Monte Carlo Simulation of a Binary Mixture of Hard Rods and Hard Spheres

Abstract

One simple model molecule to examine phase behavior of rod-like molecules is the hard spherocylinder. 1) It is a simple cylinder of diameter d and length l with caps of hemispheres of the same diameter on both ends of the cylinder. Computer simulations have revealed that the system of monodisperse parallel hard spherocylinders shows the nematic and the smectic-A phase as liquid crystalline phases. 2), 3) Computer simulation and mean field theory have also studied a binary mixture of the parallel hard spherocylinders and hard spheres. 4) They have shown that the smectic-A phase of the binary mixture appears as a type of microphase separation. The spheres prefer to stay in the interstitial regions between smectic layers of the spherocylinders. In the present paper, we show an estimation of the Gibbs free energy obtained from isobaric Monte Carlo (MC) simulation for the binary mixture.