Steady-State Homogeneous Nucleation and Growth of Water Droplets: Extended Numerical Treatment

TL;DR

This study uses advanced molecular dynamics simulations to analyze water droplet nucleation and growth, providing detailed thermodynamic and kinetic insights across a range of temperatures, and compares results with classical nucleation theory.

Contribution

It introduces an extended numerical approach combining thermodynamic integration and mean first passage time methods to study water droplet nucleation and growth in detail.

Findings

Liquid droplet growth is unsteady and follows a power law.

Surface tension estimates agree with experimental data.

Nucleation characteristics are consistent across temperatures.

Abstract

The steady-state homogeneous vapor-to-liquid nucleation and the succeeding liquid droplet growth process are studied for water system by means of the coarse-grained molecular dynamics simulations with the mW-model suggested originally in [Molinero, V.; Moore, E. B. \textit{J. Phys. Chem. B} \textbf{2009}, \textit{113}, 4008-4016]. The investigation covers the temperature range $273 \leq T/K \leq 363$ and the system's pressure $p\simeq 1$ atm. The thermodynamic integration scheme and the extended mean first passage time method as a tool to find the nucleation and cluster growth characteristics are applied. The surface tension is numerically estimated and is compared with the experimental data for the considered temperature range. We extract the nucleation characteristics such as the steady-state nucleation rate, the critical cluster size, the nucleation barrier, the Zeldovich factor; perform the comparison with the other simulation results and test the treatment of the simulation results within the classical nucleation theory. We found that the liquid droplet growth is unsteady and follows the power law. At that, the growth laws exhibit the features unified for all the considered temperatures. The geometry of the nucleated droplets is also studied.