This document presents research on developing compatible cellulose and cellulose blended membranes using a novel solvent system. The objectives are to review previous work, develop cellulose blend membranes, and characterize the new membranes. Cellulose was blended with soy protein in solution and cast to make non-porous blend membranes. The blend membranes were characterized through SEM, TGA, XRD, and tensile testing. The soy protein blend membranes showed improved strength and water absorbency over pure cellulose membranes. Future work includes making blend fibers and cross-linking membranes to prevent degradation in water. The solvent system allows functional blend membranes to be produced from cellulose and other biopolymers like starch, chitosan and proteins.

1. Presented by (click to enter name)
Development and characterization of compatible cellulose
and cellulose blended with soy protein membranes using a
novel solvent system
By
Eugene F. Douglass, MS, PhD
Department of Chemistry
Nazarbayev University, Astana, Kazakhstan
&
Richard Kotek, PhD
TECS, College of Textiles
North Carolina State University, Raleigh, NC USA
June 28, 2010
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2. Objectives -
 Reviewing briefly the literature, and previous work with
this system. To summarize the recent work developing
new fibers and membranes using our novel solvent
system.
 To show the development of biopolymer blend cellulose
membranes, using previous work as a foundation.
 To show the characterization of the membranes.
 To extend the preliminary goals of the research into a
new creative area, developing brand new materials that
may have use in the membrane industry, and to
characterize these new materials.
2

3. Presented by
1 - Introduction
5

4.  Layer of material which serves as a selective barrier
 Barrier is between two or more phases
 Remains impermeable to specific particles, molecules or
substances
 Osmotic forces enable free flow of solvents
 Some components are allowed passage into permeate stream
 Others are retained and remain in the retentate stream
6

5. Cellulosic sources
 Cellulose most abundant naturally occurring polymeric
raw material – very cheap raw material
 Wood pulp, cotton, other plant fibers, or plant waste
Figure 1- Molecular structure of cellulose.11
7

6. Examples
Cellulosic fibers and membranes
 Natural cellulose fibers: cotton, linen, & flax
 Regenerated cellulose: rayon fiber and film, cellophane film
 Cellulose dissolved in a solvent: Lyocell fiber and film
 Cellulose derivatives: nitrocellulose, celluloid, cellulose acetate fibers and films
Early solution methods – Regenerated cellulose: Cellulose xanthate is made, dissolved,
then regenerate the cellulose chemically.
 Viscose process
 Rayon
 Problems: dangerous solvent, toxicity of waste material
Recent solution methods – Dissolve cellulose in a solvent system
 Lyocell process – prime commercial process
 Lyocell
 Problems: solvent instability issues, expensive
8

7. Amine and counter ion dissolution
Zn+2 > Li+ > Ca+2 > Mg+2 > Ba+2 > Na+ > NH4
+ > K+
SCN- > I- > PO4
-3 > Br- > Cl- > NO3
- > SO4
-2 > ClO3
-
Order of decreasing swelling of cellulose 2
9
Figure 2 – Swollen cellulose –
crystal structure
A) ac sin γ projection;
B) ab projection 2

8. Amine and metal salt association
 Ionic interactions assisting dissolution
+< 20mol%
> 20mol%
SCNK
+
EDA
EDA
EDA
EDA
NH2CH2CH2NH2
EDA
EDA
dissociation
association
EDA=
cell-OH
dissolution
cell-OH= cellulose
K
+
EDA
EDA
EDA
EDA
EDA
EDA
SCN
EDA
EDA
EDA
EDA
EDA
EDA
10
Figure 3 – Coordination of ED and KSCN in solution9 Frey

9. Presented by
2 - Development of cellulose
blend membranes
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10. Previous work at North Carolina State University
Hyun Lee12 – developed cellulose fibers from this optimized solvent blend,
and did some basic membrane investigation
 Possible porous membrane
 Severe yellowing upon aging
 Problems:
 could not reproduce this structure using means described
 Used non-reproducible method of casting
 Used tape layers on glass rods
 Draw down on glass plate, hard to remove
12
Figure 4 – Porous cellulose
membrane12

