Department of Physics, Kazan Federal University, Kazan, Russia.
J Phys Chem B. 2012 Oct 4;116(39):11959-67. doi: 10.1021/jp304830e. Epub 2012 Sep 25.
The steady-state homogeneous vapor-to-liquid nucleation and the succeeding liquid droplet growth process are studied for water systems by means of the coarse-grained molecular dynamics simulations with the mW model suggested originally by Molinero et al. [Molinero, V.; Moore, E. B. J. Phys. Chem. B 2009, 113, 4008-4016]. The investigation covers the temperature range 273 ≤ T/K ≤ 363 and the system's pressure p ~/= 1 atm. The thermodynamic integration scheme and the extended mean first passage time method as tools 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, and the Zeldovich factor and 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. Also, the growth laws exhibit the features unified for all of the considered temperatures. The geometry of the nucleated droplets is also studied.
通过使用 Molinero 等人最初提出的粗粒分子动力学模拟 mW 模型,研究了水体系的稳态均相气相到液相成核和随后的液滴生长过程。[Molinero,V.;摩尔,E. B. J. Phys. Chem. B 2009,113,4008-4016]。研究涵盖了温度范围 273 ≤ T/K ≤ 363 和系统压力 p ~/= 1 atm。应用热力学积分方案和扩展平均首次通过时间方法来寻找成核和团簇生长特性。数值估计了表面张力,并将其与考虑温度范围内的实验数据进行了比较。我们提取了成核特性,如稳态成核率、临界团簇大小、成核势垒和 Zeldovich 因子,并与其他模拟结果进行了比较,检验了经典成核理论中模拟结果的处理。我们发现液滴生长是不稳定的,遵循幂律。此外,生长规律表现出所有考虑温度的统一特征。还研究了成核液滴的几何形状。