The effect of system volume limitation on the surface tension of a vapor–liquid interface

The effect of the system volume limitation on the thermodynamic characteristics of a vapor–liquid interface, that is, the phase states of a substance and the surface tension, is considered. The molecular theory is used based on the lattice gas model, which describes the two-phase state of a vapor–liquid system. To simplify the calculations, the molecular characteristics of the spherical interface of a drop inside a spherical region of vapor having a single dimensional parameter, namely, the radius of the system, are assessed. It is found that, when the radius of the system decreases, the critical temperature decreases, while the internal pressure, the chemical potential, and the surface tension increase.