On the IInterfacial Behavior about the Shield Region

The shield region is a singular range of the global phase diagram (GPD), where equations of state based on mean-field theories predict a quadruple point (QP) for fluid binary mixtures. The QP in question is characterized by three immiscible liquids and a vapor in equilibrium. No experimental system has been found exhibiting such an equilibrium behavior. In this theoretical study the iInterfacial and wetting behavior of the phases that coexist at the QP by applying the gradient theory to the van der Waals equation of state is described.