Effect of Phase Separation on the Physical and Chemical Properties of Glasses-Density and Chemical Durability.

摘要

This report covers results from density and chemical durability measurements on a borosilicate glass widely used commercially for chemical glassware while the glass undergoes liquid-liquid immiscibility. A net decrease in density is observed during an isothermal heat-treatment below the transition temperature. This density or molar volume change is related to the effect of pressure on the phase transition temperature by means of equations derived herein. The chemical durability of the material is measured following the ASTM titration technique and shows a large degradation of chemical resistance to attack by water as a result of sub-immiscibility structure development. The effect is analyzed in terms of the change in composition of the phases associated with the immiscibility transition. (Author)