Specific volume and entropy of the formation of the interface between two immiscible liquids

A rigorous thermodynamic definition is given for the specific characteristics of interface formation: volume, entropy, and energy. The characteristics are calculated by the Hansen method. It is shown that the specific characteristics of interface formation coincide with the coefficients of the Gibbs adsorption equation in the Hansen representation, only for the simplest case of a two-component two-phase system. In general, a system of equations is derived for determining the specific characteristics, and its solution is found for some of the most important particular cases, say, for a three-component two-phase system. These results are compared with other approaches which are not general enough and have strong limitations.