Kinetic theory of binary nucleation based on a first passage time analysis

Area of Science:

• Physical Chemistry
• Chemical Engineering
• Materials Science

Background:

• Classical nucleation theories rely on macroscopic thermodynamics, leading to inaccuracies for nanoscale systems.
• Binary classical nucleation theory (BCNT) exhibits significant discrepancies with experimental nucleation rates.
• Existing models struggle with systems containing surface-active components.

Purpose of the Study:

• To develop a novel kinetic theory for binary nucleation that bypasses classical thermodynamics.
• To provide a more accurate theoretical framework for nucleation phenomena in binary mixtures.
• To address the limitations of BCNT, particularly for systems with surface-active molecules.

Main Methods:

• Extended existing kinetic theory for unary nucleation to binary mixtures.
• Utilized mean first passage time analysis to determine molecular emission rates from clusters.
• Integrated density functional theory (DFT) to calculate accurate density profiles.
• Solved master equations (Fokker-Planck and Smoluchowski) for molecular dynamics.

Main Results:

• Developed a new kinetic theory applicable to binary nucleation, avoiding Gibbsian thermodynamics for clusters.
• Demonstrated improved accuracy in predicting nucleation rates, especially for binary mixtures with surface-active components.
• Numerical simulations on Lennard-Jones mixtures validated the new theory's effectiveness.

Conclusions:

• The novel kinetic theory offers a more robust and accurate approach to binary nucleation.
• The method overcomes inconsistencies associated with BCNT, particularly in complex mixtures.
• Accurate density profiling is crucial for precise nucleation rate predictions in binary systems.