Solubility of gases in vitreous silica described by a distribution of dissolution energies

Abstract

The solubility of gases in vitreous silica complies well with Henry's Law at low pressures. Deviations observed at high pressures have been explained by site saturation, i.e., the number of dissolved molecules approaches the number of available sites that are assumed to have all the same energy of solution. In the present study, the observed deviations from Henry's Law are explained by a gradual saturation of sites of increasing energy. Experimental data of the solubility of hydrogen, helium, and neon in vitreous silica can be described by a Gaussian distribution of dissolution energies and Fermi-Dirac statistics. The solubility of hydrogen in metallic glasses, as well as the solubility of small molecules in glassy polymers, has been interpreted, and now, glasses in vitreous silica fit into this general concept of small particles in amorphous matrices.