The preparation and the application of grafted polytetrafluoroethylene fiber as a cation exchanger for adsorption of heavy metals

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 3.06 mmol/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.