Synthesis and Properties of Chitosan-Graft Polyacrylamide/Gelatin Superabsorbent Composites for Wastewater Purification

Superabsorbent polymers received much attention and are used in many fields because of their superior characters to traditional absorbents, e.g., sponge and cotton. So, it is very important but challenging to prepare highly and fast-swelling superabsorbents. A reliable, efficient and low-cost technique for removing heavy metal ions from wastewater is the adsorption using bio-adsorbents obtained from biological materials, such as polysaccharides-based hydrogels superabsorbents. In this study, novel multi-functional superabsorbent composites type semi-interpenetrating polymer networks (Semi-IPNs) were prepared via graft polymerization of acrylamide onto chitosan backbone in presence of gelatin, CTS-g-PAAm/Ge, using potassium persulfate and N,N’-methylene bisacrylamide as initiator and crosslinker, respectively. These hydrogels were also partially hydrolyzed to achieve superabsorbents with ampholytic properties and uppermost swelling capacity. The formation of the grafted network was evidenced by Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Thermogravimetric Analysis (TGA). The porous structures were observed by Scanning Electron Microscope (SEM). From TGA analysis, it was concluded that the incorporation of the Ge in the CTS-g-PAAm network has marginally affected its thermal stability. The effect of gelatin content on the swelling capacities of these superabsorbent composites was examined in various media (distilled water, saline and pH-solutions). The water absorbency was enhanced by adding Ge in the network, where the optimum value was reached at 2 wt. % of Ge. Their hydrolysis has not only greatly optimized their absorption capacity but also improved the swelling kinetic.These materials have also showed reswelling ability. We believe that these super-absorbing materials would be very effective for the adsorption of harmful metal ions from wastewater.

Authors:

• H. Ferfera-Harrar
• N. Aiouaz
• N. Dairi

Keywords:

• Chitosan
• gelatin
• superabsorbent
• water absorbency.

References:

