Formation of a surface layer of multicomponent lead-silicate glasses in hydrogen on heating

Abstract

X-ray electron spectroscopy and thermodynamic analysis are used to investigate the sequence of chemical transformations of the elements of a surface layer of silicate glass in the system PbO - BaO - Na 2 O - Al 2 O 3 - SiO 2 under heating in a hydrogen atmosphere. The process of thermal reduction of a multicomponent lead-silicate glass in hydrogen is a multistage process of diffusion and chemical interaction of lead with hydrogen. Reduction of lead is observed, the lead atoms bound with aluminum-oxygen groupings interacting being the first to interact with hydrogen after which the lead atoms in the silicon-oxygen structural units interact with hydrogen. The remaining components of the glass do not interact with hydrogen in the temperature range 375-475°C. The concentration profiles of the elemental distribution in the surface layer of the reduced glasses are determined.