Modeling of the surface tension of pure components and mixtures using the density gradient theory combined with a theoretically derived influence parameter correlation

In this work surface tensions are calculated by combining the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) with the Density Gradient Theory of inhomogeneous fluid interfaces. Important parameters in the density gradient theory are the so-called influence parameters. A correlation is developed to estimate these influence parameters using their theoretical definition as a starting point. It is shown that the developed correlation in combination with the density gradient theory gives good predictions of surface tensions for pure components as well as binary and ternary mixtures with hydrocarbons.