Effect of allyl, benzyl, and hydroxyl groups on the CO2 absorption capacity of propanenitrile imidazolium�based ionic liquids incorporating dioctylsulfosuccinate anion

A series of nitrile imidazolium�based ionic liquids (ILs) incorporating benzyl (C2CN Bzim), hydroxyl (C2CN Heim), and allyl (C2CN Ayim) groups with the cation and dioctylsulfosuccinate (DOSS) anion were prepared and characterized using 1H, 13C NMR, and elemental analysis, and the impurities such as moisture and halide content were determined. The CO2 solubility in the prepared ILs was measured using a gravimetric measurement technique at T = 25 to 70 °C and pressures P = 1 to 20 bar. Henry�s law constant and the thermodynamic properties of solvation (enthalpy (�H 0), entropy (�S 0), and Gibbs free energy (�G0)) were calculated from the experimental solubility data. The effect of the aforementioned functional groups on the CO2 solubility was discussed. Graphical Abstract: Figure not available: see fulltext. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.