Radiolytic preparation and characterization of poly(styrene sulfonic acid)-grafted ETFE membranes

In this study, ETFE-g-PSSA membranes with various degrees of grafting (DOG) and thicknesses were prepared by a simultaneous irradiation method. SEM-EDX instrument was applied to measure the relative distribution of sulfur which is corresponding to that of a grafted polymer over the crosssection of the ETFE-g-PSSA membranes prepared at various irradiation conditions. The results indicate that to obtain the evenly-grafted membranes, a styrene/dichloromethane ratio is needed to be under 60 (v/v%), and a higher DOG is required as the film thickness increases. The effects of DOG and thickness on the ion exchanging capacity (IEC) and water uptake (WU) were investigated by measuring the IEC and WU values of the membranes with various DOG and thicknesses.