Chapter 5 - Nucleation theorem

Abstract

Depending on the concrete model for the nucleus shape and size, in the various cases of nucleation, the nucleation work (W*) and the nucleus size (n*) are different functions of supersaturation (∆μ). However, the classical theory provides the rather general expressions that relate W*, n*, and ∆μ in the considered cases of equimolecular dividing surface (EDS)-defined 3D and 2D nuclei of condensed phases regardless of the assumed nucleus shape. This is a signal that there can exist a more general, model-independent relationship among W*, n*, and ∆μ. However, it is not applicable to bubble nucleation. Moreover, it is valid only for EDS-defined nuclei, and in this sense its generality is limited. A most general formula must connect W* and ∆μ, which are invariants with respect to the choice of the dividing surface, with a quantity which, in contrast to n*, does not depend on this choice. The nucleation theorem represents such a universal relationship between the nucleation work and the nucleus size.