Surface of silicate glass exposed to water

The surface and subsurface of commercial barium glassware were studied. The glass was exposed to water and annealing conditions. The decomposed oxygen peak shows the presence of hydrogen bonds to oxygen. Comparison of the amount of OH bonds obtained from oxygen peak decomposition with the amount obtained by the model on the basis of the charge balance shows a discrepancy, which is explained by the oversimplification of the model, which assumes the ideality of the glass structure. The results show that the silica subnetwork in the subsurface region is stable under the conditions used in the experiments. The amount of oxygen is kept constant during water leaching/annealing experiments, but oxygen can change among non-bridging oxygen, dangling/defect oxygen (DO) or H₂O/OH states according to the conditions under which the glass is exposed. Alkalis migrating into the alkali-depleted area during annealing prefer to replace hydrogen rather than bind to DO.