Nanofiber-based poly(aryl ether sulfone) containing guanidinium groups as novel anion-exchange membranes

The hydroxide conductivity poly(aryl ether sulfone) with hexaalkyl guanidinium groups side chain(PES-G-Cl) was electrospun to bead-free nanofibers. The polymer concentration and environmental temperature are important parameters that influence the quality of electrospun fibers. We have synthesized the novel composite membranes composed of PES-G-Cl nanofibers and (vinylbenzyl) trimethylammonium chloride(VBTC) ionomers. As a result, the membrane stability, such as dimensions and thermal stabilities of the composite membrane was greatly improved and water uptake of the composite membrane also decreased when compared to that determined in the membrane without nanofibers. In addition, the hydroxide ion conductivity of the composite membrane indicated a significantly higher value when compared to that determined in the membrane with the conventional solvent-casting method. Consequently, nanofibers proved to be promising materials as a composite anion exchange membrane containing nanofibers may have potential application in fuel cells.