Theoretical study of phase transitions in Kr and Ar clathrate hydrates from structure II to structure I under pressure.
Theoretical study of phase transitions in Kr and Ar clathrate hydrates from structure II to structure I under pressure.
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压力下 Kr 和 Ar 笼形水合物从结构 II 到结构 I 的相变的理论研究。
DOI：
10.1063/1.3212965
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
V. Belosludov
中科院分区：
文献类型：
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作者：
O. Subbotin;T. P. Adamova;R. Belosludov;H. Mizuseki;Y. Kawazoe;J. Kudoh;P. Rodger;V. Belosludov
在我们以前的论文中开发的理论扩展到预测的包合物结构的动力学和热力学性质的多重填充的空腔的可能性占客体分子。该方法适用于氩和氪水合物的热力学性质，考虑结构I（SI）和II（SII），其中小笼可以单独占用和大笼的SII可以单独或双重占用。结果表明，笼形水合物的结构主要由两个因素决定：主客体分子间的相互作用和构型熵。结果表明，对于与水分子弱相互作用的客体，如氩或氪，主晶格的自由能是笼形水合物的主要结构决定因素，而熵的贡献则是客体在低压下形成水合物的原因之一.明确考虑吉布斯自由能中的熵贡献，可以确定水合物相的稳定性，并估计P-T平面上从sII到sI的结构转变线。在高压下的氩和氪水合物中的SII和SI之间的结构转变被证明是增加分子间相互作用和大空腔的占有程度的结果。
The theory developed in our earlier papers is extended to predict dynamical and thermodynamic properties of clathrate structures by accounting for the possibility of multiple filling of cavities by guest molecules. The method is applied to the thermodynamic properties of argon and krypton hydrates, considering both structures I (sI) and II (sII), in which the small cages can be singly occupied and large cages of sII can be singly or doubly occupied. It was confirmed that the structure of the clathrate hydrate is determined by two main factors: intermolecular interaction between guest and host molecules and the configurational entropy. It is shown that for guests weakly interacting with water molecules, such as argon or krypton, the free energy of host lattices without the contribution of entropy is the main structure-determining factor for clathrate hydrates, and it is a cause of hydrate sII formation at low pressure with these guests. Explicit account of the entropy contribution in the Gibbs free energy allows one to determine the stability of hydrate phases and to estimate the line of structural transition from sII to sI in P-T plane. The structural transition between sII and sI in argon and krypton hydrates at high pressure is shown to be the consequence of increasing intermolecular interaction and the degree of occupancy of the large cavities.
影响因子：
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作者：
BERENDSEN, HJC;GRIGERA, JR;STRAATSMA, TP
通讯作者：
STRAATSMA, TP
笼形水合物的热力学稳定性IV：双笼占据
DOI：
--
发表时间：
2004
期刊：
J.Chem.Phys. 121
影响因子：
--
作者：
H.Tanaka
通讯作者：
H.Tanaka
氪水合物填充冰的高压拉曼研究
DOI：
--
发表时间：
2011
期刊：
影响因子：
--
作者：
Hirai;H.;篠崎彩子;小松一生;奥地拓生;有馬寛;有馬寛;石尾恵朋;篠崎彩子;平山貴士;寺井達哉;久田旭彦;長壁豊隆;金子耕士;長壁豊隆;寺田典樹;奥地拓生;有馬寛;井上徹;有馬寛;酒井宏紀;吉田将司;Y. Ohno
通讯作者：
Y. Ohno