Modeling the temperature dependent interfacial tension between organic solvents and water using dissipative particle dynamics

The interfacial tension between organic solvents and water at different temperatures is predicted using coarse-grained, mesoscopic Dissipative Particle Dynamics (DPD) simulations. The temperature effect of the DPD repulsive interaction parameters, a(ij), for the different components is calculated from the dependence of the Flory-Huggins rho parameter on temperature, by means of the solubility parameters. Atomistic simulations were carried out for the calculation of the solubility parameters for different organic compounds at different temperatures in order to estimate chi and then the a(ij) coefficients. We validate this parametrization through the study of the interfacial tension in a mixture of benzene and water, and cyclohexane and water, varying the temperature. The predictions of our simulations are found to be in good agreement with experimental data taken from the literature, and show that the use of the solubility parameter at different temperatures to obtain the repulsive DPD parameters is a good alternative to introduce the effect of temperature in these systems. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793742]