Fabrication and characterization of graphene/sulfonated polyether sulfone octyl sulfonamide hybrid film with improved proton conductivity performance

In this study, graphene (G) was blended with sulfonated polyether sulfone octyl sulfonamide (SPESOS) in different ratios (1, 1.5, and 2 wt.%) to enhance the proton conductivity of SPESOS. The results of the water absorption analysis and current impedance spectroscopy of a G/SPESOS hybrid film showed that the proton conductivity improved due to the hydrophilic-hydrophobic nature of the hybrid. Further analysis showed that the synthesized hybrid film had a desirable contact angle and good ion exchange capacity, water absorption, and thermal stability. The hybrid film with 2 wt.% graphene showed better proton conductivity (92 mS/cm) than the pristine SPESOS film (34 mS/cm) at 100% relative humidity. These results suggested that the synthesized hybrid films offered superior proton conductivity, ion exchange capacity, and hydrophilicity compared to pristine SPESOS.