On the molecular theory of dimer liquid crystals

TL;DR

This paper develops a statistical mechanics model to describe the nematic phase of dimer liquid crystals, accounting for spacer-mediated correlations, and successfully reproduces experimental thermodynamic and dielectric properties.

Contribution

It introduces a new approximation scheme for modeling configurational correlations in dimer liquid crystals, enhancing understanding of their phase behavior.

Findings

Transition temperatures vary with spacer length.

Order parameters match experimental trends.

Dipolar correlations are accurately predicted.

Abstract

We present a statistical mechanics approximation scheme for the explicit treatment of spacer-mediated configurational correlations among the mesogenic units that form a dimer molecule. The approximation is applied to the description of the nematic phase of linear uniaxial dimers interacting via a standard molecular pair-potential. Transition temperatures, order parameters and pair correlation averages are calculated for different spacer lengths. The results readily reproduce the experimentally observed trends of phase transition thermodynamics and of dipolar correlations deduced from dielectric studies.