11. Development of new casting process for reproducibility
 Reproducibility is required
 Casting table
 Uniform casting bar
 Cast on PET plastic film for ease of placing in coagulation bath
and removal of coagulated membranes
 Obtained casting table and bars from Byk-Gardner
 Obtained casting PET film and drawdown panels for
sample membranes
13

12. Objective: Dissolution of cellulose and starch or protein as a
blend50)
 Simple setup for
dissolution, paddle
stirrer apparatus
14
Figure 5 - 7% free flowing ED/KSCN
cellulose (DP = 450) solution
Figure 6 – Dissolution apparatus

13. Microscopic views of dissolution
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Table 1 - Different swelling and dissolution mechanisms for cotton and wood fibers
in NMMO – water mixtures at various water contents.3

14. Background of invention of new
material
 Cellulose and starch are polysaccharides
 Bond linkage of glucose units different
 Solvent for cellulose works, perhaps would work for starch.
 Discussion with Drs. Kotek, Venditti, and Pawlak: Can starch make
a membrane with this solvent system? No, could we do a blend??
Motivation
 Attempt blend with starch for membranes; success!
 Based on success with starch; chitosan, chitin and soy protein were
also tried.
 Both porous and nonporous membranes were obtained, this section
describes the development of cellulose blended with soy protein to
form a useful membrane.
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15. Table 2 -Types of proteins used
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Protein Optimum Percent
Brim Soy Protein (USDA) ~50
Profam 974 Isolate 40-50%

16. Presented by
3 - Cellulose and proteins
blended in solution to
make membranes
47

17. Development of cellulose / soy protein blend
membranes
 Based on success with Starches, we thought protein might work
 First attempt with Brim Soy Protein isolate, received from USDA labs on NCSU
campus
 Two protein types in the Brim blend
 Dissolves well in solvent blend
 ADM soy materials received from NC Soy Council
 SAF soy protein
 Archon F soy protein concentrate
 Profam 974 soy protein isolate (comparable to Brim)
48

18.  Sample blend membranes made from each
protein, to determine best quality membranes.
 Brim and Profam 974 made best quality
membranes
 These were used for main characterization
 Determine ideal mass ratios of Soy protein to
cellulose using Profam 974 at 40, 30 and 20%
by characterization of each mass percent
membrane.
49

19. Presented by (click to enter name)
4 – Characterization of cellulose
/ soy protein blend membranes
50

20. SEM cross section micrographs of 50/50 cellulose –
soy protein blends – Compatible!
51
Figure 7 – 50/50 Cellulose/brim
membrane, 5000x
Figure 8 – 50/50 Cellulose/Profam
974
membrane, 5000x

21. TGA Analysis - cellulose membrane compared to cellulose/brim soy protein
blend
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Figure 9 - Cellulose membrane:
Onset 332º C, end 371º C, ash
about 28% Figure 10 - Cellulose / brim blend
membrane: Onset 241º C, end
342º C, ash about 28%
Mass %
20o C
20o C
710o C
710o C
100 100
30
30

22. 53
Figure 11 - Cellulose membrane:
Onset 332º C, end 371º C, ash
level about 28%
Figure 12 - Cellulose / Profam
974 blend membrane: Onset
284º C, end 344º C, ash level
about 9%
Mass %
20o C
20o C 710o C
710o C
100
100
30 30
TGA Analysis - cellulose membrane compared to cellulose/Profam 974 soy protein blend

23. Table 3 - Summary of TGA results for soy protein / cellulose blend membranes
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Table 8 - Comparison of TGA results between membranesMaterials
Start temperature
(ºC)
Onset temperature(s)
(ºC)
Char level @ 710º C
(%)
Cellulose fiber 242 350 11
Cellulose
membrane 257 332 28
Profam 974 189 276 27
Brim soy
protein 193, 285 235, 310 25
Cellulose /
Profam 974
mixed
185 290, 362 18
Cellulose /
Profam 974
membrane
200 283 9
Cellulose /
brim mixed 201, 280 234, 355 19
Cellulose /
brim
membrane
178 241 28

