Nucleation on Strongly Curved Surfaces of Nanofibers

Abstract

It is well known that the existence of the energy barrier of nucleation is a result of the interplay of two antagonistic tendencies: an endeavor of the system to go from initial metastable phase to a more favorable one, and a general trend to minimize the area of interfaces between different phases in the system. The former leads to a negative volume contribution $\Delta {G_{\text{V}}}$ to the total Gibbs free energy of the cluster formation $\Delta G$, whereas the latter corresponds to the positive surface contribution $\Delta {G_{\text{S}}}$:

$$ \Delta G = \Delta {G_{\text{V}}} + \Delta {G_{\text{S}}} = - n\Delta \mu + \gamma \sigma {n^{2/3}}, $$

(19.1)

where $\Delta \mu$ is the difference of the chemical potentials of the initial metastable and the newly growing phases, n is the number of building units in the cluster, σ is the excess surface energy, and γ stands for the shape factor, which describes the ratio of the surface area of the cluster to its volume.