Polymer grafted GO/sulfonated copolyimide proton exchange nanocomposite membrane: as a polymer electrolyte membranes fuel cell

Attaining a high performance proton exchange membrane as a suitable replacement for Nafion is one of the research priorities of fuel cell research. In this regard, we synthesized a copolyimide consisting of sulfonic acid substituents filled with different content of GO grafted sulfonated poly (urea-co-urethane) via in situ condensation polymerization. All nanocomposites showed a significant increase in thermal, mechanical properties, ion exchange capacity (IEC), water uptake (WU) and proton conductivity by incorporation of the modified GO nanosheets and the best results were found for membrane containing 1 wt% modified GO loading. The nanocomposite membrane with 1 wt% modified GO nanosheets exhibits 0.73 meq g−1 IEC and 7.3 mS cm−1 proton conductivity at room temperature. A single fuel cell test of this membrane demonstrates a maximum power density of 26.30 mW cm−2 at 0.26 V.