The dependence of the electrode properties of glasses on their composition. The second approximation: Taking into account ion mobilities in the surface layers

Abstract

AbstractThe electrode properties of glasses reflect the structural role of their components: network‐former or network‐modifier. The main evidence of this is the shape of the potential — pH curves and the potentiometric selectivity coefficient, KpotHM of the known Nicolsky equation. KpotHM is a product of two factors: the “energy factor” (the equilibrium constant of an exchange reaction of H+ and M+ ions between glass and solution, KexchHM) and the “dynamic factor” (ion mobility ratio in a glass surface layer, UM/UH).In the 1960s and for some time thereafter the energy factor was mainly used to explain the dependence of electrode properties of glasses on their composition (“the first approximation”). In this paper we consider the cases of the predominant effect of the dynamic factor on the electrode behavior of the glasses xLi2O‐xAl2O3‐0.25‐xB2O3‐(100‐2.25x) SiO2 and mixed‐alkali glasses 24% (Me′2O+Me''2O)‐12% Al2O3‐64% SiO2.