SGO/SPES-based highly conducting polymer electrolyte membranes for fuel cell application.

Proton-exchange membranes (PEMs) consisting of sulfonated poly(ether sulfone) (SPES) with enhanced electrochemical properties have been successfully prepared by incorporating different amount of sulfonated graphene oxide (SGO). Composite membranes are tested for proton conductivity (30-90 °C) and methanol crossover resistance to expose their potential for direct methanol fuel cell (DMFC) application. Incorporation of SGO considerably increases the ion-exchange capacity (IEC), water retention and proton conductivity and reduces the methanol permeability. Membranes have been characterized by FTIR, XRD, DSC, SEM, TEM, and AFM techniques. Intermolecular interactions between the components in composite membranes are established by FTIR. The distribution of SGO throughout the membrane matrix has been examined using SEM and TEM and found to be uniform. The maximum proton conductivity has been found in 5% SGO composite with higher methanol crossover resistance.