Temperature and Pressure Dependence of the Viscosity of the Ionic Liquid 1-Butyl-3-methylimidazolium Hexafluorophosphate
New measurements have been made for the viscosity of the room-temperature ionic liquid 1-butyl- 3-methylimidazolium hexafluorophosphate ([BMIM]PF6) between (0 and 80) °C with a falling-body viscometer. High-pressure measurements were made at (25, 35, 50, 60, and 70) °C. The overall uncertainty is es...
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Published in | Journal of chemical and engineering data Vol. 50; no. 5; pp. 1777 - 1782 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Chemical Society
01.09.2005
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Subjects | |
Online Access | Get full text |
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Summary: | New measurements have been made for the viscosity of the room-temperature ionic liquid 1-butyl- 3-methylimidazolium hexafluorophosphate ([BMIM]PF6) between (0 and 80) °C with a falling-body viscometer. High-pressure measurements were made at (25, 35, 50, 60, and 70) °C. The overall uncertainty is estimated at ± (2 to 3) %. Atmospheric pressure densities obtained with a vibrating tube densimeter are also reported for temperatures between (0 and 90) °C with an overall uncertainty estimated at ± 0.00005 g·cm-3. The viscosity behavior is qualitatively different from that of molecular liquids, with isotherms being best fitted as functions of the applied pressure rather than as functions of the molar volume. Modified Litovitz and Vogel−Fulcher−Tammann equations have been used to incorporate both the temperature and pressure dependence. Interestingly, the T 0 parameter of the VFT equation appears to be independent of pressure within the state point range of the data, but the Angell strength parameter increases with increasing pressure. |
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Bibliography: | istex:A1F85B134F435D6D50CE3F93EC6E88410EDE8451 ark:/67375/TPS-XJ5KBP86-Q |
ISSN: | 0021-9568 1520-5134 |
DOI: | 10.1021/je050147b |