Contributions of Repulsive and Attractive Interactions to Nematic Order

TL;DR

This paper develops a unified theory combining repulsive and attractive molecular interactions to explain nematic order, emphasizing high-density behavior and the transition to Maier-Saupe thermotropic nematics.

Contribution

It introduces a novel unified theoretical framework for nematic order that accounts for both repulsive and attractive interactions, focusing on high-density effects.

Findings

High-density nematic order exhibits a unique compact support in configuration space.

Attractive interactions induce a transition to Maier-Saupe thermotropic behavior.

A critical attractive interaction strength marks the onset of thermotropic nematic phase.

Abstract

Both repulsive and attractive molecular interactions can be used to explain the onset of nematic order. The object of this paper is to combine these two nematogenic molecular interactions in a unified theory. This attempt is not unprecedented; what is perhaps new is the focus on the understanding of nematics in the high density limit. There, the orientational probability distribution is shown to exhibit a unique feature: it has compact support on configuration space. As attractive interactions are turned on, the behavior changes, and at a critical attractive interaction strength, thermotropic behavior of the Maier-Saupe type is attained.