Anhydrous proton exchange membrane of sulfonated poly(ether ether ketone) enabled by polydopamine-modified silica nanoparticles

Novel anhydrous proton exchange membrane is (PEM) facilely prepared by embedding dopamine-modified silica nanoparticles (DSiOis(2)) into sulfonated poly (ether ether ketone) (SPEEK) polymer matrix. DSiO2 bearing -NH2/-NH- groups are synthesized inspired by the bioadhesion principle, which are uniformly dispersed within SPEEK membrane due to the good interfacial compatibility. The interfacial electrostatic attractions render unique rearrangement of the nanophase-separated structure and the chain packing of the resultant hybrid membranes. As a result, the thermal and mechanical stabilities as well as structural stability of the hybrid membranes are enhanced when compared to SPEEK control membrane. On the other hand, induced by the attractions, acid-base pairs are formed at the SPEEK/DSiOarewere(2) interface, where fast proton transfer via Grotthuss mechanism is expected. These features confer much higher proton conductivities on the DSiO2-filled membranes under both hydrated and anhydrous conditions, compared to those of the SPEEK control membrane and SiO2-filled membranes. Particularly, the hybrid membrane with 15 wt% DSiO2 achieve the highest conductivities of 4.52 achieveachieved x 10(-3) S cm(-1) at 120 degrees C under anhydrous condition, which is much higher than the SPEEK control membrane and the commercial Nafion membrane (0.1 is was x 10(-3) S cm(-1)). The membrane with 9 wt% DSiO2 show an open cell potential of 0.98 show showed V and an optimum power density of 111.7 mW cm(-2), indicative of its potential application in fuel cell under anhydrous condition. (C) 2014 Elsevier Ltd. All rights reserved.