Kinetic theory of diffusion-limited nucleation

T. Philippe (1) , M. Bonvalet (2) , D. Blavette (3)

1 PMC - Physique de la Matière Condensée
2 KTH - Department of Materials Science and Engineering, KTH
3 GPM - Groupe de physique des matériaux

We examine binary nucleation in the size and composition space \R,c\ using the formalism of the multivariable theory [N. V. Alekseechkin, J. Chem. Phys. 124, 124512 (2006)]. We show that the variable c drops out of consideration for very large curvature of the new phase Gibbs energy with composition. Consequently nuclei around the critical size have the critical composition, which is derived from the condition of criticality for the canonical variables and is found not to depend on surface tension. In this case, nucleation kinetics can be investigated in the size space only. Using macroscopic kinetics, we determine the general expression for the condensation rate when growth is limited by bulk diffusion, which accounts for both diffusion and capillarity and exhibits a different dependence with the critical size, as compared with the interface-limited regime. This newexpression of the condensation rate for bulk diffusion-limited nucleation is the counterpart of the classical interface-limited result.We then extend our analysis to multicomponent solutions. Published

Domaines: Physique [physics]

T. Philippe, M. Bonvalet, D. Blavette. Kinetic theory of diffusion-limited nucleation. Journal of Chemical Physics, 2016, 144 (20), ⟨10.1063/1.4950878⟩. ⟨hal-01928846⟩