ESTIMATION OF INTERFACIAL-TENSIONS OF TERNARY LIQUID LIQUID-SYSTEMS BY UNIQUAC METHOD

Based on the model of liquid-liquid interface phase of a monolayer of molecules, a method used to predict the liquid-liquid interfacial tensions of ternary systems by the UNIQUAC method has been developed. In the method the interfacial tension is determined by two contributions, one depends on the compositions in the two bulk liquid phases and the interface phase and another arises from the concentration differences between the interface phase and the bulk phases. The UNIQUAC equation and its parameters are used respectively in the calculation of the two contributions. The experimental data of interfacial tension for the partially miscible pair in a ternary system is needed to determine the partial molar interfacial areas of the components included in the system. The method enables the prediction of interfacial tension to within an overall average absolute deviation of 1.6 mN / m for 33 ternary systems with the interfacial tension of the partially miscible pair included in the systems being less than 40 mN / m.