Perturbation Theory for Nematic Liquid Crystals of Axially Symmetric Molecules: Extension of Calculations to High Pressures

Abstract

We have applied a statistical mechanical perturbation theory to study the thermodynamic properties of nematic liquid crystals under pressure. In this theory the reference potential function is nonspherical and consists of the short range rapidly varying repulsive part of the pair potential. We report calculations on the nematic-isotropic (NI) transition properties for a hard spherocylindrical system superposed with an attractive potential, which is a function of only the centre of mass distance and the relative orientation between the two molecules, and subjected to different external pressures. The interaction arising from dispersion interaction between two asymmetric molecules represents the attractive interaction. The influence of pressure on the stability, ordering and thermodynamic functions for the NI transition is analysed. It is found that the theoretical predictions are in accordance with the experimental observations.