Smectic-A Free Standing Film of Lennard-Jones Spherocylinder Model

TL;DR

This paper introduces a Lennard-Jones spherocylinder model for smectic-A liquid crystals capable of forming free-standing films, and investigates their phase behavior and film tension through Gibbs ensemble and Monte Carlo simulations.

Contribution

It presents a new molecular model for smectic-A liquid crystals and demonstrates the formation and properties of free-standing films using simulation techniques.

Findings

Coexistence of isotropic, nematic, and Sm-A phases with vapor identified.

Sm-A free-standing film can be produced below the bulk transition temperature.

Film tension depends on temperature and number of molecules.

Abstract

A spherocylinder-like molecule with a Lennard-Jones type interaction is proposed as a model of smectic-A (Sm-A) liquid crystals, which can form a free-standing film. By means of Gibbs ensemble simulations, the isotropic, nematic, and Sm-A phases of the model fluid are found to coexist with a vapor phase; and the coexistence conditions of the liquid crystal phases with the vapor phase are determined. For a set of the interaction-parameters of the model molecule, the Sm-A free-standing film is produced below the bulk isotropic--Sm-A phase transition temperature by using Monte Carlo simulations. The film tension of the Sm-A free-standing film is calculated and its dependencies on the temperature and on the number of molecules are discussed.