24. Wide Angle X-ray Scattering of Profam 974 blend membrane
Cellulose II Structure Amorphous Structure
Peaks at 16,17 and 23 2θ Broad Peak at 20-22 2θ
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Figure 13 – Cellulose membrane Figure 14 – Cellulose / Profam 974
membrane

25. Wide Angle X-ray Scattering of Stretched Soy Protein blend membranes
Amorphous Structure Amorphous Structure
Peaks at around 14 and 21 2θ Around 14 and 21 2θ
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Figure 15 – Cellulose / Brim
blend
Figure 16 – Cellulose / Profam
974 blend
Notice
Notice

26. Tensile Properties Summary
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Table 4 – Comparison of Tensile properties for soy blend membranes
Samples Tensile modulus
(kgf/mm2)
Failure stress
(kgf/mm2)
Failure strain
(%)
Thickness
(mm)
Cellulose
membrane 75 ± 12 2.5 ± 1.2 36 ± 12 0.047 ± 0.015
Cellulose /
brim
membrane
157 ± 52 3.2 ± 1.6 27 ± 12 0.029 ± 0.003
Cellulose /
Profam 974
membrane
200 ± 75 4.7 ± 1.2 16 ± 8.0 0.026 ± 0.001
Cell / PF
40% 220 ± 53 5.0 ± 2.0 29 ± 12 0.026 ± 0.001
Cell / PF
30% 204 ± 74 4.3 ± 2.3 27 ± 12 0.031 ± 0.005
Cell / PF
20% 195 ± 69 2.4 ± 1.8 20 ± 12 0.034 ± 0.003

27. Physical Properties Summary
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Table 5 – Comparison of water absorbency for soy blend membranes

28. Presented by
5 – Later work at
NCSU
59

29. Presented by (click to enter name)
• Made blend fibers from
cellulose / waxy maize, and
cellulose / soy protein blends.
• Cross-linked cellulose and
cellulose blend membranes to
prevent falling apart in long
term water contact.
60

30. Presented by
6 – Coming work at
Nazarbayev University
Brief Discussion
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31. Conclusions
New dissolution process development:
 Using a special solvent system of ED/KSCN in a 65/35
mass % ratio, functional porous and non-porous
membranes were produced that have comparable
physical properties to other methods of making cellulose
membranes.
New material development:
 Using the same solvent system, soy protein was blended
with cellulose in the solution and cast to make functional
non-porous blend membranes, that are stronger than the
cellulose porous membranes developed earlier, and very
water absorbent.
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32. Conclusions
 Using the same solvent system, soy protein was blended
with cellulose to make functional non-porous blend
membranes, that are strong and even more water
absorbent than the blend membrane with starch.
 The casting and drying processes were optimized to deal
with issues of shrinkage that causes wrinkling and
variable film thicknesses
 Other polysaccharides (chitosan and chitin), and protein
(keratin from hair) were also used to make functional
blend membranes with cellulose, suggesting further
applications for this system, perhaps using wool will give
some interesting materials, both as membranes and
fibers.
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33. Presented by
7 - References
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1985 1/29/1985
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11. Metzger J. Carbohydrate structures
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Raleigh, NC: North Carolina State University; 2007. Available from: unrestricted
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35. 8- Acknowledgements
 North Carolina State University, College of Textiles
including
 Drs. Richard Kotek, Peter Hauser and Alan Tonelli
 Dr. Richard Venditti and Dr. Joel Pawlak, College of Natural
Resources
 Chuck Mooney, Birgit Anderson and Theresa White
 Nazarbayev University, Astana, Kazakhstan seed
funding to disseminate this work, and develop further
work
 Drs. Kenneth Alibek SST, Sergey Mikhalovsky College of
Engineering
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