Comparative Study of Physical Properties and CO₂ Solubility of Ammonium and Sulfonium Ionic Liquids in Mixture with Glutaronitrile

Abstract

In this work, we present a comparative study of physical properties and CO2 solubility of two ionic liquids (ILs), protic trimethylammonium bis­[(trifluoromethyl)­sulfonyl]­imide and aprotic trimethylsulfonium bis­[(trifluoromethyl) sulfonyl]­imide in mixture with glutaronitrile (GLN). The effect of temperature on density and viscosity of mixtures was studied and discussed in terms of intra- and intermolecular interactions. Applying Glasser’s theory, standard molar entropy, S 0, and the crystal energy, U POT, of the IL/GLN mixtures were estimated, showing a positive contribution of ILs to these quantities. This positive contribution to the entropy variation by the addition of an IL is because of the fact that it destroys GLN–GLN interactions, replacing them with new cation–GLN and anion–GLN interactions. The deconstructing effect of S111 is greater because there are no strong S111–GLN interactions, unlike the ammonium cation which can establish H-bonds with CN groups. The CO2 solubilities in both (IL/GLN) mixtures expressed by CO2 molar fractions, x CO2 , or the Henry constant K H/MPa showed that the [S111]­[TFSI]/GLN solubilizes more CO2 than the [HN111]­[TFSI]/GLN throughout the temperature range. The solubility of CO2 is sensitive to the cation nature and temperature. The sulfonium cation promotes CO2 solubility because it is less cluttered than the ammonium cation unlike HN111, which is the hydrogen-binding seat (NH–GLN) with GLN. Finally, the thermodynamic parameters such as the standard enthalpy Δdiss H 0, the free enthalpy Δdiss G 0, and the entropy Δdiss S 0 of CO2 dissolution were calculated. They showed that the dissolution of CO2 did not depend on the molecular organization (small variation in entropy) but that it is linked to the intermolecular interactions in the IL/GLN mixture, as shown by the difference in Δmix H.

Non‐Flammable Sodium Asymmetric Imide Salt‐Based Deep Eutectic Solvent for Supercapacitor Applications

“…After the floating process, the I D /I G ratio increased to 1.33, leading to a greater number and/or size of sp 2 clusters. The Ragone plots for the SCs comprising the two eutectic mixtures are on par with SC comprising organic [4,20,37] media and superior to SCs with aqueous [38–41] and DES media [24,26,27] …”

“…The Ragone plots for the SCs comprising the two eutectic mixtures are on par with SC comprising organic [4,20,37] media and superior to SCs with aqueous [38][39][40][41] and DES media. [24,26,27]…”

“…The tabulated volumetric coefficients of expansion (α) lie between those of organic solvents (i. e., 4 × 10 À 4 < α < 7 × 10 À 4 ; K À 1 ) [19,[21][22][23] and ionic liquids (i. e., 8 × 10 À 4 < α < 10 × 10 À 4 ; K À 1 ), [24,25] suggestive of systems containing self-associated molecules. [26] Generally, the DESs molar volume values range from 72 to 264 cm 3 mol À 1 . [27] The calculated molecular volumes here vary between 77 and cm 3 , in the lowest range of the DESs category.…”

Characterization of Manganese Acetate Hydrate Solutions and Their Potential Use for Energy Storage Applications

“…The α values (−3.63 to −5.31×10 −4 K −1 , Table 2) are typical of systems containing self‐associated molecules such as ionic liquids [35] and are higher than the one of liquid water viz. −2.0×10 −4 K −1 [36] .…”

“…where α is the coefficient of thermal expansion that reflects the restructuring ability of the solution under thermal agitation. The α values (À 3.63 to À 5.31×10 À 4 K À 1 , Table 2) are typical of systems containing self-associated molecules such as ionic liquids [35] and are higher than the one of liquid water viz. À 2.0×10 À 4 K À 1 .…”