Vapor Nucleation and Droplet Growth: Cluster Distribution Kinetics for Open and Closed Systems

Area of Science:

• Physical Chemistry
• Materials Science
• Chemical Engineering

Background:

• Classical nucleation theory often shows discrepancies with experimental data, especially concerning temperature dependence.
• Understanding vapor nucleation and growth dynamics is crucial for various industrial processes and atmospheric science.

Purpose of the Study:

• To present a new theoretical framework for homogeneous and heterogeneous vapor nucleation and growth dynamics.
• To develop a model based on cluster distribution kinetics, including single-monomer addition and dissociation.
• To resolve the temperature-dependent discrepancies observed between experimental nucleation data and classical theories.

Main Methods:

• Developed a theory based on cluster distribution kinetics for single-monomer addition and dissociation.
• Utilized population (mass) balance equations to derive moment equations for cluster mass moments in continuous distributions.
• Proposed solutions for both steady-state flow (open) and non-steady-state batch (closed) systems.

Main Results:

• The zeroth, first, and second moments of cluster mass distributions represent number, mass, and size variance, respectively.
• The model accounts for nuclei being homogeneously generated or heterogeneously seeded, followed by reversible condensation.
• Interpreted experimental data by considering that observed droplets are significantly larger than their initial nuclei.

Conclusions:

• The proposed theory provides a framework that reconciles experimental observations with theoretical predictions in nucleation phenomena.
• The model successfully resolves the long-standing temperature-dependent discrepancy between experimental data and classical nucleation theory.
• This kinetic cluster-based approach offers a more accurate description of vapor nucleation and growth dynamics.