Mean-field kinetic nucleation theory

Area of Science:

• Physical Chemistry
• Thermodynamics
• Materials Science

Background:

• Classical nucleation theory often fails to accurately predict experimental results, especially when critical clusters are small.
• Existing models struggle with non-perturbative descriptions of cluster kinetics and thermodynamics.

Purpose of the Study:

• To propose a new semiphenomenological model for homogeneous vapor-liquid nucleation.
• To develop a theory valid for all cluster sizes, from monomers to macroscopic clusters.
• To improve the prediction accuracy of nucleation phenomena in various fluids.

Main Methods:

• The model integrates the kinetic approach to nucleation with a revised Fisher droplet model.
• It incorporates a mean-field argument for the cluster configuration integral.
• The theory accounts for both macroscopic and microscopic surface tensions, with the latter being temperature-dependent.

Main Results:

• The proposed theory is nonperturbative with respect to cluster size, offering validity down to monomers.
• Microscopic surface tension exhibits universal behavior for Lennard-Jones fluids, derived from mean-field density functional calculations.
• Excellent agreement was achieved between the model's predictions and experimental nucleation data for argon, nitrogen, water, and mercury.

Conclusions:

• The new semiphenomenological model provides a more accurate description of homogeneous vapor-liquid nucleation compared to classical theories.
• The model's ability to handle small critical clusters and its validation across multiple substances highlight its robustness.
• This work advances the understanding of nucleation processes and offers a reliable tool for predicting experimental outcomes.