Two-Yukawa fluid at a hard wall: Field theory treatment

TL;DR

This paper develops a field-theoretical framework to analyze the structure and thermodynamics of a two-Yukawa fluid near a hard wall, incorporating mean field and fluctuation effects, and validating results against simulations.

Contribution

It introduces a comprehensive field-theoretical approach including Gaussian fluctuations for two-Yukawa fluids confined by a hard wall, extending beyond mean field approximations.

Findings

Derived mean field equations for density profiles.

Analytical expressions for free energy, pressure, and correlation functions.

Validated theoretical results with computer simulation data.

Abstract

We apply a field-theoretical approach to study the structure and thermodynamics of a two-Yukawa fluid confined by a hard wall. We derive mean field equations allowing for numerical evaluation of the density profile which is compared to analytical estimations. Beyond the mean field approximation, analytical expressions for the free energy, the pressure, and the correlation function are derived. Subsequently, contributions to the density profile and the adsorption coefficient due to Gaussian fluctuations are found. Both the mean field and the fluctuation terms of the density profile are shown to satisfy the contact theorem. We further use the contact theorem to improve the Gaussian approximation for the density profile based on a better approximation for the bulk pressure. The results obtained are compared to computer simulation data.