Ionic activity in concentrated electrolytes: solvent structure effect revisited
Chemical Physics
2020-01-08 v1 Soft Condensed Matter
Abstract
We revisit the role of the local solvent structure on the activity coefficient of electrolytes with a general non-local dielectric function approach. We treat the concentrated electrolyte as a dielectric medium and suggest an interpolated formula for the dielectric response. The pure water limit is calibrated based on MD simulations and experimental data. Solving our model around a central ion, we find strong over-screening and oscillations in the potential, which are absent in the standard "primitive model" predictions. We obtain mathematically tractable closed-form expressions for the activity coefficients and show reasonable agreement with experimental data.
Cite
@article{arxiv.1905.12076,
title = {Ionic activity in concentrated electrolytes: solvent structure effect revisited},
author = {Amir Levy and Martin Z. Bazant and Alexei A. Kornyshev},
journal= {arXiv preprint arXiv:1905.12076},
year = {2020}
}