Prediction of Surface Tension Using COSMO-RS

We developed a method for predicting surface tension using COSMO-RS. It is based on an empirical correction to the COSMO-RS-based method for predicting liquid–liquid interfacial tension. The method developed here allows for the predictions of surface tension and interfacial tension of gas–liquid systems from low to high pressures and gives good agreement with experiments for the surface tension of more than 50 single component liquids and 12 binary mixtures, including three surfactant solutions (one cationic, one anionic, and one nonionic). The mean absolute deviation for the single component surface tension predictions was <4 mN/m, and the average relative deviation was 11%. The maximum deviations were about −9 and +9 mN/m, which correspond to a maximum relative deviation of 28%. The temperature dependence of surface tension for several polar and nonpolar compounds was also well reproduced as was the general behavior of surfactants.