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Macroion correlation effects in electrostatic screening and thermodynamics of highly charged colloids

Ramon Castaneda-Priego·Luis F. Rojas-Ochoa·Vladimir Lobaskin·J. C. Mixteco-Sanchez
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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.

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Ramon Castaneda-Priego, Luis F. Rojas-Ochoa, Vladimir Lobaskin, J. C. Mixteco-Sanchez. 2006-08-07. Macroion correlation effects in electrostatic screening and thermodynamics of highly charged colloids. https://doi.org/10.1103/physreve.74.051408

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