Surface tension of room temperature ionic liquids measured by dynamic light scattering.
Surface tension of room temperature ionic liquids measured by dynamic light scattering.
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DOI：
10.1063/1.3125182
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发表时间：
2009-05
期刊：
影响因子：
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通讯作者：
R. Osada;T. Hoshino;K. Okada;Y. Ohmasa;M. Yao
中科院分区：
文献类型：
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作者：
R. Osada;T. Hoshino;K. Okada;Y. Ohmasa;M. Yao
用动态光散射技术测定了7种室温离子液体在30~140℃温度范围内的表面张力sigma、表面过剩熵S(Sigma)、表面过剩焓H(Sigma)和粘度eta：1-丁基-3-甲基咪唑双(三氟甲磺酰亚胺)、1-己基-3-甲基咪唑双(三氟甲磺酰基)亚胺、N-甲基-N-丙基哌啶双(三氟甲磺酰亚胺)、N，N，N-三甲基-N-丙基双(三氟甲磺酰亚胺)铵、1-丁基-3-甲基咪唑六氟磷酸盐、1-己基-3-甲基咪唑双(三氟甲磺酰基)亚胺、N，N，N-三甲基-N-丙基双(三氟甲基甲磺酰亚胺)铵盐、1-丁基-3-甲基咪唑六氟磷酸盐、1-己基-3-甲基咪唑双(三氟甲磺酰基)亚胺、N，N，N-三甲基-N-丙基双(三氟甲磺酰亚胺)铵和1-辛基-3-甲基咪唑六氟磷酸盐。我们发现，随着阴离子尺寸和烷基侧链长度的减小，Sigma有规律地增加。而S(Sigma)和ETa则随着阴离子尺寸的减小而增大，随烷基链长度的减小而减小。H(Sigma)似乎随着阴离子尺寸的增大而减小，但与烷基链长没有明显的依赖关系。我们讨论了体和表面的性质，指的是库仑相互作用和范德华相互作用。
Using dynamic light scattering techniques, we obtained the surface tension sigma, surface excess entropy S(sigma), surface excess enthalpy H(sigma), and viscosity eta for the following seven room temperature ionic liquids in a wide temperature range from 30 to around 140 degrees C: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide, N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium hexafluorophosphate, and 1-octyl-3-methyl imidazolium hexafluorophosphate. We have found that sigma increases systematically with decreasing the anion size and the alkyl side chain length. On the other hand, S(sigma) and eta increase with decreasing the anion size but decrease with decreasing the alkyl chain length. H(sigma) seems to decrease with increasing the anion size, but it has no clear dependence on the alkyl chain length. We discuss the bulk and surface properties, referring to the Coulomb interactions and van der Waals interactions.