An oxygen XAFS study of sodium disilicate glass surfaces

Abstract

Oxygen K-edge X-ray absorption fine structure (XAFS) spectroscopy has been employed to study the atomic structure near the surface of powdered and polished sodium disilicate glass. In the absence of lubricants, grinding in air produces substantial quantities of sodium carbonate. This is also present for surfaces polished in water but vanishes for surfaces polished in oil. Results are interpreted in terms of the modified random network (MRN) model in which microsegregated alkalis decorate newly created glass surfaces, reacting variously with oxygen, carbon dioxide and water.