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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
1
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
Presented by
1 - Introduction
5
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
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
ExamplesCellulosic 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
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
Amine and metal salt association Ionic interactions assisting dissolution
+< 20mol%
> 20mol%
SCNK+
ED
A
ED
A
EDA
ED
A
NH2CH2CH2NH2
EDA
ED
A
dissociation
association
EDA=
cell-OH
dissolutioncell-OH= cellulose
K+
ED
A
ED
A
EDA
ED
A
EDA
ED
A
SCN
ED
A
ED
A
EDA
ED
A
EDA
ED
A
10
Figure 3 – Coordination of ED and KSCN in solution9 Frey
Presented by
2 - Development of cellulose
blend membranes
11
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
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
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
Microscopic views of dissolution
15
Table 1 - Different swelling and dissolution mechanisms for cotton and wood fibers
in NMMO – water mixtures at various water contents.3
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.
34
Table 2 -Types of proteins used
35
Protein Optimum Percent
Brim Soy Protein (USDA) ~50
Profam 974 Isolate 40-50%
Presented by
3 - Cellulose and proteins
blended in solution to
make membranes
47
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
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
Presented by (click to enter name)
4 – Characterization of cellulose
/ soy protein blend membranes
50
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
TGA Analysis - cellulose membrane compared to cellulose/brim soy protein
blend
52
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
3030
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
100100
30 30
TGA Analysis - cellulose membrane compared to cellulose/Profam 974 soy protein blend
Table 3 - Summary of TGA results for soy protein / cellulose blend membranes
54
Table 8 - Comparison of TGA results between membranesMaterialsStart temperature
(ºC)
Onset temperature(s)
(ºC)
Char level @ 710º C
(%)
Cellulose fiber 242 350 11
Cellulose
membrane 257 332 28
Profam 974 189 276 27Brim soy
protein 193, 285 235, 310 25
Cellulose /
Profam 974
mixed185 290, 362 18
Cellulose /
Profam 974
membrane200 283 9
Cellulose /
brim mixed 201, 280 234, 355 19
Cellulose /
brim
membrane178 241 28
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
55
Figure 13 – Cellulose membrane Figure 14 – Cellulose / Profam 974
membrane
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
56
Figure 15 – Cellulose / Brim
blendFigure 16 – Cellulose / Profam
974 blend
NoticeNotice
Tensile Properties Summary
57
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
membrane157 ± 52 3.2 ± 1.6 27 ± 12 0.029 ± 0.003
Cellulose /
Profam 974
membrane200 ± 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
Physical Properties Summary
57
Table 5 – Comparison of water absorbency for soy blend membranes
Presented by
5 – Later work at
NCSU
59
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
Presented by
6 – Coming work at
Nazarbayev University
Brief Discussion
61
ConclusionsNew 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.
62
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.
63
Presented by
7 - References
64
1. Ott . Cellulose and cellulose derivatives : Molecular characterization and its application. Burlington:
Elsevier; 1954.
2. Khare VP, Greenberg AR, Kelley SS, Pilath H, Roh IJ, Tyber J. Synthesis and characterization of dense
and porous cellulose films. J Appl Polym Sci 2007;105(3):1228-36.
3. Cuissinat C, Navard P. Swelling and dissolution of cellulose part 1: Free floating cotton and wood fibres
in N-methylmorpholine-N-oxide-water mixtures. Macromolecular Symposia 2006;244(1):1.
4. Cuissinat C, Navard P. Swelling and dissolution of cellulose part II: Free floating cotton and wood fibres
in NaOH-water-additives systems. Macromolecular Symposia 2006;244(1):19.
5. Fink H, Weigel P, Purz HJ, Ganster J. Structure formation of regenerated cellulose materials from
NMMO-solutions. Progress in Polymer Science 2001 11;26(9):1473-524.
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Soc 2002;124(18):4974-5.
7. Zhang . 1-allyl-3-methylimidazolium chloride room temperature ionic liquid: A new and powerful non-
derivatizing solvent for cellulose. Macromolecules 2005;38(20):8272.
8. Hafez MM, Pauls HW, inventors. Method for preparing thin regenerated cellulose membranes of high flux
and selectivity for organic liquids separations. Exxon Research and Engineering Co., editor. 4496456.
1985 1/29/1985
9. Frey M, Li L, Xiao M, Gould T. Dissolution of cellulose in ethylene diamine/salt solvent systems.
Cellulose 2006 04/29;13(2):147-55.
10. Cao Y. Preparation and properties of microporous cellulose membranes from novel cellulose/aqueous
sodium hydroxide solutions. Journal of Applied Polymer Science [Internet]. [revised 2006;102(1):920.
11. Metzger J. Carbohydrate structures
http://chemistry.gcsu.edu/~metzker/Common/Structures/Carbohydrates/
12. Lee HJ. Novel cellulose solvent system and dry jet wet spinning of Cellulose/ED/KSCN solutions.
Raleigh, NC: North Carolina State University; 2007. Available from: unrestricted
65
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
66
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