End‐group cross‐linked membranes based on highly sulfonated poly(arylene ether sulfone) with vinyl functionalized graphene oxide as a cross‐linker and a filler for proton exchange membrane fuel cell application

Abstract

AbstractHigh‐performance end‐group cross‐linked sulfonated poly(arylene ether sulfone) (SPAES) membranes are developed using thiolate‐terminated SPAES with very high degree of sulfonation (DS) such as 90 mol% (SK‐SPAES90) and vinyl functionalized graphene oxide (VGO) as a cross‐linker and a filler through the thiol‐Michael addition reaction. Since free‐standing membranes for fuel cell application could not be prepared using the water soluble and highly proton conductive SPAES with high DS of 90 mol%, cross‐linked SPAES90 membranes are intentionally prepared. The cross‐linked membranes are found to have good physicochemical properties with excellent proton conductivity that can be applied for the proton exchange membrane. In particular, the cross‐linked SPAES90 membrane prepared using 1.0 wt% of VGO exhibits better dimensional stability than a SPAES70 membrane from the linear SPAES with DS of 70 mol% and the proton conductivities of this membrane are larger than those of Nafion 211 at 80 °C under different relative humidity conditions (40%‐95%).