Preparation of hybrids derived from zinc phosphate glasses and benzimidazole for anhydrous proton conduction applications

Anhydrous proton-conducting hybrid materials have been prepared using zinc metaphosphate glass and benzimidazole. In the present work, the glasses containing hydrated crystals, as the starting material, were used for preparing the hybrids to examine the influence of the hybrid structure on their electrical conductivities. The glass powders were exposed to humidified conditions and subsequently heated at 150 °C to form crystal phases in the glasses; the treated powders included large amounts of ortho- and pyrophosphate groups. Proton-conducting hybrids were successfully prepared by programmed-heating the mixtures consisting of the treated powders and benzimidazole to 220 °C. The resulting hybrids were amorphous and thermally stable up to 200 °C. One of the hybrids prepared using the treated powders containing large amounts of hydrated crystals showed higher conductivities than that prepared using the mother glass. The humidifying-heating process of the metaphosphate glass powders, prior to hybridization with benzimidazole, plays an important role in an increase in orthophosphate groups in the resulting hybrids, leading to improvement of their electrical conductivities.