THEORETICAL-ANALYSIS OF THE COMPETITION BETWEEN COULOMBIC AND SPECIFIC INTERACTIONS AT CHARGED INTERFACES

We present a model of an inhomogeneous electrolyte solution based on t he Landau-Ginzburg approach. It contains coulombic interactions, ideal entropy contribution and non-local specific interactions. With this m odel we can study the specific interaction of the electrolyte with the electrode surface. Numerical calculations of the ionic density, poten tial and charge density profiles have been performed assuming reasonab le values of the phenomenological parameters. We also use numerical me thods to obtain differential capacitance as a function of charge densi ty and the magnitude of electrode/electrolyte specific interactions. I t is a new aspect of this approach that ions can be excluded from the immediate vicinity of the electrode surface. (C) 1998 Published by Els evier Science Ltd. All rights reserved.