Modification of the classical nucleation theory based on molecular simulation data for surface tension, critical nucleus size, and nucleation rate

TL;DR

This paper uses molecular dynamics simulations to analyze nucleation in supersaturated vapor, revealing limitations of classical nucleation theory and proposing a surface property corrected modification for better accuracy.

Contribution

It introduces a modified classical nucleation theory incorporating surface property corrections based on molecular simulation data.

Findings

Classical theory underestimates nucleation rate and critical nucleus size.

Proposed modification aligns theory with simulation data on surface tension and nucleation.

Enhanced model improves understanding of nucleation processes in Lennard-Jones fluids.

Abstract

Nucleation in supersaturated vapor is investigated with two series of molecular dynamics simulations in the canonical ensemble. The applied methods are: (a) analysis of critical nuclei at moderate supersaturations by simulating equilibria of single droplets with surrounding vapors in small systems; (b) simulation of homogeneous nucleation during condensation with large systems containing 10^5 to 10^6 particles for calculating the nucleation rate of vapors at high supersaturations. For the Lennard-Jones fluid, truncated and shifted at 2.5 times the size parameter, it is shown that the classical nucleation theory underestimates both the nucleation rate and the size of the critical nucleus. A surface property corrected modification of this theory is proposed to consistently cover data on the surface tension of the curved interface, the critical nucleus size, and the nucleation rate.