Concentrated colloidal dispersions viewed as one-component macrofluids

Abstract

The problem of obtaining a quantitative statistical-mechanical description of the structure of concentrated colloidal dispersions is greatly simplified if the only significant correlations are those between the colloidal particles themselves. The medium in which the particles are dispersed may then be treated as a uniform background, which has the physical characteristics necessary to ensure electroneutrality and appropriate dielectric properties, but is otherwise featureless. The problem thus reduces to calculating correlations within a single-component fluid of finite particles having a specified pairwise interaction. This paper will discuss the use of current liquid-state theories to calculate the static structure of such one-component macro-fluids, and will consider some of the experimental evidence which confirms the validity of the approach. In particular, examples will be taken from light- and neutron-scattering experiments on concentrated dispersions of neutral, charged or magnetic particles of approximately spherical shape, and the extension to other systems will be briefly considered.