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 suspension of charged particles in front of a flat highly repulsive wall. The thermodynamic consistency condition used here is the matching of the force per unit area exerted by the macroparticles over the wall, with 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 computer simulation data. The main conclusion is that the Rogers-Young approximation is in closer agreement with the simulation data than the hypernetted chain and rescaled mean approximations presented in previous works. (C) 1996 American Institute of Physics.