Simulation and theory of the electrochemical double layer for strong ionic interactions

Abstract

Abstract In order to obtain agreement with experiment, the Gouy-Chapman (GC) theory of the electrochemical interface must be parametrized empirically. Surprisingly, this difficulty does not seem to have detracted from the popularity of the GC theory. However, the use of empirical parameters precludes a definitive experimental test of the GC theory. Very recently, computer simulations have been employed to examine the electrochemical interface. If the ionic coupling is not to strong (large ions, low valence, large dielectric constant, high temperature), the GC theory, although lacking, is qualitatively satisfactory. However, for strongly coupled ions the GC theory fails completely. Regrettably, so do the ‘better’ theories. Recently, a theory that is partially satisfactory has been developed. Our simulations, this theory, and what is needed for a more satisfactory theory is discussed.