Prewetting and density fluctuations in the prewetting supercritical phase

摘要

By means of Monte Carlo simulations, we investigate prewetting and its supercritical phase. First, we examine several fluid-substrate interaction parameters, and discuss the general properties of prewetting. We locate a prewetting line for each parameter and obtain global phase diagrams. Secondly, we study the prewetting supercritical phase, in which density fluctuations in a film play an important role. From the structure factors of the first adsorption layer, we derive isotherms of two-dimensional compressibility and the extension of the prewetting line defined by mapping out the locus of points at which the compressibility attains its maximum value. It is shown that the prewetting line and its extension bend one another at the prewetting critical point. Our results lend support to recent mercury-on-sapphire experiments. [References: 27]