Calorimetric Studies and Structural Aspects of Ionic Liquids in Designing Sorption Materials for Thermal Energy Storage

Abstract

The thermal properties of a series of twenty‐four ionic liquids (ILs) have been determined by isothermal titration calorimetry (ITC) with the aim of simulating processes involving water sorption. For eleven water‐free ILs, the molecular structures have been determined by X‐ray crystallography in the solid state, which have been used to derive the molecular volumes of the ionic components of the ILs. Moreover, the structures reveal a high prevalence of hydrogen bonding in these compounds. A relationship between the molecular volumes and the experimentally determined energies of dilution could be established. The highest energies of dilution observed in this series were obtained for the acetate‐based ILs, which underlines their potential as working fluids in sorption‐based thermal energy storage systems.

Predicting Melting Points of Biofriendly Choline-Based Ionic Liquids with Molecular Dynamics

“…The harmful TFSI anion was included for comparison purpose and because choline TFSI is relatively well studied in the literature. To the best of our knowledge, the crystal structure is known only for choline acetate, choline acesulfamate, choline saccharinate and choline TFSI among the studied ILs [21][22][23][24]. Thus, for each IL, we generated a solid phase using Coulombic potential wells inspired by the PSCP method [19,20].…”

Analyzing the solution behavior of hygroscopic Imidazolium and Choline based ILs for optimizing liquid sorption media

“…The high purity of these procedure is evidenced by the crystal structures of the compounds 3, 7, 8, 12, 13, 19, 25-30. 4 …”

“…Therefore, a calorimetric analysis offers an insight in the interaction between cation, anion and water. 4 In combination with other investigation, we hope to obtain a simulation of the sorption process. …”

Investigations of structure property relationships of highly hygroscopic Imidazolium and Choline based ILs for the prediction of thermodynamic trends

“…The high purity of these procedure is evidenced by the crystal structures of the compounds 3, 7, 8, 12, 13, 19, 25-30. 7 …”

“…The interaction between cation and anion can be investigated by analyzing the crystal structure. 7 In our work, we synthesized various 1,3-functionalized imidazolium and choline based Ils for the use as drying agent in sorption systems. Here especially substances with organic anion such as acetate, lactate and formate were quiet interesting because they expected, among other beneficial properties, a low melting point and a strongly pronounced hygroscopic behavior.…”