A PERTURBATIVE DENSITY-FUNCTIONAL APPROACH TO THE STRUCTURE OF COLLOIDAL SUSPENSION

A simple perturbative density functional approach which incorporates t he three-body correlation in an approximate manner is used to study th e structure of inhomogeneous as well as homogeneous colloidal suspensi on. The suspension is modeled as a one component fluid of charged macr o particles interacting with the well known Derjaguin-Landau-Verwey-Ov erbeek (DLVO) potential. We have calculated the density profiles of in homogeneous colloidal suspension in front of a highly repulsive charge d wall as well as in a planar slit consisting of two parallel planar c harged walls. The radial distribution function g(r) of the homogeneous suspensions of charged colloidal particles has also been calculated b y making use of the well known Percus identity which relates the densi ty distribution of an inhomogeneous fluid to the g(r) of the correspon ding homogeneous fluid when the external potential responsible for the inhomogeneity is the interparticle potential itself. The calculated r esults on the density profiles and g(r) obtained from the present appr oach are found to be in closer agreement with the simulation results a nd show a marked improvement over those obtained from perturbative as well as nonperturbative density functional theories presented in earli er works. (C) 1998 American Institute of Physics.