Molecular Dynamics Studies on the Effect of Surface Roughness and Surface Tension on the Thermodynamics and Dynamics of Hydronium Ion Transfer Across the Liquid/Liquid Interface
Molecular Dynamics Studies on the Effect of Surface Roughness and Surface Tension on the Thermodynamics and Dynamics of Hydronium Ion Transfer Across the Liquid/Liquid Interface
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DOI：
10.1021/acs.jpcb.0c06304
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发表时间：
2020-10-01
影响因子：
3.3
通讯作者：
Benjamin, Ilan
中科院分区：
文献类型：
--
作者：
Benjamin, Ilan
采用分子动力学模拟研究了表面粗糙度和表面张力对经典水合氢离子（h30 +）在水/1,2-二氯乙烷界面上转移的影响。自由传递能、水化结构和动力学作为离子沿界面法向位置的函数计算了六个不同的控制参数值，其变化改变了表面张力，而不影响两种溶剂的体积性质。经典水合氢离子在水/1,2-二氯烷界面上的转移涉及三个水合壳水分子的共转移，与表面张力无关。然而，随着两种液体之间的相互作用减弱，界面张力升高，固有水指动和毛细波动减少，导致第二壳层中与离子共运的水分子减少，离子附着的指的长度减少，这与第二水化壳的尺寸减小相一致。首先，壳水停留时间和横向离子扩散常数随表面张力的变化而变化，这与上述结构观点一致。
Molecular dynamics simulations are used to examine the effect of surface roughness and surface tension on the transfer of the classical hydronium ion (H3O+) across the water/1,2-dichloroethane interface. Free energy of transfer, hydration structure, and dynamics as a function of the ion location along the interface normal are calculated with six different values of a control parameter whose variation modifies the surface tension without impacting the bulk properties of the two solvents. Transfer of the classical hydronium ion across the water/1,2-dichloroethan interface involves the cotransfer of three hydration shell water molecules, independent of the surface tension. However, as the interaction between the two liquids weakens, a rise in interfacial tension and decrease in intrinsic water fingering and capillary fluctuations result in fewer water molecules cotransported with the ion in the second shell and a reduction in the length of the finger that the ion is attached to, consistent with the reduced size of the second hydration shell. First shell water residence time and lateral ion diffusion constants vary with the surface tension in a way that is consistent with the abovementioned structural insight.