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Synthesized Hydrogels (synthesized + hydrogel)
Selected AbstractsIrradiation synthesis of biopolymer-based superabsorbent hydrogel: Optimization using the Taguchi method and investigation of its swelling behaviorADVANCES IN POLYMER TECHNOLOGY, Issue 2 2009Ghasem R. Bardajee Abstract In this report, the synthesis of a novel superabsorbent hydrogel via ,-irradiation graft copolymerization of acrylamide onto sodium alginate and kappa-carrageenan hybrid backbones in a homogeneous solution is described. The Taguchi method was used as a powerful experimental design tool for synthesis optimization. A series of superabsorbent hydrogels was synthesized by proposed conditions of Qualitek-4 software. Considering the results of nine trials according to analysis of variance, optimum conditions were proposed. The swelling behavior of optimum superabsorbent hydrogels was studied in various solutions, with pH values ranging from 1 to 13. In addition, swelling kinetics, swelling in various organic solvents, the absorbency under load, and on,off switching behavior were investigated. Also, hydrogel formation was confirmed by Fourier transform infrared spectroscopy. Surface morphology of the synthesized hydrogels was assessed by scanning electron microscopy. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 28:131,140, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20154 [source] Swelling properties of CMC- g -poly (AAm- co -AMPS) superabsorbent hydrogelJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2009Ali Pourjavadi Abstract A series of biopolymer-based superabsorbent hydrogels based on carboxymethyl cellulose has been prepared by free-radical graft copolymerization of acrylamide and 2-acrylamido-2-methylpropan sulfonic acid (AMPS) in aqueous solution using methylenebisacrylamide as a crosslinking agent and ammonium persulfate as an initiator. The effect of variables on the swelling capacity such as: acrylamide/AMPS weight ratio, reaction temperature, and concentration of the initiator and crosslinker were systematically optimized. The results indicated that with increasing the amount of AMPS, the swelling capacity is increased. FT-IR spectroscopy and scanning electron microscope analysis were used to confirm the hydrogel structure. Swelling measurements of the synthesized hydrogels in different salt solutions indicated considerable swelling capacity. The absorbency under load of the superabsorbent hydrogels was determined by using an absorbency under load tester at various applied pressures. A preliminary swelling and deswelling behaviors of the hydrogels were also studied. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Partially hydrolyzed kappa carrageenan,polyacrylonitrile as a novel biopolymer-based superabsorbent hydrogel: Synthesis, characterization, and swelling behaviorsPOLYMER ENGINEERING & SCIENCE, Issue 12 2006M. T. Savoji In this paper, synthesis and swelling behavior of a novel superabsorbent hydrogel based on kappa carrageenan (,C) and polyacrylonitrile (PAN) was investigated. To achieve partially hydrolyzed ,C-PAN hydrogel, physical mixture of ,C and PAN was hydrolyzed by NaOH solution. During alkaline hydrolysis, the nitrile groups of PAN are converted to a mixture of hydrophilic carboxamide and carboxylate groups follow by in situ crosslinking of the grafted PAN chains. The reaction variables affecting on the swelling capacity of the hydrogel were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. Under the optimized conditions concluded, super swelling hydrogel with the ability of water absorption up to 3260 g/g (water/dry hydrogel powder) has been prepared. Swelling measurements of the synthesized hydrogels was carried out in various salt solutions and solutions with different pH. The results indicate that the hydrogels have good pH sensitivity and pH-reversible property between pH 2 and pH 8. POLYM. ENG. SCI. 46:1778,1786, 2006. © 2006 Society of Plastics Engineers. [source] Biocatalytic hydrogels by template polymerizationPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 5 2008H. El-Sherif Abstract Novel ionizable hydrogels were prepared from poly(acrylic acid) and dimethylaminoethyl methacrylate monomer employing template polymerization technique as an alternative to traditional physical and chemical crosslinking. The mode of interaction, as proved by Fourier Transform Infrared Spectroscopy (FTIR), was multiple H-bonding between the tertiary amino group of the monomer and the carboxylic groups of the polymer. The hydrogels represented suitable matrices for enzyme immobilization. The effect of varying the polymer,monomer molar ratio on the swelling kinetics and parameters was investigated. The dynamic swelling isotherm exhibited a Fickian mode of penetrant sorption and a plateau that increases with the amino group content. A polymer complex of molar ratio (polymer:monomer) 0.5:0.8 had a weight swelling ratio of 10 and 7 at pHs 3 and 8, respectively. The proven pH sensitivity together with the amphoteric character of these hydrogels make them good candidates for another bioapplication such as oral delivery systems of therapeutic peptides and proteins. The structural integrity of the hydrogels was proved by their swelling reversibility. , -Galactosidase, as an acidic model enzyme, was immobilized covalently on the synthesized hydrogels. The maximum enzyme velocity (Vmax) was enhanced to 19,µmol/min/mg, for polycomplex of molar ratio 0.5:0.8, compared with 3.2,µmol/min/mg for the free enzyme. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||