On RMSA description of liquid order in dilute charged colloidal suspensions

Abstract

The rescaled mean spherical approximation (RMSA) of Hansen and Hay-ter [1] is applied to a charged colloidal suspension having a liquid order. The effects of charge on the particle, particle concentration and impurity concentration on the structure factor, pair correlation function and the number of nearest neighbours are investigated in detail. The position of the first peak (Qm) in the structure factor depends strongly on particle concentration. The number of nearest neighbours in systems without any ionic impurity is close to that for the f.c.c. structure over a wide range of particle concentration. When ionic impurity is added to the suspension, the structure weakens, Qm shifts to higher values, the first peak in the pair correlation function shifts to lower values and the number of nearest neighbours continuously decreases. These effects are unique to the colloidal suspensions as compared with the molten metals. The physical origin of such a behaviour is discussed. The previously reported [2] disagreement between the estimated particle concentration from light scattering measurement and the actual one in liquid-like ordered suspension is explained. © 1986 Taylor & Francis Group, LLC.