Preparation of ion-exchange membranes by the hydrolysis of radiation-grafted polyethylene-g-polyacrylamide films: Properties and metal-ion separation

摘要

Ion-exchange membranes were prepared by the alkaline hydrolysis of radiation-grafted polyethylene-g-polyacrylamide membranes. The hydrolyzed membranes showed a good water uptake of approximately 1060 for a graft level of 590%. The electrical resistance of the membranes decreased with an increase in the degree of grafting up to 200% and then stabilized with further increases in the graft level. The membranes had an excellent binding capacity for mercury ions. The metal-binding capacity increased with an increase in the degree of grafting in the membranes. A binding capacity as high as 7.2 mmol/g in a membrane with 590% grafting was achieved. The pH of the metal solution had a significant influence on the binding ability of the membranes. The partial hydrolysis of the grafted membranes contributed to the higher binding because of the expansion of the bulk structure by ionized carboxyl groups and the better accessibility of mercury to amide groups. The mercury-loaded membranes showed thermal stability inferior to that of membranes without metal binding. (C) 2003 Wiley Periodicals, Inc. [References: 32]