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


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


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%


Step 1.

Step 2.

Step 3.

Step 4.


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.


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


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.


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



-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


-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 ?


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


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

washless multi-nano-layered fiber preparations · zeta-potential - mv add pah add pah again add pah...

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