Colloidal suspensions in charged cylindrical pores: A perturbative densityfunctional approach

A simple theoretical scheme based on a perturbative density functional appr oach using an approximate three-particle correlation function in conjunctio n with a sum rule relating the bulk pressure with the free energy functiona l of an inhomogeneous system has been proposed to study the structure of a model colloidal suspension (with screened Coulomb interaction) confined in a charged cylindrical pore. The calculated density profiles for the confine d colloidal suspension for different values of the wall charges are shown t o compare well with the available computer simulation results. The importan ce of the third order term has been demonstrated through the significantly better agreement of the present results as compared to those based on secon d order perturbative approach. The relative contribution of the third order term, however, is shown to depend on the screening parameter and hence the salt concentration in the suspension. The effect of the diameters of the c ylindrical pores on the density profiles is also investigated. (C) 1999 Ame rican Institute of Physics. [S0021-9606(99)51426-8].