[1] M.J.Zohuriaan-MehrKabiriK. Superabsorbent Polymer Materials: A
Review. Iran Polym J (2008) 17:451-477.
[2] Buchholz F.L. Recent advances in super absorbent polyacrylates. Trends
PolymSci (1994) 2:277-281.
[3] Kim J.Y., Kim T.H., Kim D.Y., Park N.G., Ahn K.D. Novel thixotropic
gel electrolytes based on dicationicbis-imidazolium salts for quasi-solidstate
dye-sensitized solar cells. J Power Sources, (2008) 175:692-697.
[4] Yang L., Yang Y., Chen Z., GuoC., Li S. Influence of super absorbent
polymer on soil water retention, seed germination and plant survivals for
rocky slopes eco-engineering, Ecological Eng (2014) 62:27–32.
[5] Zohuriaan-Mehr M.J., OmidianH., DoroudianiS., KabiriK. Advances in
non-hygienic applications of superabsorbent hydrogel materials, J Mater
Sci (2010) 45:5711–5735.
[6] KabiriK., OmidianH., Zohuriaan-Mehr M.J., DoroudianiS.
Superabsorbent Hydrogel Composites and Nanocomposites: A Review,
Polym. Composite (2011) 32:277-289.
[7] TangH., ChenH., DuanB., LuA., ZhangL. Swelling behaviors of
superabsorbent chitin/carboxymethylcellulose hydrogels, J Mater Sci
(2014) 49:2235–2242.
[8] ZhouY., FuS., ZhangL., ZhanH. Superabsorbent nanocomposite
hydrogels made of carboxylated cellulose nanofibrils and CMC-g-p(AAco-
AM), CarbohydPolym (2013) 97:429–435.
[9] Dragan E.S. Design and applications of interpenetrating polymer
network hydrogels: A review, ChemEng J (2014) 243:572–590.
[10] Wang L., Zhang J., Wang A. Fast removal of methylene blue from
aqueous solution by adsorption onto chitosan-g-poly (acrylic
acid)/attapulgite composite. Desalination (2011) 266:33–39.
[11] ZhangG., YiL., DengH., Sun P. Dyes adsorption using a synthetic
carboxymethylcellulose-acrylic acid adsorbent. J. Environ Sci (2014) 26:
1203–1211.
[12] Chang C.Y., Duan B., CaiJ., Zhang L.N. Superabsorbent hydrogels
based on cellulose for smart swelling and controllable delivery.
EurPolym J (2010) 46:92-100.
[13] Lanthong P., Nuisin R., Kiatkamjornwong S. Graft copolymerization,
characterization, and degradation of cassava starch-gacrylamide/
itaconic acid superabsorbents. Carbohydrate Polym (2006)
66:229-45.
[14] Pourjavadi A., Jahromi P.E., Seidi F., Salimi H. Synthesis and swelling
behavior of acrylated starch-g-poly (acrylic acid) and acrylated starch-gpoly(
acrylamide) hydrogels. Carbohydrate Polym (2010) 79:933-40.
[15] Mellegard H., Strand S.P., Christensen B.E., Granum P.E., Hardy S.P.
Antibacterial activity of chemically defined chitosans: Influence of
molecular weight, degree of acetylation and test organism. International
J Food Microbiol (2011) 148:48-54.
[16] Muzzarelli R.A.A. Nanochitins and nanochitosans, paving the way to
eco-friendly and energy-saving exploitation of marine resources.
PolymSci: A Comprehensive Reference (2012) 10:153–164.
[17] Ferfera-HarrarH., AiouazN., Dairi N., Hadj-Hamou A.S. Preparation of
chitosan-g-poly(acrylamide)/montmorillonite superabsorbent polymer
composites: Studies on swelling, thermal, and antibacterial properties. J
ApplPolymSci (2014) 131:39747.
[18] Shankar P., Gomathi T., Vijayalakshmi K., Sudha P.N. Comparative
studies on the removal of heavy metals ions onto crosslinked chitosan-gacrylonitrile
copolymer, Inter J Bio Macromolecules (2014) 67:180–188.
[19] Maity J., Ray S.K. Enhanced adsorption of methyl violet and congo red
by using semi and full IPN of polymethacrylic acid and chitosan,
Carbohydrate Polym(2014) 104:8–16.
[20] Ferfera-Harrar H., Dairi N. Elaboration of cellulose acetate
nanobiocomposites using acidified gelatin-montmorillonite as nanofiller:
Morphology, properties, and biodegradation studies. Polym Composite
(2013) 34:1515–1524.
[21] Ferfera-Harrar H., Dairi N. Green nanocomposite films based on
cellulose acetate and biopolymer‑modified nanoclays: studies on
morphology and properties. Iran Polym J (2014) 23:917-931.
[22] KumirskaJ., CzerwickaM., KaczyńskiZ., BychowskaA.,BrzozowskiK.,
ThömingJ., StepnowskiP. Application of spectroscopic methods for
structural analysis of chitin and chitosan. Mar Drugs (2010) 8:1567-
1636.
[23] Silverstein R.M., Bassler G.C, Morrill T.C. Spectrometric identification
of organic compounds. (1991) John Wiley & Sons, New York.
[24] Pourjavadi A., AyyariM., Amini-Fazl, M.S. Taguchi optimized synthesis
of collagen-g-poly(acrylic acid)/kaolin composite superabsorbent
hydrogel. EurPolym J (2008) 44:1209- 1216.
[25] BaoY., MaJ., Li N. Synthesis and swelling behaviors of sodium
carboxymethylcellulose-g-poly(AA-co-AM-co-AMPS)/MMT
superabsorbent hydrogel. Carbohydrate Polym(2011) 84:76-82.
[26] Zhao Q., Sun J., Lin Y., Zhou Q. Superabsorbency, Study of the
properties of hydrolyzed polyacrylamide hydrogels with various pore
structures and rapid pH-sensitivities. Reactive FunctPolym (2010)
70:602-609.
[27] PourjavadiA., Mahdavinia G.R. Superabsorbency, pH-Sensitivity and
Swelling Kinetics of Partially Hydrolyzed Chitosan-g-poly (Acrylamide)
Hydrogels. Turkish JChem(2006) 30: 595-608.
[28] Zhou C., Wu Q. Novel polyacrylamide nanocomposite hydrogel
reinforced with natural chitosan nanofibers. Colloid Surf B (2011)
84:155-162.
[29] Martucci J.F., Vázquez A., Ruseckaite R.A. Nanocomposites based on
gelatin and montmorillonite morphological and thermal studies. J Therm
Anal Calorim(2007) 89:117-122.
[30] Wang W., Wang A. Synthesis and swelling properties of pH-sensitive
semi-IPN superabsorbent hydrogels based on sodium alginate-gpoly(
sodium acrylate) and polyvinylpyrrolidone. Carbohydrate Polym
(2010) 80:1028–1036.
[31] Chang C., Chen S., Zhang L. Novel hydrogels prepared via direct
dissolution of chitin at low temperature: structure and biocompatibility. J
Mater Chem (2011) 21:3865.
[32] Tang H., Chen H., Duan B., Lu A., Zhang L. Swelling behaviors of
superabsorbent chitin/carboxymethylcellulose hydrogels. J. Mater Sci
(2014) 49:2235–2242.
[33] Zhao Y., Kang J., Tan T. Salt-, pH- and temperature-responsive semiinterpenetrating
polymer network hydrogel based on poly(aspartic acid)
and poly(acrylic acid). Polymer (2006) 47:7702.
[34] Çaykara T., Doĝmus M., Kantoĝlu Ö. Network Structure and Swelling–
Shrinking Behaviors of pH-Sensitive Poly(acrylamide-co-itaconic acid)
Hydrogels. J PolymSci: Part B: PolymPhys (2004) 42:2586–2594.
[35] Bardajee G.R.,Pourjavadi A., Soleyman R. Novel highly swelling
nanoporous hydrogel based on polysaccharide/protein hybrid backbone.
J Polym Res (2011) 18:337–346.
[36] El-SayedM., Sorour M., Abd-El-Moneem N., Talaat H., Shalaan H., El-
MarsafyN. Synthesis and properties of natural polymers-graftedacrylamide.
World ApplSci J (2011) 13:360-368.
[37] Mahdavinia G.R., Pourjavadi A., Hosseinzadeh H., Zohuriaan M.J.
Modified chitosan 4. Superabsorbent hydrogels from poly(acrylic acidco-
acrylamide) grafted chitosan with salt- and pH-responsiveness
properties.EurPolymJ(2004) 40:1399-1407.