ROGERS-YOUNG APPROXIMATION FOR THE CONCENTRATION PROFILE OF A COLLOIDAL SUSPENSION IN FRONT OF A HIGHLY REPULSIVE WALL

In this work we present an extension of the Rogers-Young approximation to the determination of the concentration profile of a colloidal susp ension of charged particles in front of a flat highly repulsive wall. The thermodynamic consistency condition used here is the matching of t he force per unit area exerted by the macroparticles over the wall, wi th the corresponding osmotic pressure in the bulk determined from the virial equation. The suspension is described as a one-component fluid, constituted by the macroparticles, with all the relevant interactions modeled by the Derjaguin-Landau-Verwey-Overbeek effective potentials. The predictions of this new scheme are compared with Monte Carlo comp uter simulation data. The main conclusion is that the Rogers-Young app roximation is in closer agreement with the simulation data than the hy pernetted chain and rescaled mean approximations presented in previous works. (C) 1996 American Institute of Physics.