On the Structure of Hard-Sphere Suspensions in a Discrete Solvent

Suspensions of spherical particles in a liquid are modelled by a binary mixture of small and large spheres, with diameters ?1 and ?2, which accounts for the discrete nature of the solvent. It is shown within the Percus-Yevick approximation that in the limit ?1/?2???0, the pair distribution function of the large spheres does not go over to that of a one-component fluid at the same density, but exhibits a ?-peak at contact (r?=??2) due to an expelled solvent effect.