473009 Density Gradient Theory for Modeling Interfacial Properties of Surfactant Systems
In our work, the interfacial properties of an oil-water-surfactant system were calculated by DGT for the first time. While the conventional DGT algorithm requires a reference substance and can only handle hard sphere molecules, a modified “space stabilized algorithm” is introduced and extended to be applied in a multiphase multicomponent system. This algorithm makes it possible to calculate interfacial properties at any domain size without choosing a reference substance or assuming the functional form of the density profile.
As part of DGT inputs, perturbed chain statistical associating fluid theory (PC-SAFT) equation of state was employed in the calculation, which has an excellent performance in predicting liquid phase properties and phase behavior. The space stabilized algorithm is applied and compared with laboratory data for several mixture systems. The numerical stability analysis is also included in each calculation to verify the reliability of this algorithm for future applications.