Macroion correlation effects in electrostatic screening and thermodynamics of highly charged colloids
Abstract
We study macroion correlation effects on the thermodynamics of highly charged colloidal suspensions using a mean-field theory and primitive model computer simulations. We suggest a simple way to include the macroion correlations into the mean-field theory as an extension of the renormalized jellium model of Trizac and Levin [Phys. Rev. E {\bf 69}, 031403 (2004)]. The effective screening parameters extracted from our mean-field approach are then used in a one-component model with macroions interacting via Yukawa-like potential to predict macroion distributions. We find that inclusion of macroion correlations leads to a weaker screening and hence smaller effective macroion charge and lower osmotic pressure of the colloidal dispersion as compared to other mean-field models. This result is supported by a comparison to primitive model simulations and experiments for charged macroions in the low-salt regime, where the macroion correlations are expected to be significant.
Keywords
Cite
@article{arxiv.cond-mat/0608163,
title = {Macroion correlation effects in electrostatic screening and thermodynamics of highly charged colloids},
author = {Ramon Castaneda-Priego and Luis F. Rojas-Ochoa and Vladimir Lobaskin and J. C. Mixteco-Sanchez},
journal= {arXiv preprint arXiv:cond-mat/0608163},
year = {2009}
}