Research Reactor Services Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
J Chem Phys. 2013 Aug 7;139(5):054702. doi: 10.1063/1.4817197.
Vapor to liquid condensation in presence of spherical seed particle of any arbitrary radius ranging from zero to infinity has been investigated using density functional theory, by modeling the local Helmholtz free energy density functional as well as the density profile at the vapor-liquid interface. A general theory is, thus, obtained which provides the different modes of nucleation based on the size of the seed ranging from zero (corresponding to the homogeneous mode of nucleation) to infinity (corresponding to the heterogeneous nucleation on flat surface). The theory is applied to the Lennard-Jones fluid and the optimized shape (i.e., contact angle) and formation free energy of droplets of any arbitrary size have been obtained in this work. The change of the shape (optimized) with the variation of the size of the liquid droplet as well as with the size of the solid substrate has been studied, thus predicting the shape-size relationship in the course of vapor to liquid heterogeneous nucleation on a spherical solid substrate of any particular size. The spinodal decomposition of vapor has also been observed at higher strength of the solid-fluid interaction. The results have been compared with the results of the conventional classical nucleation theory.
采用密度泛函理论，通过对局部亥姆霍兹自由能密度泛函以及汽液界面处的密度分布进行建模，研究了任意半径（从零到无穷大）球形种子颗粒存在时的蒸汽到液体的冷凝。因此，得到了一种通用理论，该理论根据种子的大小（从零（对应于均匀成核模式）到无穷大（对应于平面上的异质成核））提供了不同的成核模式。该理论应用于 Lennard-Jones 流体，并且在这项工作中获得了任意大小液滴的优化形状（即接触角）和形成自由能。研究了形状（优化）随液滴尺寸以及固体基底尺寸的变化，从而预测了在特定尺寸的球形固体基底上蒸汽到液体异质成核过程中的形状-尺寸关系。在较强的固-液相互作用下，也观察到了蒸汽的旋节分解。将结果与传统经典成核理论的结果进行了比较。
