Functionalized membranes were obtained by radiation-induced graft copolymerization (RIGP) of acrylamide-acrylic acid (AAm-AAc) and acrylamide-4-vinyl pyridine (AAm-4VP) binary monomers on both low-density polyethylene and polypropylene films. The supporting conditions as inhibitor concentration, irradiation dose comonomer compositions and concentrations were studied and optimized. The prepared membranes were characterized using SEM, DTA-TG, and FTIR. They proved that supporting the selected hydrogels on the base films have modified their structure and enhanced their thermal and mechanical characteristics. The sorption characteristics of Th(IV) and U(VI) on the different membranes were studied. The amount of ions sorbed at equilibrium was found to increase with increase in the degree of graft at certain conditions. The kinetics of sorption was also studied and found to obey the Lagergren and Morris-Weber kinetic models. (c) 2006 Wiley Periodicals, Inc.