An interfacial statistical associating fluid theory (iSAFT) approach for surface/interfacial tension predictions

Interfacial properties play an important role in many industrial processes and in the design of new materials. A fundamental understanding of interfacial phenomena and predictive tools that predict interfacial properties can greatly facilitate new process/material design. In this work, we propose an extension to the original interfacial Statistical Associating Fluid Theory (iSAFT) by Tripathi and Chapman [1]. This resulting classical Density Functional Theory (DFT) reduces to PC-SAFT equation of state in the bulk limit. It accepts PC-SAFT parameter values as input and predicts interfacial properties. The model is applied to vapor-liquid interfaces and liquid-liquid interfaces of both non-associating and associating fluids and the predicted surface/interfacial tensions agree very well with experimental data.