Free energy calculations along entropic pathways. II. Droplet nucleation in binary mixtures
Free energy calculations along entropic pathways. II. Droplet nucleation in binary mixtures
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DOI：
10.1063/1.4972011
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发表时间：
2016-12-21
影响因子：
4.4
通讯作者：
Delhommelle, Jerome
中科院分区：
文献类型：
--
作者：
Desgranges, Caroline;Delhommelle, Jerome
使用分子模拟，我们研究二元混合物中液滴的成核，并确定沿熵路径成核的自由能。为此，我们开发了基于对二元混合物进行建模的大正则系综的mu(1)mu 2VT-S方法，并使用系统的熵S作为反应坐标来驱动液滴的形成。这种方法建立在大正则系综的优点之上，它允许直接计算系统的熵，并让系统的组成在整个成核过程中自由变化。从亚稳态过饱和蒸气开始，我们可以通过逐渐减小 S 值，通过一系列伞式采样模拟来形成液滴，直到形成临界尺寸的液滴。 mu(1)mu 2VT-S方法还允许我们计算与成核过程相关的自由能势垒，揭示过饱和度和成核自由能之间的关系，并分析成核过程中液滴尺寸与其成分之间的相互作用。由 AIP 出版社出版。
Using molecular simulation, we study the nucleation of liquid droplets from binary mixtures and determine the free energy of nucleation along entropic pathways. To this aim, we develop the mu(1)mu 2VT-S method, based on the grand-canonical ensemble modeling the binary mixture, and use the entropy of the system S as the reaction coordinate to drive the formation of the liquid droplet. This approach builds on the advantages of the grand-canonical ensemble, which allows for the direct calculation of the entropy of the system and lets the composition of the system free to vary throughout the nucleation process. Starting from a metastable supersaturated vapor, we are able to form a liquid droplet by gradually decreasing the value of S, through a series of umbrella sampling simulations, until a liquid droplet of a critical size has formed. The mu(1)mu 2VT-S method also allows us to calculate the free energy barrier associated with the nucleation process, to shed light on the relation between supersaturation and free energy of nucleation, and to analyze the interplay between the size of the droplet and its composition during the nucleation process. Published by AIP Publishing.