Synthesis of organic/inorganic hybrid composite membranes and their structural and conductivity properties

The present article describes the use of a less expensive non-perfluorinated polymer (polyvinyl alcohol, PVA), heteropolyacid (HPA), glutaraldehyde and 3-aminopropyltriethoxysilane (APTES) for the formation of high proton-conducting hybrid composite membranes. The conductivity of the PVA/PMA/Gl/APTES hybrid composite membranes was measured under varying conditions of temperature (from − 20 °C to 140 °C) and relative humidity (from 30 to 90%). Conductivity values in the range of 10− 3–10− 1 S cm− 1 were obtained for the hybrid membranes. These free-standing flexible films were mechanically stable and the corresponding composite membranes were thermally stable up to 300 °C. Their swelling ratio was calculated for dry and wet conditions at room temperature.