Study of Interfacial Tension between an Organic Solvent and Aqueous Electrolyte Solutions Using Electrostatic Dissipative Particle Dynamics Simulations

TL;DR

This paper uses electrostatic Dissipative Particle Dynamics simulations to study interfacial tension between organic solvents and aqueous electrolyte solutions, incorporating activity coefficient-based parametrization for improved accuracy.

Contribution

It introduces a new parametrization method for DPD simulations using activity coefficients to determine electrolyte interaction parameters, validated against experimental interfacial tension data.

Findings

Simulation results agree well with experimental data.

Activity coefficient-based parametrization improves DPD accuracy.

Method applicable to various electrolyte solutions.

Abstract

The study of the modification of interfacial properties between an organic solvent and aqueous electrolyte solutions is presented by using electrostatic Dissipative Particle Dynamics (DPD) simulations. In this article the parametrization for the DPD repulsive parameters aij for the electrolyte components is calculated considering the dependence of the Flory-Huggins \c{hi} parameter on the concentration and the kind of electrolyte added, by means of the activity coefficients. In turn, experimental data was used to obtain the activity coefficients of the electrolytes as a function of their concentration in order to estimate the \c{hi} parameters and then the aij coefficients. We validate this parametrization through the study of the interfacial tension in a mixture of n-dodecane and water, varying the concentration of different inorganic salts (NaCl, KBr, Na2SO4 and UO2Cl2). The case of HCl in the mixture n-dodecane/water was also analyzed and the results presented. Our simulations reproduce the experimental data in good agreement with previous work, showing that the use of activity coefficients to obtain the repulsive DPD parameters aij as a function of concentration is a good alternative for these kinds of systems.