On the Equivalent Conductivity of Silicate Anions

The equivalent conductivities of the two main silicate species, [[EQUATION]] and [[EQUATION]], are indispensable parameters to study many physico-chemical phenomenons of silicate materials in electrolyte solutions (e.g., diffusion, adsorption, or phase transformations). However, literature data exhibits inconsistency and has received only limited scholarly attention. In this paper, a conductivity model for mixed electrolytes is established and verified. With this model the equivalent conductivities of the two silicate species were measured with electrochemical impedance spectroscopy (EIS) in the temperature range of 4.7 to 35.3 °C. The accuracy of the results is fully discussed via multiple perspectives. This work lays the foundation for quantitative investigation of phase transformation of silicate materials with potentiometric method.