FLUID-FLUID PHASE-SEPARATION IN BINARY-MIXTURES OF ASYMMETRIC NONADDITIVE HARD-SPHERES

The phase equilibria of symmetric and asymmetric non-additive hard-sph ere mixtures are studied via Monte Carlo simulation with the Gibbs ens emble technique. The phase diagram is also determined by a simple firs t-order perturbative theory (MIXI). The theory gives results for the c oexistence curve in reasonable agreement with the simulation. The asym metry of the curve increases and the position of the critical point sh ifts to higher concentration and lower density monotonically as functi on of the size ratio. The inadequacy of the usual integral equation ap proach for giving quantitative information about the location of the c ritical point is also confirmed.