Effective interactions in polydisperse systems of penetrable macroions

Author(s)
Thiago Colla, Christos N. Likos
Abstract

A coarse-graining approach based on the linear response theory is applied to deduce general expressions for the effective pair potentials in a multi-component system of soft macroions. Within the underlying approximations, the effective pair potentials can be written as simple convolutions between the intrinsic macroion charge distributions and a Yukawa-like potential which effectively contains the averaged contributions from the small ions. Two different charge distributions are assigned to the soft macroions: a Gaussian-like diffuse distribution and a uniform charge distribution inside the particle cores. The resulting effective pair potentials are then used in an effective model based on the hyppernetted chain approximation to investigate the structural properties of a two-component system of oppositely charged particles as a function of the various system parameters. It is found that the condensation of counterions is much stronger in the case of particles with a Gaussian charge distribution, leading to much weaker electrostatic interactions and less structured pair correlations in comparison with the system of uniformly charged macroions.

Organisation(s)
Computational and Soft Matter Physics
External organisation(s)
University of Vienna
Journal
Molecular Physics: an international journal in the field of chemical physics
Volume
113
Pages
2496-2510
No. of pages
15
ISSN
0026-8976
DOI
https://doi.org/10.1080/00268976.2015.1026295
Publication date
09-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103036 Theoretical physics, 103015 Condensed matter, 103029 Statistical physics
Keywords
ASJC Scopus subject areas
Condensed Matter Physics, Molecular Biology, Biophysics, Physical and Theoretical Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/a3c3893e-874d-4174-b8f2-d949cd5f4fb7