Composite polymer electrolyte membranes from semi-interpenetrating networks of poly(vinyl alcohol) and silica nanoparticles containing poly(2-acrylamido-2-methyl-1-propanesulfonic acid)

Abstract

Polymer electrolyte membranes based on semi-interpenetrating networks of poly(vinyl alcohol) (PVA) and poly(acrylonitrile-co-styrene sulfonic acid) (PAN-co-PSSA) were reported. In the first part, the effect of PAN-co-PSSA content on membrane properties was investigated. Enhanced proton conductivity and oxidative stability were observed upon the introduction of PAN-co-PSSA. In the second part, silica nanoparticles containing poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS-Si) were synthesized via Stöber method, followed by radical polymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid on the silica particles. PAMPS-Si was characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM) linked with energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The effect of PAMPS-Si loading (0, 2.5, 5, 10, 15 and 20%) on membrane properties, including surface morphology, water vapor absorption, water uptake, ion exchange capacity, proton conductivity, and thermal, mechanical and oxidative stabilities, was investigated. The optimum PAMPS-Si loading was 15%. Composite membrane comprising 15% PAMPS-Si demonstrated a maximum proton conductivity of 0.0234 S/cm at 27 °C with relatively high oxidative stability.