DEPLETION EFFECTS IN BINARY HARD-SPHERE FLUIDS

We report a molecular dynamics computation of the entropic depletion f orce induced between two large spheres (colloidal particles) immersed in a fluid of small spheres. The effective pair potential obtained by numerical integration of the force is used in a Monte Carlo study of t he phase behaviour of the binary mixture. The simulation results are c ompared with the relevant theoretical predictions that follow from var ious integral equations for liquid mixtures. The simulations provide e vidence for a spinodal instability in a liquid mixture of hard spheres with a size ratio of 0.1.