Study of interfacial tension between an organic solvent and aqueous electrolyte solutions using electrostatic dissipative particle dynamics simulations

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 a(ij) for the electrolyte components is calculated considering the dependence of the Flory-Huggins χ parameter on the concentration and the kind of electrolyte added, by means of the activity coefficients. In turn, experimental data were used to obtain the activity coefficients of the electrolytes as a function of their concentration in order to estimate the χ parameters and then the a(ij) 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, Na(2)SO(4), and UO(2)Cl(2)). 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 a(ij) as a function of concentration is a good alternative for these kinds of systems.