The thermodynamic stability of clathrate hydrate. III. Accommodation of nonspherical propane and ethane molecules
The thermodynamic stability of clathrate hydrate. III. Accommodation of nonspherical propane and ethane molecules
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笼形水合物的热力学稳定性。
DOI：
10.1063/1.467832
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发表时间：
1994
影响因子：
4.4
通讯作者：
Hideki Tanaka
中科院分区：
文献类型：
--
作者：
Hideki Tanaka
本文通过考察笼占据自由能的各种分量，研究了笼形水合物包裹非球形分子的热力学稳定性。在本研究中，我们通过扩展广义货车德瓦尔斯和普拉特夫理论[Tanaka和Kiyohara，J.Chem.Phys.98，4086和8110（1993）]，发展了一种处理非球形客体分子笼形水合物的方法。研究了非球形丙烷和乙烷分子转动运动的势能面。与客体分子的非球形性质相关联的自由能被评价为从参考系统的扰动囚禁球形客人。客体分子和主体分子的振动自由能分为谐波和非谐波贡献。后一项是必不可少的自由能的受阻旋转的客人进行评估和热力学性质被发现是在良好的协议与测量值。动力学行为…
The thermodynamic stability of clathrate hydrates encaging nonspherical molecules has been investigated by examining the various components of the free energy of cage occupancy. In the present study, we develop a method to treat clathrate hydrates of nonspherical guest molecules by extending a generalized van der Waals and Platteeuw theory [Tanaka and Kiyohara, J. Chem. Phys. 98, 4086 and 8110 (1993)]. The potential energy surfaces for the rotational motions of nonspherical propane and ethane molecules are examined. The free energy associated with the nonspherical nature of the guest molecules is evaluated as a perturbation from the reference system encaging spherical guests. The vibrational free energy of both guest and host molecules is divided into harmonic and anharmonic contributions. The latter term that is essential in the free energy of the hindered rotation for the guests is evaluated and thermodynamic properties are found to be in good agreement with the measured values. The dynamical behaviors ...