- The Viscosity and Density of Ionic Liquid + Tetraglyme Mixtures and the Effect of Tetraglyme on CO2 Solubility
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We show that the addition of tetraglyme (TG), which is a low viscosity liquid with relatively low vapor pressure, is effective in reducing the viscosity of ionic liquids (ILs). In particular, we measure the viscosities of mixtures of 18 ionic liquids with tetraglyme at temperatures between 278.15 and 323.15 K, with a focus on mixtures that are primarily ionic liquid. Thirteen of the ionic liquids contain aprotic heterocyclic anions (AHA ILs) paired with tetra-alkylphosphonium and imidazolium cations, which we have developed for cofluid vapor compression refrigeration and postcombustion CO2 capture applications. Three bis(trifluoromethylsulfonyl)amide ([Tf2N]-) ionic liquids are included for comparison, as well as trihexyltetradecylphosphonium acetate and trihexyltetradecylphosphonium dicyanamide ([P66614][acetate] and [P66614][DCA]). In addition, we present the densities of trihexyltetradecylphosphonium 1,2,3-triazolide ([P66614][3-Triz]) + tetraglyme mixtures at temperatures between 283.15 and 353.15 K. Finally, we show that the solubility of CO2 in mixtures of [P66614][3-Triz] + 30 mol % tetraglyme and trihexyltetradecylphosphonium 1,2,4-triazolide ([P66614][4-Triz]) + 30 mol % tetraglyme at 313.15, 333.5, and 353.6 K and pressures to 34 bar can be represented reasonably well by a mole fraction weighted sum of the solubilities (on a mole ratio basis) in the two pure components. (Figure Presented).
- Fillion, Joseph J.,Bennett, Joshua Edward,Brennecke, Joan F.
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- Experimental Densities and Calculated Fractional Free Volumes of Ionic Liquids with Tri- and Tetra-substituted Imidazolium Cations
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Although it has been estimated that there are at least 1 million ionic liquids (ILs) that are accessible using commercially available starting materials, a great portion of the ILs that have been experimentally synthesized, characterized, and studied in a variety of applications are built around the relatively simple 1-n-alkyl-3-methylimidazolium ([Cnmim]) cation motif. Yet, there is no fundamental limitation or reason as to why tri- or tetra-functionalized imidazolium cations have received far less attention. Scant physical property data exist for just a few trifunctionalized imidazolium-based ILs and there is virtually no data on tetra-functionalized ILs. Thus, there are a broad experimental spaces on the "map" of ILs that are largely unexplored. We have sought to make an initial expedition into these "uncharted waters" and have synthesized imidazolium-based ILs with one more functional group(s) at the C(2), C(4), and/or C(5) positions of the imidazolium ring (as well as N(1) and N(3)). This manuscript reports the synthesis and experimental densities of these tri- and tetra-functionalized ILs as well as calculated densities and fractional free volumes from COSMOTherm. To the best of our knowledge, this is the first report of any detailed experimental measurements or computational studies relating to ILs with substitutions at the C(4) and C(5) positions.
- Yue, Shuwen,Roveda, John D.,Mittenthal, Max S.,Shannon, Matthew S.,Bara, Jason E.
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p. 2522 - 2532
(2018/07/25)
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- Ionic liquids promote PCR amplification of DNA
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A bicyclic imidazolium ionic liquid (4d), [b-4C-im][Br], was found to be highly effective not only for promoting PCR of GC-rich DNA by minimizing non-specific amplification, but also for facilitating PCR of normal-GC DNA under mild conditions.
- Shi, Yugang,Liu, Yen-Liang,Lai, Peng-Yeh,Tseng, Ming-Chung,Tseng, Min-Jen,Li, Yudong,Chu, Yen-Ho
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supporting information; experimental part
p. 5325 - 5327
(2012/06/30)
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- Organic redox couples and organic counter electrode for efficient organic dye-sensitized solar cells
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A series of organic thiolate/disulfide redox couples have been synthesized and have been studied systematically in dye-sensitized solar cells (DSCs) on the basis of an organic dye (TH305). Photophysical, photoelectrochemical, and photovoltaic measurements were performed in order to get insights into the effects of different redox couples on the performance of DSCs. The polymeric, organic poly(3,4-ethylenedioxythiophene) (PEDOT) material has also been introduced as counter electrode in this kind of noniodine-containing DSCs showing a promising conversion efficiency of 6.0% under AM 1.5G, 100 mW·cm-2 light illumination. Detailed studies using electrochemical impedance spectroscopy and linear-sweep voltammetry reveal that the reduction of disulfide species is more efficient on the PEDOT counter electrode surface than on the commonly used platinized conducting glass electrode. Both pure and solvated ionic-liquid electrolytes based on a thiolate anion have been studied in the DSCs. The pure and solvated ionic-liquid-based electrolytes containing an organic redox couple render efficiencies of 3.4% and 1.2% under 10 mW·cm-2 light illumination, respectively.
- Tian, Haining,Yu, Ze,Hagfeldt, Anders,Kloo, Lars,Sun, Licheng
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supporting information; experimental part
p. 9413 - 9422
(2011/08/05)
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- High-pressure phase behavior of carbon dioxide with imidazolium-based ionic liquids
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Previously we have shown that supercritical carbon dioxide can be used to extract organics from ionic liquids (ILs). Subsequently, ionic liquids/carbon dioxide biphasic solutions have been used for a variety of homogeneously catalyzed reactions. Therefore, an understanding of the phase behavior of carbon dioxide with ionic liquids is needed to design extraction and reaction processes necessary for these applications. We present measurements of the solubility of carbon dioxide in 10 different imidazolium-based ionic liquids at 25, 40, and 60?°C and pressures to 150 bar. As expected, the solubility increases with increasing pressure and decreases with increasing temperature for all the ILs investigated. To investigate the influence of the anion, seven of the ILs studied have 1-butyl-3-methylimidazolium ([bmim]) as the cation. The anions are dicyanamide ([DCA]), nitrate ([NO3]), tetrafluoroborate ([BF4]), hexafluorophosphate ([PF6]), trifuoromethanesulfonate ([TfO]), bis(trifluoromethylsulfonyl)imide ([Tf 2N]), and tris(trifluoromethylsulfonyl)methide ([methide]). The other ILs considered in the study, chosen to investigate the influence of varying number and length of alkyl chains on the cation, include 1-hexyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim][Tf2N]), 2,3-dimethyl-1-hexylimidazolium bis(trifluoromethylsulfonyl)imide ([hmmim][Tf2N]), and 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([omim][Tf2N]). Results show that the solubility of carbon dioxide is strongly dependent on the choice of anion. In particular, CO2 solubility is greater in ILs with anions, such as [Tf2N] and [methide], which contain fluoroalkyl groups. Also, we observe that an increase in the alkyl chain length on the cation increases the CO2 solubility marginally.
- Aki, Sudhir N. V. K.,Mellein, Berlyn R.,Saurer, Eric M.,Brennecke, Joan F.
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p. 20355 - 20365
(2008/01/27)
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