Electrostatic Adsorption of Uniformly Charged Sphere Ions Confined between Two Charged Plates

Abstract

The theoretical model, which is based both on the modified fundamental-measure theory for the hard-sphere contribution and on the mean-field approximation for the cross correlation between the hard sphere contribution and Coulomb interaction, has been developed for studying the electrostatic adsorption of uniformly charged sphere ions. The Poisson equation by ions carrying charges that are spatially separated has been solved. The present theory shows an excellent agreement with the simulation data even for the large hard-sphere ions and is better than the modified Poisson- Boltzmann model. The calculated result shows that (i) the local particle and charge densities are strongly related to the charge distribution of ions, and that (ii) at large and strongly surfaceassociated ion the cross correlation between the hard sphere contribution and Coulomb interaction as well as the hard-sphere contribution becomes important, whereas the hard sphere contribution of charged ions relatively dominants at the weakly surface-associated ion.