Preparation of poly(vinyl alcohol) hydrogels containing citric or succinic acid using gamma radiation

Ternary mixtures of poly(vinyl alcohol) (PVA)/citric acid (CA)/water and PVA/succinic acid (SA)/water were exposed to various gamma doses in air at ambient temperature. The maximum swelling and the gelation% of the prepared gels initially increases with increasing dose for both acids, but at higher doses decreases. The uptake of nickel and cobalt ions increases with increasing bonded acid concentration, which can be explained with increase of the reactive acidic sites bonded to the polymer backbone. The uptake of copper ions is very limited, but it increases with increasing irradiation dose. (C) 2005 Elsevier Ltd. All rights reserved.