PNNL

Abstract

Although glass corrosion resistance has been tested using laboratory methods for decades, investigators are now just beginning to understand the reaction phenomena at or close to saturation with respect to the rate-limiting phase(s). Near saturation, the phenomena that govern element release rates are unique to the vitreous state and include alkali-hydrogen (species) exchange, phase separation, and precipitation of secondary minerals. This review discusses the two over-arching models for glass reactivity, diffusion and surface reaction control, and demonstrates the importance of glass reactivity in terms of glass composition and micro-heterogeneity of the glass. Our conclusion is that surface reaction control best describes the release of elements to solution, but that models based on transition state theory (TST) must be modified to account for reported anomalies in behavior near saturation.