Mean-Field Approximation to the Hydrophobic Hydration in the Liquid－Vapor Interface of Water
Mean-Field Approximation to the Hydrophobic Hydration in the Liquid－Vapor Interface of Water
复制标题
水液-汽界面疏水水合作用的平均场近似
DOI：
10.1021/acs.jpcb.5b10169
复制
发表时间：
2016
期刊：
影响因子：
3.3
通讯作者：
and K. Koga
中科院分区：
文献类型：
--
作者：
K. Abe;T. Sumi;and K. Koga
提出了非极性溶质在水溶液中的气液界面溶剂化的平均场近似。首先用数值方法描述了甲烷类溶质在大块液态水中的溶剂化过程，其主要思想是在溶质分子中找到空穴的几率(Pcav)和溶质插入这种空穴时所感受到的吸引相互作用能(Uatt)都是溶剂密度的函数。然后假定基本思想在汽液界面仍然有效，但Pavanduatta分别是不同粗晶局部密度的函数，而不是共同的局部密度的函数。对于在253~613K温度范围内类甲烷粒子在模型水界面上的溶剂化，证实了假设的正确性。将平均场近似推广到非均质体系，由单一温度下得到的局部溶解度分布计算了不同温度下界面上的局部溶解度分布。通过直接计算溶剂局域密度变化最快的界面区的过量化学势，预测的分布与直接计算的结果吻合较好。
A mean-field approximation to the solvation of nonpolar solutes in the liquid–vapor interface of aqueous solutions is proposed. It is first remarked with a numerical illustration that the solvation of a methane-like solute in bulk liquid water is accurately described by the mean-field theory of liquids, the main idea of which is that the probability (Pcav) of finding a cavity in the solvent that can accommodate the solute molecule and the attractive interaction energy (uatt) that the solute would feel if it is inserted in such a cavity are both functions of the solvent density alone. It is then assumed that the basic idea is still valid in the liquid–vapor interface, butPcavanduattare separately functions of different coarse-grained local densities, not functions of a common local density. Validity of the assumptions is confirmed for the solvation of the methane-like particle in the interface of model water at temperatures between 253 and 613 K. With the mean-field approximation extended to the inhomogeneous system the local solubility profiles across the interface at various temperatures are calculated fromPcavanduattobtained at a single temperature. The predicted profiles are in excellent agreement with those obtained by the direct calculation of the excess chemical potential over an interfacial region where the solvent local density varies most rapidly.