Organic/inorganic composite membranes comprising of sulfonated Poly(arylene ether sulfone) and core–shell silica particles having acidic and basic polymer shells

Sulfonated poly(arylene ether sulfone) (SPAES) based composite membranes were prepared with core–shell silica particles having poly(4-styrenesulfonic acid) and poly(4-vinylpyridine) in shell layers named S–Si and P–Si, respectively, to investigate the effect of acidic and basic silica fillers on membrane properties. The core–shell silica particles were obtained by hydrolysis of vinyltrimethoxysilane followed by radical polymerization of vinyl monomers (4-styrenesulfonic acid sodium salt and 4-vinylpyridine) on the silica particle with vinyl groups. Incorporation of S–Si and P–Si into SPAES increased dimensional stability, mechanical strength, and proton conductivity of the membranes. In particular, P–Si was found to be more effective filler materials to improve these properties by additional well-connected hydrophilic channels having sulfonate/pyridinium structures formed around the silica particles through the acid–base interaction between the pyridine groups of the P4VP shell and the sulfonic acid groups of SPAES.