Kelvin equation for meniscuses of nanosize dimensions

Curvature corrections to the Kelvin-Laplace equation (KLE) for a highly curved surface and its effect on the general picture of meniscus formation are considered in the frame of a flexural rigidity model of a liquid surface and the Helfrich expression for energy of flexural deformation of the interface. It is shown that the vapor pressure depends not only on surface tension of a liquid but also on flexural properties of the liquid surface. The generalized KLE accounting for the flexural rigidity of the interface explains the observed deviation from the original KLE for meniscuses of nanosize dimensions. The predicted limiting condensation pressure and the limiting curvature radius below, which the meniscus of nanosize dimensions cannot form, is in agreement with surface force apparatus studies.