Estimation of fluid-fluid interfacial tensions of multicomponent mixtures

Abstract For estimating the gas-liquid interfacial tension (surface tension) of multicomponent liquid mixtures, an equation has been developed from thermodynamics with the local composition concept proposed by Wilson. The equation has been successfully tested for correlating data for a large number of binary systems. With the binary parameters obtained from binary data, the equation has been satisfactorily used to predict the surface tension of ternary and quaternary systems. For estimating liquid-liquid interfacial tension, an equation relating interfacial tension to the equilibrium compositions of the liquid phases has been developed from an interfacial layer model. Using the empirical constant determined by fitting the experimental data to the equation reduced for binary systems, the proposed equation gave satisfactory results for a large number of ternary systems.