Water Vapor Nucleation on a Surface with Nanoscopic Grooves. 2. Features of Thermodynamic Behavior

The Monte Carlo method has been employed to simulate the growth of condensed phase nuclei on a silver iodide crystal surface with parallel nanoscopic grooves having different depths and profiles. The growth thermodynamics has been studied in terms of the free energy, entropy, formation work, and Gibbs free energy calculated for attachment reactions by the bicanonical statistical ensemble method. The grooves decrease the chemical potential of first water molecules attached to the surface by 20k_BT. The grooves present on the surface shift the onset of the nucleation to the region of a rarefied vapor by nearly nine orders of magnitude and increase the thermodynamic stability of the nuclei; however, in the region of moderate values of density, the effect of the grooves is weakened and directed toward the deceleration of the condensation. Fundamental equations have been derived, which represent a generalization of Clapeyron–Clausius equation to the case of condensed phase of nonmacroscopic sizes. Using the aforementioned equations, physical reasons for the regularities observed in the computer simulation have been revealed and the agreement between the numerical results and universal relations that follow from the equations has been analyzed.