Investigation of surface tension and interfacial tension in surfactant solutions by SAFT

A primitive model for surface and interfacial tension in surfactant systems is developed on the basis of the statistical associating fluid theory (SAF T). The mean spherical approximation (MSA) is applied to describe the ion-i on interaction in this model. The surface and interfacial tensions for five surfactant systems are measured in the range 21-50 degrees C. The experime ntal data obtained at 25 degrees C and the surface tensions of CxEy-water s ystems from literature are correlated. The surface and interfacial tensions of these systems up to 50 degrees C are predicted by the parameters obtain ed from correlation. Both the correlated and predicted results are satisfac tory.