Depletion potential in the infinite dilution limit

TL;DR

This paper calculates depletion forces and potentials between large hard spheres in a mixture of small spheres using the Rational Function Approximation, showing improved accuracy over Percus-Yevick theory and aligning well with simulations.

Contribution

It applies the Rational Function Approximation to compute depletion interactions in multicomponent hard-sphere mixtures, extending previous methods.

Findings

Improved accuracy over Percus-Yevick theory.

Good agreement with simulation results.

Explicit analysis of equal and unequal big particles cases.

Abstract

The depletion force and depletion potential between two in principle unequal "big" hard spheres embedded in a multicomponent mixture of "small" hard spheres are computed using the Rational Function Approximation method for the structural properties of hard-sphere mixtures [S. B. Yuste, A. Santos, and M. L\'opez de Haro, J. Chem. Phys. {\bf 108}, 3683 (1998)]. The cases of equal solute particles and of one big particle and a hard planar wall in a background monodisperse hard-sphere fluid are explicitly analyzed. An improvement over the performance of the Percus-Yevick theory and good agreement with available simulation results are found