ELECTROSTATIC ADSORPTION OF COLLOIDAL PARTICLES ON THE WALLS OF A PLANAR SLIT - SIMULATION VERSUS THEORY

A simple theoretical scheme is employed to calculate the equilibrium local concentration profile of a model suspension of highly charged colloidal particles inside a planar slit in the regime corresponding to attractive and weakly repulsive wall-particle interactions. In addition, we report the results of Monte Carlo simulations for the same system and conditions. As expected from previous theoretical work involving a single confining wall, we find that in this regime, theory and simulations predict the existence of an electrostatically adsorbed monolayer of colloidal particles on each of the two confining walls of the slit, and that this is independent of the wall-to-wall separation. Furthermore, we find that this monolayer "renormalizes" the charge of the corresponding wall, thus producing the same structure of the nonadsorbed particles, as that produced by highly repulsive walls. This idea is shown to be quantitatively accurate according to both, the simulation and the theoretical results.