Transformation of hydrogen bond network during CO2 clathrate hydrate dissociation
Transformation of hydrogen bond network during CO2 clathrate hydrate dissociation
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DOI：
10.1016/j.apsusc.2019.143644
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发表时间：
2020-01-01
影响因子：
6.7
通讯作者：
Kawazoe, Yoshiyuki
中科院分区：
文献类型：
--
作者：
Gets, Kirill;Belosludov, Vladimir;Kawazoe, Yoshiyuki
本文研究了不同空腔占比下二氧化碳CS-I水合物固液一级相变的动力学过程，以了解氢键网络的框架和每个水分子的局部结构。这包括在接近熔点的温度下随时间变化的短期顺序，以及与六边形冰结构的比较。利用分子动力学方法，得到了系统的内能随加热时间的变化规律。固体的内能在275-300 K范围内的跳跃表明相变。通过对无> 3.2埃分离分子之间的氧-氧径向分布和氢-氧-氧相互取向角的研究，确定了所有分子的氢键配位数和氢键总数，并显示了所有分子的短程顺序的瞬时（< 1 ns）重组。对相邻水分子对的结构分析表明，熔化后氢键数减少了10-15%，而所有分子形成一个单一的远程氢键网络。对氢键网络的分析表明，固-液相变过程中氢键相互作用能发生了微小变化。
The kinetic process of the solid-liquid first-order phase transition of carbon dioxide CS-I hydrates with various cavity occupation ratios has been investigated in order to understand the framework of the H-bond network and the local structure of each water molecule. This includes the time dependent change in short-range order at temperatures close to the melting point and comparison with the hexagonal ice structure. Using the molecular dynamics method, dependencies of the internal energy of the studied systems on the time of heating were found. Jumps in the internal energy of solids in the range at 275-300 K indicate a phase transition. The study of the oxygen-oxygen radial distribution and hydrogen-oxygen-oxygen mutual orientation angles between molecules detached at no > 3.2 angstrom led to the determination of the H-bond coordination number for all molecules and the total number of H-bonds and showed instantaneous (< 1 ns) reorganization of the short-range order of all molecules. Structural analysis of neighbor water molecule pairs showed similar to 10-15% decrease in the H-bond number after melting whereas all molecules form a single long-range H-bond network. Analysis of the H-bond network showed minor changes in the H-bond interaction energy at the solid-liquid phase transition.