Property Control of Layer-by-Layer Assembled Sulfonated Poly(phenylene oxide) Composite Membrane Based on Nafion for...

Multilayered composite proton exchange membranes were prepared by LbL method by alternating deposition of poly(diallyl dimethyl ammonium chloride) (PDDA) and highly sulfonated poly(phenylene oxide) (sPPO) onto the surface of Nafion 212. The sulfonated sPPO solution contained polystyrenesulfonic acid copolymer with azide moiety. Thickness of the LbL composite membrane was controlled by using the anionic solution of sPPO containing 0.5 M NaCl. The membranes were crosslinked by using UV to give the mechanical and chemical durability. The crosslinked composite membrane showed decreased methanol permeability with the increasing number of bilayers, and showed increased overall selectivity compared to Nafion film.