A thermotropic nematic of slightly non-spherical molecules: generalized van der Waals theory

Abstract

A simple generalization is given of the Maier—Saupe model of thermotropic liquid crystals to the case of slightly non-spherical particles. This allows the inclusion of multipolar forces at the mean-field level. Additionally, it is shown that increasing the (small) molecular elongation may actually destabilize the nematic phase. Within the present scheme, the roles of (short range) overlap and (long range) dispersion forces in determining phase behaviour can be assessed separately.