Phase behavior and interfacial tensions in the ternary systems water + dodecane + propylene glycol n-propyl ether and water + tetradecane + propylene glycol n-propyl ether

Abstract

Fish-shaped phase diagrams at a fixed water/oil mass ratio (1/1) were measured under atmospheric pressure and were used to determine the upper and lower critical solution temperatures of the ternary systems: water+dodecane+propylene glycol n-propyl ether and water+tetradecane+propylene glycol n-propyl ether. In-between the upper and lower critical solution temperatures the system falls into the three-liquid-phase-coexisting region. Interfacial tensions and densities were measured in the three-liquid-phase-coexisting region of these two ternary systems. Interfacial tensions were used to determine the wetting coefficient which was used to identify the wetting behavior. For these two ternary systems, the middle liquid phase always exhibits complete wetting behavior at the interface separating the upper and lower liquid phases over the temperature window of the three-liquid-phase-coexisting region.