 3 4
Orginal pulp
Orginal+positivepulp
Orginal+negativepulp
Positive+negativepulp
In Clean Lab Conditions 100 % increase in Paper tensile Index.
0
2040
6080
100120
140160
10% broken 30% broken
cont rol (unt reatedwhol e f i ber+unt reated brokenf i ber)Negat i ve whol ef i ber +posi t i vebroken f i ber
Effect of LbL Treatment of Mill Broke on Tensile index
70
75
80
85
90
1Pulp Compositions - see Legend
Tens
ile In
dex
- N m
/g
100% UB100% UM30% UB/70% UM30% TB/70% UM40% TB/60% UM
The Louisiana Tech Nano Pulp and Paper Initiative
Nanocoating of unwashed pulps in mill process waters “dirty water” increased tensile index by 15 %
50 % increase in tensile index allowsincreased fiber recycling
40
50
60
70
80
90
100
control (0%) 10% 20% 30% 40%
Broken Fiber ratio (%)
Tens
ile In
dex
(N•m
/g)
Control: Handsheets prepared from untreated w hole f ibersOthers: Handsheets prepared from LbL treated negative w hole fibers mixed w ith LbL treated positive broken fibers
Nanocoating paper mill broke (from Hodge LA) in clean lab conditions increased tensile index by 50% to 15%
St Louis, MO, June 25-27, 2008
Step 1.
Step 2.
Step 3.
Step 4.
St Louis, MO, June 25-27, 2008
Study on 100% OCC at USDA FS Study on 100% OCC at USDA FS FPL, Madison, WIFPL, Madison, WI
Used Recycled FiberUsed Recycled Fiber -- HydropulpingHydropulping of OCCof OCC
RefiningRefining after coating after coating –– Valley Beater Valley Beater
Partial (50%) CoatingPartial (50%) Coating
Washing Washing using filter paperusing filter paper
HandsheetHandsheet testing testing
Step 5.
St Louis, MO, June 25-27, 2008
600 620 640 660 680 700 72030
40
50
60
70
80Unrefined control, uncoated50% refined, uncaoted100% refined, uncoated
50% refined uncoated+50% unrefined coated, washed one layer three layers 50% refined uncoated+50% refined coated one layer, unwashed one layer, washed three layers, washed three layers, unwashed
Tens
ile in
dex
(Nm
/g)
Sheet density (kg/m3)
Sheet DensificationSheet DensificationStep 5.
Achieved higher tensile index with limited refining , which means less fines and mill residue
St Louis, MO, June 25-27, 2008
600 620 640 660 680 700 7202400
3000
3600
4200
4800
5400
Unrefined control, uncoated50% refined, uncaoted100% refined, uncoated
50% refined uncoated+50% unrefined coated, washed one layer three layers 50% refined uncoated+50% refined coated one layer, unwashed one layer, washed three layers, unwashed three layers, washed
Stiff
ness
inde
x (N
-m/g
)
Sheet density (kg/m3)
Sheet DensificationSheet DensificationStep 5.
Achieved higher stiffness with limited refining , which means less fines and mill residue
Broken fibers coated by washlessLbL-procedure (Fluorescent Confocal Laser Scanning Image (Leica). Only the fiber surfaces adsorbed the polyelectrolyte.
Amounts of polyelectrolytesneeded to achieve optimal (+) then (-) Zeta potentials for each consecutive layer were; 0.80mg PAH/g fiber, 1.0mg PSS/g fiber, 0.60mg PAH/g fibers, 1.20mg PSS/g fiber, & 0.60mg PAH/g fiber.
St Louis, MO, June 25-27, 2008
Development of “WashlessLbL Process” for pulp fibers
Step 6.
