Bulk and Interfacial Properties of Polymers from Interfacial SAFT Density Functional Theory

Bulk and interfacial properties of n-alkanes and polymers are modeled in the framework of the interfacial statistical associating fluid theory (iSAFT) density functional theory (DFT). The theory reduces to an equivalent of the SAFT equation of state in the bulk, thus making possible the modeling of both bulk and interfacial properties with a single set of parameters. The performance of iSAFT is illustrated through comparisons of the theory predictions with molecular simulation as well as experimental data for vapor-liquid surface tension. The formulation of iSAFT DFT preserves the computational efficiency of an atomic DFT, thus enabling the theory to deal with molecules comprising hundreds or even thousands of segments, such as the polystyrene and polyethylene included in the present work.