Interfacial Energy and the Law of Corresponding States

摘要

An extension of the mesoscopic model previously developed for fluid/liquid interfaces [J. Phys. Chem. A 2003, 107, 875; 2003, 107, 883] is presented. The formalism is applied here to the vapor/liquid interface of nonpolar compounds. The treatment takes into consideration the nonuniform nature of the interfacial region and the mechanisms through which its excess energy is reversibly stored. Arguments are given in favor of using the interfacial energy (instead of the interfacial tension) in the scheme of corresponding states. To calculate the free energy accumulated at the interface, an expression for the interfacial area of the molecules becomes necessary. A temperature-dependent expression for this variable based on the projection of the molecular area on the interface is implemented. The resulting correlation has an average absolute deviation for the interfacial tension of only 0.5% for 62 representative organic compounds.