Depletion potential in hard sphere fluids

TL;DR

This paper introduces a new, versatile method for calculating depletion potentials in multicomponent hard sphere fluids applicable at various densities, validated through density functional theory and simulations.

Contribution

It presents a novel approach that works for any number of components and densities, with two routes for zero-density limits, compatible with DFT and simulations.

Findings

Density functional results match simulations closely.

Method applicable to any component number and density.

Accurate calculation of depletion potential near a planar wall.

Abstract

A versatile new approach for calculating the depletion potential in a hard sphere mixture is presented. This is valid for any number of components and for arbitrary densities. We describe two different routes to the depletion potential for the limit in which the density of one component goes to zero. Both routes can be implemented within density functional theory and simulation. We illustrate the approach by calculating the depletion potential for a big hard sphere in a fluid of small spheres near a planar hard wall. The density functional results are in excellent agreement with simulations.