Thermal Expansivity of Ionic Clathrate Hydrates Including Gaseous Guest Molecules

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• 作者：Kyuchul Shin ; Wonhee Lee ; Minjun Cha ; Dong-Yeun Koh ; Yong Nam Choi ; Heeju Lee ; Bae Soon Son ; Seongsu Lee ; Huen Lee
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：February 10, 2011
• 年：2011
• 卷：115
• 期：5
• 页码：958-963
• 全文大小：833K
• 年卷期：v.115,no.5(February 10, 2011)
• ISSN：1520-5207

文摘

Although thermal expansion is a key factor in relation to the host鈭抔uest interaction of clathrate hydrates, few studies have investigated the thermal behavior of ionic clathrate hydrates. The existence of ionic species in these hydrates creates a unique host鈭抔uest interaction compared to that of nonionic clathrate hydrates. It was revealed that X-ray diffraction cannot be used for research of tetramethylammonium hydroxide clathrate hydrates due to damage of the cations by the X-ray, which results in abnormal thermal expansion of the ionic clathrate hydrates. Hence, in the present work, the thermal expansivities of binary sII Me₄NOD路16D₂O and sI DClO₄路5.5D₂O were measured by neutron powder diffraction (NPD) in order to shed light on their thermal behavior. General correlations for the thermal behaviors of given structures were established and lattice expansions depending on the guests were compared between ionic and nonionic clathrate hydrates. The peculiar change in the thermal expansivity of binary DClO₄路5.5D₂O was also considered in relation to the host鈭抔uest configuration.