Cell wall microstructureChemical Composition Surface Morphology
Microfibril nanostructure
Pulping exposes the cellulose microfibrils, which are ~300 nm
in diameter, this creates a rough “nano-surface”
Cell wall nano-structure and chemical identity changes in the pulping process, so optimal polyelectrolyte loading has to be established for a given pulp and pulping process
Micro-, Ultra- and Nano- Structures of Cellulose Pulp Fibers
St Louis, MO, June 25-27, 2008
St Louis, MO, June 25-27, 2008
-20
-10
0
10
ζ-po
tent
ial,
mV
fiber
10 μ
l PA
H20
μl P
AH
30 μ
l PA
H40
μl P
AH
10 μ
l PS
S20
μl P
SS
30 μ
l PS
S40
μl P
SS
50 μ
l PS
S10
μl P
AH
20 μ
l PA
H30
μl P
AH
10 μ
l PS
S20
μl P
SS
30 μ
l PS
S40
μl P
SS
50 μ
l PS
S60
μl P
SS
10 μ
l PA
H20
μl P
AH
30 μ
l PA
H
Step 6.
Changes in ζ-potential with step-wise polyelectrolyte additions at 2.5 mg/mL/g of pulp increments. Pulp at pH 6.7. Five steps of PAH / PSS additions and subsequent depositions are shown with corresponding changes in surface potential in the outermost fiber surface. Experimental error is ±1 mV.
Electrolyte loadings for optimal Zeta potential for a given pulp
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-30
-20
-10
0
10
20
30
0 50 100 150 200
Time - min
Zeta
-pot
entia
l - m
v add PAH
add PAH again add PAH
add PSS
add PSS again
First LayerSecond Layer
Third Layer
Step 6.
Changes in ζ-potential in time after 2.5 ml/gm/g of pulp incremental polyelectrolyte additions. Five nanolayersor (PAH/PSS)2.5 double layer deposition are shown with corresponding surface potential changes on the outermost fiber surface. Experimental error is ±1 mV.
Effect of Pulp Buffering on the Optimal Zeta Potential and Total Necessary Electrolyte Loading
LbLLbL TechniqueTechnique
ConceptGeneration
RiskAssessment
Proof ofConcept
Proof ofProcess TransferDemonstration
ApproachDeploymentDecisions
ConceptGeneration
RiskAssessment
Proof ofConcept
Proof ofProcess Transfer
DemonstrationApproach
DeploymentDecisions
StageI
StageI
ConceptGeneration
StageI
StageI
ConceptGeneration
Stage2
Stage2
Risk Assessment &
Proof of Concept
Stage2
Stage2
Risk Assessment &
Stage3
Stage3
CompellingBusiness Case
Stage3
Stage3
CompellingBusiness Case
Stage4
Stage4
Proof ofProcess
Stage4
Stage4
Proof ofProcess
Stage5
Stage5
Large ScaleDemonstration &
Technology Transfer
Stage5
Stage5
Large ScaleDemonstration &
Technology Transfer
Gate1
Gate1
Gate2
Gate2
Gate3
Gate3
Gate4
Gate4
Gate5
Gate
5Industry support
Terminate ?Terminate ?
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SBIR Support
Next Step
5
Additional cooperators: University of West Hungary – use of stiff nanocoated fiber
University of Portugal - use of activated starch to reduce polyelectrolyte costs.
The LbL nanocoating technology to treat recycled fibers with the development of a “washless process” is ready for plant trials.Plant trials are planned in a small roofing-felt mill, using a mixture of positive LbL treated recycled fibers and negative untreated recycled pulps.
Future/Additional project work, develop low cost polyelectrolyte in cooperation with chemical suppliers
Current Status of the Louisiana Tech Nano Pulp and Paper Initiative
St Louis, MO, June 25-27, 2008
Industry Participants:Smurfit-Stone Corp., Hodge, LA
Thompson Equipment Co., New Orleans, LA
North American Pulp Molding, Haynesville, LA
THANK YOULouisiana Tech Nano Pulp and Paper
Initiative
in Cooperation with
USDA-FS-Forest Products Laboratory, Madison, WI
Nano Pulp and Paper, LLC, Ruston, LA
Niagara Falls, ON, Sept. 23-26, 2007