Novel Quaternized Poly(arylene ether sulfone)/Nano-ZrO2 Composite Anion Exchange Membranes for Alkaline Fuel Cells

A series of composite anion exchange membranes based on novel quaternized poly(arylene ether sulfone)/nanozirconia (QPAES/nano-ZrO2) composites are prepared using a solution casting method. The QPAES/nano-ZrO2 composite membranes are characterized by FTIR, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDX). The ion exchange capacity (IEC), water uptake, swelling ratio, hydroxide ion conductivity, mechanical properties, thermal stability, and chemical stability of the composite membranes are measured to evaluate their applicability in fuel cells. The introduction of nano-ZrO2 induces the crystallization of the matrix and enhances the IEC of the composite membranes. The modification with nano-ZrO2 improves water uptake, dimension stability, hydroxide ion conductivity, mechanical properties, and thermal and chemical stabilities of the composite membranes. The QPAES/nano-ZrO2 composite membranes show hydroxide ion conductivities over 25.7 mS cm(-1) at a temperature above 60 degrees C. Especially, the QPAES/nano-ZrO2 composite membranes with the nano-ZrO2 content above 7.5% display hydroxide ion conductivities over 41.4 mS cm(-1) at 80 degrees C. The Ea values of the QPAES/nano-ZrO2 composite membranes with the nano-ZrO2 content above 5% are lower than 11.05 kJ mol(-1). The QPAES/7.5% nano-ZrO2 composite membrane displays the lowest Ea value and the best comprehensive properties and constitutes a good potential candidate for alkaline fuel cells.