New hydrogel containing sulfur compound prepared by gamma irradiation and its application for metal recovery

A new hydrogel that contains sulfur is prepared by radiation polymerization and its application for recovery of Hg2+, Pb2+, Cd2+, and Cu2+ ions is dis cussed. The metal hydrogel complexes are isolated and characterized by usin g different spectroscopic techniques (UV-visible, IR, NMR, and mass), therm al analysis (TGA and DSC) measurements, and SEM. Also, the mode of complexa tion is determined using IR and NMR spectroscopy. The scanning electron mic rographs show that the hydrogel has a great ability to recover the metal io ns in the following order: Hg2+ > Cd2+ > Pb2+ > Cu2+. TGA thermograms are u sed to investigate the mechanism of thermal decomposition. (C) 2000 John Wi ley & Sons, Inc.