互饱和水/正丁醇溶液的气液界面性质。

Vapor-liquid interfacial properties of mutually saturated water/1-butanol solutions.

作者信息

Chen Bin, Siepmann J Ilja, Klein Michael L

机构信息

Center for Molecular Modeling and Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.

出版信息

J Am Chem Soc. 2002 Oct 16;124(41):12232-7. doi: 10.1021/ja027130n.

DOI:10.1021/ja027130n

PMID:12371864

Abstract

Adsorption and ordering at the vapor-liquid interfaces of mutually saturated water/1-butanol solutions at a temperature of 298.15 K were investigated using configurational-bias Monte Carlo simulations in the Gibbs ensemble and compared to the surface properties of neat water and 1-butanol liquids. A dense 1-butanol monolayer is observed at the surface of the water-rich phase, which results in a substantial decrease of its surface tension. In contrast, there is no enrichment of water molecules at the surface of the butanol-rich phase, and its surface tension is not significantly changed. Analysis of the interfacial structures reveals that these systems exhibit orientational ordering and composition heterogeneity. Analysis of the hydrogen-bonding distributions suggests that the formation of the 1-butanol monolayer is driven by an excellent match between water and the primary alcohol; that is, additional hydrogen bonds are formed between the excess free hydrogens of surface water and the excess hydrogen-bond acceptor sites of 1-butanol.

摘要

利用吉布斯系综中的构型偏倚蒙特卡罗模拟，研究了在298.15 K温度下相互饱和的水/正丁醇溶液气液界面的吸附和有序排列，并与纯水和正丁醇液体的表面性质进行了比较。在富水相表面观察到致密的正丁醇单分子层，这导致其表面张力大幅降低。相反，在富丁醇相表面没有水分子富集，其表面张力没有明显变化。界面结构分析表明，这些体系表现出取向有序和组成不均匀性。氢键分布分析表明，正丁醇单分子层的形成是由水与伯醇之间的良好匹配驱动的；也就是说，表面水的过量游离氢与正丁醇的过量氢键受体位点之间形成了额外的氢键。