Surface energies of solid electrodes

Anisotropic specific surface energies of solids changed in different ways after a change of state depending on the possibility of mass transport between the equilibrium surfaces. If mass transport is impossible, the solid is deformed by a nonhydrostatic stress field and the chemical potentials of the components become anisotropic. In order to establish full equilibrium with constant chemical potentials throughout the whole system, mass transport is necessary. Since it is slow for solids, there will be irreversible contributions to the specific surface energy. Changes of specific surface energy were measured as functions of electrode potential and electrolyte composition at solid electrodes by Koesters laser interferometry and compared to changes of mass and charge. In all cases investigated so far, electrocapillary curves of polycrystalline gold in aqueous solutions of potassium sulphate, potassium chloride, lead perchlorate, thallium perchlorate and zinc sulphate, and in partially miscible solutions in water and isobutyl alcohol of hydrochloric acid slowly changed with time. Copyright (C) 1996 Elsevier Science Ltd.