Interfacial tensions near the critical endpoints and the tricritical point of three-phase equilibria

Prof. Kenichiro Koga

Research Institute for Interdisciplinary Science/Department of Chemistry, Faculty of Science, Okayama University


A mean-field density-functional model with two density variables designed for three-fluid phase equilibria
is analyzed analytically and numerically. The interfacial tension between two phases is found to be given
by an analytic expression that has a geometric interpretation in the space of the two densities.
It is supported by numerical computations of high precision, and it agrees with earlier conjectures obtained
for special cases in the same model. An application is presented to three-phase equilibria in the vicinity
of a tricritical point.