title: Dynamic swelling behavior of gamma-radiation induced polyelectrolyte poly(AAm-co-CA) hydrogels in urea solutions.
abstract: The aim of this study was to investigate the equilibrium swelling properties in urea solutions of gamma-radiation induced polyelectrolyte copolymeric hydrogels consisting of acrylamide (AAm) and crotonic acid (CA). Poly(acrylamide-co-crotonic acid), poly(AAm-co-CA) hydrogels containing different amounts of CA were obtained in the form of rods after radiation. Swelling experiments were performed in aqueous urea solutions at 25 degrees C, gravimetrically. The hydrogels showed large extents of swelling in aqueous (urea/water) media the swelling being highly dependent on the chemical composition of the hydrogels and irradiation dose. The percentage swelling of poly(AAm-co-CA) hydrogels was between 1160 and 4250%, while that of the AAm hydrogels was between 670 and 900%. The diffusional exponent values (n) are between 0.51 and 0.66, hence the diffusion of urea/water into the hydrogels is non-Fickian. Equilibrium urea/water contents of the hydrogel systems were changed between 0.870 and 0.977.
authors: Adnan Menderes University, Fen-Edebiyat Faculty, Department of Chemistry, 09010 Aydin, Turkey. ekaradag@adu.edu.tr
authors: Erdener
authors: E
authors: Karadağ
authors: Omer Bariş
authors: OB
authors: Uzüm
authors: Dursun
authors: D
authors: Saraydin
authors: Olgun
authors: O
authors: Güven
mesh_terms: D000178:Acrylamides / Q000737:chemistry* / Q000528:radiation effects; D000327:Adsorption; D003432:Cross-Linking Reagents; D003437:Crotonates / Q000737:chemistry* / Q000528:radiation effects; D004058:Diffusion; D005720:Gamma Rays; D020100:Hydrogels / Q000737:chemistry* / Q000528:radiation effects*; D007700:Kinetics; D012996:Solutions; D014508:Urea / Q000737:chemistry*
chemical_list: D000178:Acrylamides; D003432:Cross-Linking Reagents; D003437:Crotonates; D020100:Hydrogels; D012996:Solutions; C506718:poly(acrylamide-co-crotonic acid); D014508:Urea