Physical and electrochemical properties of PVA/TiO2 nanocomposite membrane

A casting method becomes used for the preparation of the polyvinyl alcohol (PVA)/TiO2 nanocomposite. Characterization of the casting membranes was done using Fourier transform infrared spectrometer (FTIR), thermal gravimetric analysis, and AC impedance method. Surface morphology, element analysis, and distributions were investigated by scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX). Positron annihilation spectroscopy was used to examine the microstructure of the membranes under study, while their crystallinity was checked by wide-angle X-ray diffraction (WAXD). The FTIR spectra suggest a strong interaction between TiO2 and PVA nanoparticles, whereas WAXD results indicated that the amalgamation of TiO2 nanoparticles into the PVA matrix lowers the main crystallinity of PVA. The free volume size for PVA/TiO2 with cross-linker decreases suggest that the filling of the cavities by Ti3+ and O- ions as well as complex formation, that is, lead to a lower value of permeability. Because of their lower cost, higher thermal and lower permeability, the cross-linked PVA/TiO2 membrane was considered to use in alkaline direct methanol fuel cells.