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Abstract: Thermo- and pH-sensitive hydrogels were prepared by graft copolymerization of chitosan (CS) and N-isopropylacrylamide via γ-radiation. The effects of monomer concentration and irradiation dose on grafting percentage and grafting efficiency were studied. The graft copolymers were characterized by 13C CP/MAS NMR and thermogravimetric analysis. The pH and thermosensitivity and swelling properties of the hydrogels were investigated. The results showed that the grafting percentage and grafting efficiency increased with the increase of monomer concentration and total irradiation dose. The highest grafting percentage is 620%, the lower critical solution temperature (LCST) of this hydrogel is about 28°C. [Copyright &y& Elsevier]

Abstract: A novel type of weakly acidic cation exchange fiber have been prepared by 60Co irradiation grafting with acrylic acid onto the polytetrafluoroethylene (PTFE) fiber. The exchange capacity of the grafted fiber is 3.06mmol/g. The pH titration curve of the grafted fiber showed there is a sudden jump when pH is round 6–10, and the acidity of the grafted fiber is stronger than that of commercial weakly acidic exchange D-152 resin. The grafted fiber showed the excellent selectivity of static and dynamic adsorption for Cu2+, La3+ and Pb2+ when Mg2+, Ca2+, Cr3+, Co2+, Ni3+, Cu2+, Ag+, La3+, Pb2+ were coexisted. The grafted fiber could be regenerated completely with almost equimolar diluted hydrochloric acid. [Copyright &y& Elsevier]