Structure and dynamics of water on muscovite mica surfaces
Structure and dynamics of water on muscovite mica surfaces
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DOI：
10.1016/j.gca.2009.05.029
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发表时间：
2009-07-15
影响因子：
5
通讯作者：
Kawamura, Katsuyuki
中科院分区：
文献类型：
--
作者：
Sakuma, Hiroshi;Kawamura, Katsuyuki
采用分子动力学模拟方法研究了白云母（001）表面水的结构和动力学行为。直接计算了反映界面结构的X射线反射率分布，并与实验结果进行了比较。直接比较验证了MD模拟的有用性，了解云母-水系统的真实的界面结构。我们观察到五个明显的峰存在于水中的氧的密度分布，这些峰是由于水分子直接吸附在云母上，水合到云母表面上的K+离子，并由于水合K+离子之间的氢键有序。水合的K+离子形成内球复合物，并具有半径为3.6埃和水合数为2.9的明确的第一水合壳层。在离云母表面1 nm以上的位置没有观察到水的粘度的变化。这一特点是在很好的协议与最近的实验研究中，剪切测量进行了表面力装置。粘度增加约1倍。2-3相对于本体水的，在位于离分离的云母表面1 nm内的水处观察到相对于本体水的相对于分离的云母表面的相对于本体水的相对于分离的云母表面的相对于本体水的相对于分离的云母表面的相对于本体水的相对于分离的云母表面的相对于本体水的相对于本体水的相对于分离的云母表面的相对于本体水的相对于分离的云母表面的相对于本体水的相对于本体水的相对于分离的相对于本体水的相对于分离的相对于本体水的相对于分离的相对于分离的云母表面的相对于分离的相对于本体水的相对于本体水的相对于分离的相对于分离的云母表面的相对于本体水的相对于分离的相对于分离的云母表面的相对于分离的相对于本体水的相对于本体(c)2009爱思唯尔有限公司版权所有。
The structure and dynamics of water on muscovite mica (001) surfaces have been investigated by molecular dynamics simulations. X-ray reflectivity profiles highly reflecting the interfacial structure are directly calculated and compared with those of experiments. The direct comparison has validated the usefulness of MD simulations to understand the real interfacial structure of the mica-water system. We observed five distinguished peaks in the density profile of oxygen present in water, and these peaks are attributable to the water molecules directly adsorbed on mica, hydrated to the K+ ions on the mica surface, and ordered due to hydrogen bonds between hydrated K+ ions. The hydrated K+ ions make an inner-sphere complex and have an explicit first hydration shell with a radius of 3.6 angstrom and a hydration number of 2.9. The change of the viscosity of water located above 1 nm apart from the mica surface was not observed. This feature is in good agreement with a recent experimental study in which the shear measurement was conducted using a surface forces apparatus. The increase of the viscosity by a factor of ca. 2-3 relative to that of the bulk water was observed at water located within I nm from the isolated mica surface. (c) 2009 Elsevier Ltd. All rights reserved.