Improvement of Proton-ExchangeMembranes Based on(1x)(H3PO2/PVA)-xTiO2

Abstract

Using impedance spectroscopy (IS), differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), and infrared spectroscopy (IR) tech-niques to study the polymer electrolyte membranes based on poly(vinylalcohol) (PVA) and hypophosphorous acid (H3PO2) with different tita-nium oxide nanoparticles (TiO2) concentrations. The polymer systems(1−x)(H3PO2/ PVA) +xTiO2were prepared using the sol-casting methodand different weight percent of TiO2,x≤10.0œ. The DSC results showthat the glass transition for molar fraction P/OH = 0.3 appears around 75°Cand for the samples doped with TiO2around 35°C; the melting pointfor all membranes appear around 175°C. The FTIR spectra show changesin the profiles of the absorption bands with the addition of H3PO2andthe different concentrations of TiO2. The IS results show dielectric andconductivity relaxations as well as a change in DC ionic conductivity withthe TiO2content. The order of the ionic conductivity is about10−2S/cmfor 5.0œof TiO2. The TGA in the heating run shows water loss that is inagreement with DC conductivity measurements.