Study on functionally gradient proton exchange membrane fabricated by EB irradiation with heterogeneous energy deposition

The revolutionary functionally gradient proton exchange membranes were fabricated by EB irradiation with heterogeneous energy deposition. These heterogeneous energy deposition profiles (Depth-Dose profiles) were simulated by Monte Carlo simulation code EGS5. In the process of EB-grafting method of styrene onto base fluorinated polymer, the energy depositions selected from the Depth-Dose profiles were used. The grafted membranes were sulfonated with chlorosulfonic acid in carbon tetrachloride. The DOGs in the direction of thickness showed that EB Depth-Dose profiles corresponded to the EB grafting reaction. The functionally gradient proton exchange membranes had a water uptake gradient in the direction of depth, and hence could be a promising solution to manage water behavior in Membrane Electrode Assembly (MEA) of Polymer Electrolyte Fuel Cell (PEFC).