A density functional theory study of the confined soft ellipsoid fluid

TL;DR

This study uses classical Density Functional Theory to analyze confined soft ellipsoid fluids, comparing different free energy and correlation function models, and finds that numerical DCF aligns well with simulations.

Contribution

It evaluates the effectiveness of two different DCF models in DFT for confined soft ellipsoid fluids, providing insights into their accuracy in isotropic and nematic phases.

Findings

Numerical DCF yields good agreement with simulations for density and order profiles.

Parsons-Lee DCF performs well in isotropic but poorly in nematic phases.

Both models are useful but have phase-dependent accuracy.

Abstract

A system of soft ellipsoid molecules confined between two planar walls is studied using classical Density Functional Theory (DFT). Both the isotropic and nematic phases are considered. The excess free energy is evaluated using two different Ansaetze and the intermolecular interaction is incorporated using two different direct correlation functions (DCF). The first is a numerical DCF obtained from simulations of bulk soft ellipsoid fluids and the second is taken from Parsons-Lee theory. In both the isotropic and nematic phases the numerical DCF gives density and order parameter profiles in reasonable agreement with simulation. The Parsons-Lee DCF also gives reasonable agreement in the isotropic phase but poor agreement in the nematic phase.