▎ 摘　　要

For the synthesis of polymer electrolyte membrane (PEM), high ionic conductivity and stability are the key challenge. This paper deals with the preparation of polymer electrolyte membranes based on ionic liquid (IL) functionalized graphene oxide (GO) and sulfonated polyether sulfone (SPES). Using a simple solution casting technique, composite membranes have been prepared possessing good physicochemical properties and mechanical stability. Methanol crossover resistance have been measured across the composite membranes and found to be low for IG-05 membrane (0.53 x10(-7) cm(2) s(-1)) with the selectivity of 7.99x 10(5). Composite IG-05 membrane also exhibit high ionic conductivity of 7.27x10(-2) S. cm(-1) which is around 66% higher than that of SPES membrane.