Thermodynamic Effect on Viscosity and Density of a Mixture of 4-Cyano-4′-pentylbiphenyl (5CB) with Dilute Dimethyl Phthalate (DMP)
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- Shimada Ryoko
- Department of Mathematical and Physical Sciences, Japan Women’s University
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- Watanabe Hiroshi
- Institute for Chemical Research, Kyoto University
Bibliographic Information
- Other Title
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- Thermodynamic Effect on Viscosity and Density of a Mixture of 4-Cyano-4'-pentylbiphenyl (5CB) with Dilute Dimethyl Phthalate (DMP)
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Abstract
<p>Density ρ and viscosity η were examined for 4-cyano-4′-pentylbiphenyl (5CB) and its mixture with dilute dimethyl phthalate (DMP; wDMP = 3.1 wt%). The mixture was in an isotropic 1-phase state at temperatures T > TIN* (<tt>≅</tt> 27 ºC), and exhibited the phase separation into the isotropic and nematic phases at TIN*. Pure 5CB exhibited the (well known) first-order isotropic-to-nematic transition characterized by discontinuous changes of ρ and η at TIN (<tt>≅</tt> 35.0 ºC), whereas no discontinuous changes were observed for the mixture at TIN* because only a small amount of the nematic phase was created at TIN*. The discontinuity was expected for the local density and viscosity in the nematic phase at TIN* and, in this sense, no essential difference was noted for that phase in the 5CB and DMP/5CB systems. Nevertheless, a characteristic difference was found in the isotropic 1-phase state. These systems commonly exhibited simple asymptotic behavior at sufficiently high T, linear thermal expansion of the specific volume 1/ρ and Eyring/Andrade-type T dependence of the kinematic viscosity, ν = η/ρ. Positive deviation from these asymptotes was noted for both systems on cooling toward respective transition temperatures, TIN and TIN*, but in a considerably wide range of T (up to TIN*+10K or more) for the DMP/5CB mixture whereas only in a close vicinity of TIN (within a few K) for pure 5CB. This difference is related to the concentration fluctuation (due to the soft, osmotic interaction of molecules) emerging only in the mixture.</p>
Journal
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- Nihon Reoroji Gakkaishi
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Nihon Reoroji Gakkaishi 48 (4), 199-206, 2020-09-15
The Society of Rheology, Japan
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Details 詳細情報について
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- CRID
- 1390567901492890880
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- NII Article ID
- 130007926347
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- NII Book ID
- AN00198812
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- ISSN
- 21864586
- 03871533
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- NDL BIB ID
- 030666194
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- Text Lang
- en
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- Data Source
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- JaLC
- NDL
- Crossref
- CiNii Articles
- KAKEN
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- Abstract License Flag
- Disallowed