Novel cross-linked poly(vinyl alcohol)-based electrolyte membranes for fuel cell applications

Herein, a new series of polymer electrolyte membranes was prepared by chemically cross-linked poly(vinyl alcohol) (PVA) and sulfonated poly(ether sulfone) (SPES). A typical polymerization reaction was conducted using three different monomers i.e. bisphenol A, phenolphthalein, and 4,4'-dichlorodiphenyl sulfone. The SPES polymer was obtained by the post-sulfonation technique using chlorosulfonic acid as a sulfonating agent. The resultant SPES polymer at different concentrations was blended with cross-linked poly(vinyl alcohol). Structural analysis of the samples was conducted by FTIR, SEM, and XRD. Among the prepared PEM materials, PVA-SPES-20 blend membranes exhibited higher ion-exchange capacity and % water uptake values than those of the other membranes. In addition, the PVA-SPES-20 membrane exhibits the proton conductivity of 0.0367 S cm^-1 at 30 °C, whereas pristine PVA shows the proton conductivity of 0.0259 S cm^-1. The overall experimental results revealed that the PVA-SPES blend membranes are promising candidates for fuel cell applications.