Zeta-potential study of calcium silicate hydrates interacting with alkaline cations

An investigation into the interaction between alkaline cations and calcium silicate hydrates (CSH) was conducted by electrokinetic measurements, which provided information on the nature of the interface between the solid and its equilibrium solution. Calcium constitutes for the CSH surface a potenti al-determining cation. A model of the CSH surface could be proposed, accoun ting for the experimental evolution of the CSH zeta potential. The necessit y of studying the zeta-potential evolution of the system as a function of t he calcium activity, instead of its concentration, was underlined. The resu lts obtained suggest a specific interaction between cesium and the CSH surf ace, whereas sodium and lithium may behave as indifferent cations toward th e interface. (C) 2001 Academic Press.