Kinetics of heterogeneous nucleation on a rough surface: Nucleation of a liquid phase in nanocavities

The kinetic theory of heterogeneous nucleation of a liquid developed by Nowakowski and Ruckenstein [J. Phys. Chem. 96 (1992) 2313] for a planar surface is extended to the nucleation of liquid clusters in spherical nanocavities of a solid surface. It is shown that for all considered contact angles and radii of the cavity, the nucleation rate is higher than that on a planar surface and that it increases with increasing strength of the fluid–solid interactions. The difference is small at high supersaturations (small critical clusters), but is orders of magnitude higher at lower supersaturations when the cluster has a size comparable with the size of the cavity. At constant contact angle the nucleation rate increases with increasing curvature of the cavity. The dependence of the nucleation rate on the contact angle is not monotonous.

Nucleation rate as function of supersaturation s for cavities of various radii Rs and for planar surface.Figure optionsDownload high-quality image (66 K)Download as PowerPoint slideResearch highlights
► Kinetic theory of nucleation (Ruckenstein, Narsimhan, and Nowakowski) is extended to the nucleation in cavities.
► The rate of nucleation in cavities is many orders of magnitude larger than that on a planar solid surface.
► The nucleation rate increases with decreasing cavity radius and with increasing strength of solid-fluid interaction.