2000/05/22 by R. Roth, Roland Roth, R. Evans +2 · 17 citations
Earth and Planetary Sciences · Engineering · Materials Science · Physics and Astronomy · #High-pressure geophysics and materials #Material Dynamics and Properties #Phase Equilibria and Thermodynamics #cond-mat.soft
paper · pdf · doi:10.1103/physreve.62.5360
arxiv created 2000/05/22 · openalex publication_date 2000/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We present a versatile density functional approach (DFT) for calculating the depletion potential in general fluid mixtures. In contrast to brute force DFT, our approach requires only the equilibrium density profile of the small particles \em before the big (test) particle is inserted. For a big particle near a planar wall or a cylinder or another fixed big particle the relevant density profiles are functions of a single variable, which avoids the numerical complications inherent in brute force DFT. We implement our approach for additive hard-sphere mixtures. By investigating the depletion potential for high size asymmetries we assess the regime of validity of the well-known Derjaguin approximation for hard-sphere mixtures and argue that this fails. We provide an accurate parametrization of the depletion potential in hard-sphere fluids which should be useful for effective Hamiltonian studies of phase behavior and colloid structure.