2007/05/31 by Alexandr Malijevský, Alexandr Malijevsky, S. B. Yuste +3 · 1 citation
Chemical Engineering · Engineering · Materials Science · Physics and Astronomy · #Material Dynamics and Properties #Phase Equilibria and Thermodynamics #Rheology and Fluid Dynamics Studies #cond-mat.soft #cond-mat.stat-mech #physics.chem-ph
paper · pdf · doi:10.1103/physreve.76.021504
published as Phys. Rev. E 76, 021504 (2007) · 14 pages, 8 figures; v2: some figures redone; small changes
arxiv created 2007/07/04 · openalex publication_date 2007/08/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The two-body interaction in dilute solutions of polymer chains in good solvents can be modeled by means of effective bounded potentials, the simplest of which being that of penetrable spheres (PSs). In this paper we construct two simple analytical theories for the structural properties of PS fluids: a low-temperature (LT) approximation, that can be seen as an extension to PSs of the well-known solution of the Percus-Yevick (PY) equation for hard spheres, and a high-temperature (HT) approximation based on the exact asymptotic behavior in the limit of infinite temperature. Monte Carlo simulations for a wide range of temperatures and densities are performed to assess the validity of both theories. It is found that, despite their simplicity, the HT and LT approximations exhibit a fair agreement with the simulation data within their respective domains of applicability, so that they complement each other. A comparison with numerical solutions of the PY and the hypernetted-chain approximations is also carried out, the latter showing a very good performance, except inside the core at low temperatures.