433337-23-6Relevant articles and documents
Using a Chromatographic Pseudophase Model to Elucidate the Mechanism of Olefin Separation by Silver(I) Ions in Ionic Liquids
Anderson, Jared L.,Eor, Philip
, p. 13284 - 13292 (2021/10/12)
Silver(I) ions undergo selective olefin complexation and have been utilized in various olefin/paraffin separation techniques such as argentation chromatography and facilitated transport membranes. Ionic liquids (ILs) are solvents known for their low vapor pressure, high thermal stability, low melting points, and ability to promote a favorable solvation environment for silver(I) ion-olefin interactions. To develop highly selective separation systems, a fundamental understanding of analyte partitioning to the stationary phase and the thermodynamic driving forces behind solvation is required. In this study, a chromatographic model treating silver(I) ions as a pseudophase is constructed and employed for the first time to investigate the olefin separation mechanism in silver(I) salt/IL mixtures. Stationary phases containing varying amounts of noncoordinated silver(I) salt ([Ag+][NTf2-]) dissolved in the 1-decyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C10MIM+][NTf2-]) IL are utilized to determine the partition coefficients of various analytes including alkanes, alkenes, alkynes, aromatics, aldehyde, esters, and ketones. As ligand coordination to silver(I) ions is known to lower its olefin complexation capability, this study also examines two different types of coordinated silver(I) ion pseudophases, namely, monocoordinated silver(I) salt ([Ag+(1-decyl-2-methylimidazole, DMIM)][NTf2-]) and dicoordinated silver(I) salt ([Ag+(1-methylimidazole, MIM)(DMIM)][NTf2-]). The extent of olefin partitioning to the coordinated silver(I) ion pseudophases over the carrier gas and IL decreased by up to two orders of magnitude. Values for enthalpy, entropy, and free energy of solvation were determined for the three silver(I) ion-containing systems. Olefin retention was observed to be enthalpically dominated, while ligand coordination to the silver(I) ion pseudophase resulted in variations for both enthalpic and entropic contributions to the free energy of solvation. The developed model can be used to study chemical changes that occur in silver(I) ions over time as well as identify optimal silver(I) salt/IL mixtures that yield high olefin selectivity.
Physicochemical Properties of Long Chain Alkylated Imidazolium Based Chloride and Bis(trifluoromethanesulfonyl)imide Ionic Liquids
Hazrati, Nastaran,Abdouss, Majid,Miran Beigi, Ali Akbar,Pasban, Ali Asghar,Rezaei, Mahmoud
, p. 3084 - 3094 (2017/10/19)
In this research synthesis, purification and characterization of six long-chain imidazolium based ionic liquids (ILs) including C10, C12, and C14 alkyl chain with chloride and NTf2 anions was investigated. All of these studied ILs were characterized using NMR, CHNSO, and DSC, and some impurities such as water, chloride, and metal contents were reported. The temperature dependence of some physicochemical properties such as density, dynamic and kinematic viscosity, refractive index, surface tension, and thermal stability of the synthesized ILs were also studied in the range 283.15 to 363.15 K, and the results were compared with those from the literature. Moreover, using the measured data, the thermal expansion coefficient and molar polarizability of the ILs were calculated. On the other hand the effects of alkyl chain length and anion were explained. The results revealed that although the refractive indices and viscosities increased as alkyl chain length increased, the density and surface tension results were reciprocally decreased. Besides, the results suggest that the synthesized ILs were the best choice as fuel additives.
Liquid-liquid interfacial tension of equilibrated mixtures of ionic liquids and hydrocarbons
Rodriguez, Hector,Arce, Alberto,Soto, Ana
, p. 1519 - 1524 (2012/11/07)
Ionic liquids are possible alternative solvents for the separation of aromatic and aliphatic hydrocarbons by liquid-liquid extraction. Interfacial tension is an important property to consider in the design of liquid-liquid extraction processes. In this work, the liquid-liquid interfacial tension and the mutual solubility at 25 °C have been measured for a series of biphasic, equilibrated mixtures of an ionic liquid and a hydrocarbon. In particular, the ionic liquids 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (with the alkyl substituent being ethyl, hexyl or decyl), 1-ethyl-3- methylimidazolium ethylsulfate, and 1-ethyl-3-methylimidazolium methanesulfonate have been selected, as well as the hydrocarbons benzene, hexane, ethylbenzene, and octane. The selected sets of ionic liquids and hydrocarbons allow the analysis of the influence of a series of effects on the interfacial tension. For example, the interfacial tension decreases with an increase in the length of the alkyl substituent chain of the cation or with an increase of the degree of charge delocalisation in the anion of the ionic liquid. Also, the interfacial tension with the aromatic hydrocarbons is markedly lower than that with the aliphatic hydrocarbons. A smaller effect is caused by variation of the size of the hydrocarbon. Some of the observed trends can be explained from the mutual solubility of the hydrocarbon and the ionic liquid. Science China Press and Springer-Verlag Berlin Heidelberg 2012.
