Initial Interfacial Tension for Various Organic–Water Systems and Study of the Effect of Solute Concentration and Temperature

Interfacial tension is an important thermophysical property for operations involving multifluid phases such as liquid–liquid extraction. This work aims at presenting a rapid experimental method and initial interfacial tension data of nine organic compounds and water binary systems. The organic compounds include n-butyl acetate, cyclohexanol, cyclohexanone, diethyl ether, ethyl acetate, methyl ethyl ketone, methylcyclohexane, 1-octanol, and toluene. The effect of temperature on the initial interfacial tension was also studied. These systems are chosen to cover a wide range of interfacial tension (1–51 mN/m). Comparisons between the data sets from this work and those from the literature, whenever available, show generally very good agreement. This work also presents new data of initial interfacial tension for several ternary systems with four organic compounds and water with varying quantities of propionic acid or propanoic (0–0.25 mass fraction) at ambient conditions; the organic compounds include n-butyl acetate, cyclohexanone, 1-octanol, and toluene. The results show that the impact of propionic acid concentration as solute in water is large, especially at the higher solute concentrations. The initial and final (mutually saturated phases) interfacial tensions are found in agreement for different immiscible binary systems studied in this work. The method presented may be used as a rapid way of finding interfacial tensions.