Molecular Dynamics simulations of concentrated aqueous electrolyte solutions

TL;DR

This study uses molecular dynamics simulations to analyze transport properties of concentrated aqueous electrolytes, including conductivity, transport numbers, and electroosmotic flow, comparing results with experimental data.

Contribution

It provides detailed simulation data on various electrolyte solutions, including monovalent, divalent, and trivalent ions, and interprets electroosmotic flow based on hydration properties.

Findings

Simulated electrical conductivities match experimental values.

Transport numbers vary with electrolyte composition and electric field strength.

Electroosmotic flow correlates with hydration shell dynamics.

Abstract

Transport properties of concentrated electrolytes have been analyzed using classical molecular dynamics simulations with the algorithms and parameters typical of simulations describing complex electrokinetic phenomena. The electrical conductivity and transport numbers of electrolytes containing monovalent (KCl), divalent (MgCl$_2$), a mixture of both (KCl + MgCl$_2$), and trivalent (LaCl$_3$) cations have been obtained from simulations of the electrolytes in electric fields of different magnitude. The results obtained for different simulation parameters have been discussed and compared with experimental measurements of our own and from the literature. The electroosmotic flow of water molecules induced by the ionic current in the different cases has been calculated and interpreted with the help of the hydration properties extracted from the simulations.