Silica glasses with high surface area were prepared by the sol−gel method, the electrical conductivity of which was measured as a function of the content of adsorbed water. The glasses obtained by heating at 400−800 °C had specific surface areas of 700−900 m2/g glass and exhibited room-temperature conductivities of 10-6−10-3 S/cm by absorbing the water in pores. The activation energy for conduction linearly decreased with increasing logarithm of the product of proton and water concentration. On the other hand, the increase in conductivity was represented to be proportional to the logarithm of water concentration. Electrical conduction in glasses containing a large amount of water is related to the dissociation of protons from the SiOH bonds and the proton hopping through water molecules in pores.

Proton Conduction in Porous Silica Glasses with High Water Content

High proton conducting P2O5−SiO2 glasses were prepared using the sol−gel method, the electrical conductivities of which were studied in relation to the pore structure and the adsorbed water. The pore properties of SiO2 and P2O5−SiO2 glasses were controlled by addition of formamide during the gel synthesis, the specific surface areas of which were changed from 200 to 900 m2/g-glass. These glasses absorb water molecules on exposure to a humid atmosphere. The conductivity increased with increasing logarithm of water concentration and reached a saturated value above the water vapor pressure of 0.8. The highest conductivity, 2 × 10-2 S/cm at room temperature, was achieved by 5P2O5−95SiO2 glass heated at 700 °C and absorbing the water molecules.

High Proton Conductivity in Porous P2O5−SiO2 Glasses

Glasses can be engineered with a wide range of properties and in a variety of forms that make them important materials for current and emerging energy and environmental technologies. The increasing worldwide demand for sustainable, environmentally friendly energy supplies, and for access to clean water, will provide glass scientists and manufacturers opportunities to develop new materials for new markets. Glass applications for solar, wind and nuclear power generation are reviewed, and recent research on new glassy materials for super-capacitors and electrochemical devices is discussed, with an emphasis on the needs that will drive glass research through the year 2020.

A survey of energy and environmental applications of glass

High proton conductive glass electrolyte synthesized by an accelerated sol–gel process with water/vapor management

Presentation et commentaire des resultats obtenus au cours de differentes etudes realisees sur ce sujet

Determination of combined water in glasses by infrared spectroscopy

Simple relations between protonic conductivity ($\ensuremath{\sigma}$) and the peak wave number (${\ensuremath{\nu}}_{\mathrm{OH}}$) of O-H infrared absorption band, and between activation energy for the electrical conduction and the wave number (${\ensuremath{\nu}}_{\mathrm{OH}}$) were found in oxide glasses containing no alkali- and/or transition-metal ions. The present investigation enables one to evaluate the protonic conductivity and the activation energy at a unit proton concentration of a given glass specimen from an ir spectrum of the glass plate, respectively.

Yoshio Ohta

Papers

Protonic conduction in oxide glasses: Simple relations between electrical conductivity, activation energy, and the O-H bonding state.