Irradiated PVdF-HFP–tin oxide composite membranes for the applications of direct methanol fuel cells

Poly(styrene sulfonic acid)-grafted poly(vinylidene fluoride-co-hexafluoroproplyene)/tin oxide composite membranes were prepared for the direct methanol fuel cells applications. The interconnected pores of the PVdF-HFP membranes endorsed the higher poly(styrene sulfonic acid) grafting. The incorporation of tin oxide particles decreased the polymeric content volume which was available for the grafting reaction and reduced the grafting degree values. The obtained morphological and structural characterizations confirmed the polystyrene grafting and sulfonic acid functionalization of the fabricated membranes. The incorporated tin oxide particles promoted the thermal stability of the composite membranes via its ceramic filler property. Though the composite membranes exhibited lower grafting values, the structural, bonded, and physisorbed water molecules of the tin oxide particles governed the prompt ionic conductivity values even at higher temperature and lower humidity conditions. The lower grafting and methanol resistive behavior of tin oxide particles distorted the fuel transportation channels and reduced the fuel permeability. By the combined efforts of high ions and lower molecular transportation, fuel cell efficiency was facilitated for the fabricated composite membranes and geared its potential applications in direct methanol fuel cells field.