Radiation-Grafted Polymer Electrolyte Membranes for Fuel Cells

Fuel cells are one of the most efficient energy conversion systems to produce electricity. A solid ion-conducting polymer membrane is employed as both separator and electrolyte for polymer electrolyte membrane fuel cells and anion-exchange membrane fuel cells. Radiation-induced graft polymerization is a versatile method for the fabrication of low-cost alternatives to commercial polymer membranes. In this method, typically a base polymer is exposed to ionizing radiation which generates active radical sites within the polymer substrate. Then a suitable vinyl monomer is polimerized on these active sites to form a graft copolymer. Finally, a subsequent chemical treatment is performed to introduce hydrophilic groups to hydrophobic polymer backbone so that an ion conducting membrane is formed. There are various studies about the influence of radiation grafting parameters on membrane properties. Moreover, the favorable fuel cell relevant and polarization properties of such radiation-grafted membranes were reported. Thus, radiation-grafted polymer membranes are one of the significant low-cost alternatives for fuel cells. This review focuses on the preparation, characterization of fuel cell relevant properties and fuel cell performance of radiation-grafted membranes.