Department of Physical Chemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza Str.11/12, 80-233 Gdansk, Poland.
Department of Analytical Chemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza Str.11/12, 80-233 Gdansk, Poland.
Molecules. 2020 Feb 1;25(3):634. doi: 10.3390/molecules25030634.
In recent years, many papers describing ionic liquids (IL) as promising solvents in separation techniques have been published. The conscious choice of appropriate ionic liquid as absorption media in effective extraction of selected types of analytes requires deeper understanding of the analyte-IL interactions. Therefore, intensive research is conducted to determine the values of activity coefficient at infinite dilution, which allows us to characterize the nature of these interactions. Based on the inverse gas chromatography retention data, activity coefficients at infinite dilution γ 13 ∞ of 48 different organic compounds in the ionic liquids -ethyl--methylmorpholinium bis(trifluoromethanesulfonyl)imide [CCMor][TFSI] and -octyl--methylmorpholinium bis(trifluoromethanesulfonyl)imide [CCMor][TFSI] were determined. The measurements covered a broad range of volatile organic compounds, including -alkanes, -alkenes, -alkynes, alcohols, aldehydes, ketones, aromatic compounds and common polar solvents, representing different types of interactions. Activity coefficients at infinite dilution were measured in the temperature range from 313.15 to 363.15 K. The excess partial molar enthalpies and entropies at infinite dilution were determined. Selectivity at infinite dilution was also calculated for exemplary separation processes in the hexane/benzene system. The obtained results were analyzed and compared with literature data for ionic liquids containing the same anion [TFSI]¯ and different cations. The study results indicate that some potential applications of the investigated ionic liquids in separation problems exist.
近年来，有许多描述离子液体（IL）作为分离技术中很有前途的溶剂的论文发表。有意识地选择合适的离子液体作为吸收介质，以有效地萃取选定类型的分析物，需要更深入地了解分析物与 IL 的相互作用。因此，进行了大量的研究来确定无限稀释时的活度系数，这使我们能够表征这些相互作用的性质。基于反气相色谱保留数据，测定了 48 种不同有机化合物在离子液体 -乙基--甲基吗啉双（三氟甲烷磺酰基）亚胺 [CCMor][TFSI] 和 -辛基--甲基吗啉双（三氟甲烷磺酰基）亚胺 [CCMor][TFSI]中的无限稀释活度系数γ13∞。测量涵盖了广泛的挥发性有机化合物，包括 -烷烃、-烯烃、-炔烃、醇、醛、酮、芳香族化合物和常见的极性溶剂，代表了不同类型的相互作用。在 313.15 至 363.15 K 的温度范围内测量了无限稀释活度系数。还确定了无限稀释时的超额偏摩尔焓和熵。还针对在己烷/苯体系中的示例性分离过程计算了无限稀释时的选择性。对获得的结果进行了分析，并与含有相同阴离子[TFSI]-和不同阳离子的离子液体的文献数据进行了比较。研究结果表明，所研究的离子液体在分离问题上有一些潜在的应用。
