1
|
Ahrenberg M, Beck M, Neise C, Keßler O, Kragl U, Verevkin SP, Schick C. Vapor pressure of ionic liquids at low temperatures from AC-chip-calorimetry. Phys Chem Chem Phys 2018; 18:21381-90. [PMID: 27425628 DOI: 10.1039/c6cp01948j] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The very low vapor pressure of ionic liquids is challenging to measure. At elevated temperatures the liquids might start to decompose, and at relatively low temperatures the vapor pressure becomes too low to be measured by conventional methods. In this work we developed a highly sensitive method for mass loss determination at temperatures starting from 350 K. This technique is based on an alternating current calorimeter equipped with a chip sensor that consists of a free-standing SiNx-membrane (thickness <1 μm) and a measuring area with lateral dimensions of the order of 1 mm. A small droplet (diameter ca. 600 μm) of an ionic liquid is vaporized isothermally from the chip sensor in a vacuum-chamber. The surface-to-volume-ratio of such a droplet is large and the relative mass loss due to evaporation is therefore easy to monitor by the changing heat capacity (J K(-1)) of the remaining liquid. The vapor pressure is determined from the measured mass loss rates using the Langmuir equation. The method was successfully tested for the determination of the vapor pressure and the vaporization enthalpy of an archetypical ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][NTf2]). The data set created in this way in an extremely broad temperature range from 358 K to 780 K has allowed the estimation of the boiling temperature of [EMIm][NTf2]. The value (1120 ± 50) K should be considered as the first reliable boiling point of the archetypical ionic liquid obtained from experimental vapor pressures measured in the most possible close proximity to the normal boiling temperature.
Collapse
Affiliation(s)
- Mathias Ahrenberg
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18059 Rostock, Germany.
| | - Martin Beck
- Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Albert-Einstein-Str. 2, 18059 Rostock, Germany
| | - Christin Neise
- Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Olaf Keßler
- Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Albert-Einstein-Str. 2, 18059 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany
| | - Udo Kragl
- Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany
| | - Sergey P Verevkin
- Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany
| | - Christoph Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18059 Rostock, Germany. and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany
| |
Collapse
|
2
|
Synthesis, characterization, and CO2 separation performance of polyether sulfone/[EMIM][Tf2N] ionic liquid-polymeric membranes (ILPMs). J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2017.05.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
3
|
Neise C, Rautenberg C, Bentrup U, Beck M, Ahrenberg M, Schick C, Keßler O, Kragl U. Stability studies of ionic liquid [EMIm][NTf2] under short-term thermal exposure. RSC Adv 2016. [DOI: 10.1039/c6ra06129j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mass spectrometer coupled TG analysis was used to identify decomposition products of thermally highly stressed ionic liquids.
Collapse
Affiliation(s)
- Christin Neise
- Institute of Chemistry
- University of Rostock
- 18059 Rostock
- Germany
| | | | - Ursula Bentrup
- Leibniz Institute for Catalysis (LIKAT Rostock)
- 18059 Rostock
- Germany
| | - Martin Beck
- Faculty of Mechanical Engineering and Marine Technology
- Chair of Materials Science
- University of Rostock
- 18059 Rostock
- Germany
| | | | | | - Olaf Keßler
- Faculty of Mechanical Engineering and Marine Technology
- Chair of Materials Science
- University of Rostock
- 18059 Rostock
- Germany
| | - Udo Kragl
- Institute of Chemistry
- University of Rostock
- 18059 Rostock
- Germany
| |
Collapse
|