422. Thermodynamic Properties, Activity Coefficients at Infinite Dilution and Cosmo-SAC Modelling of Deep Eutectic Solvents at Different Temperatures

Ncomeka Mgxadeni,  Dr. Bakusele Kabane,  Prof. Indra Bahadur,  Prof. Márcio L. L. Paredes,  Prof. Rafael de P. Soares,  Dr. Shailendra Kumar Singh,  Prof. Faruq Mohammad and  Prof. Ahmed Abdullah Soleiman, ChemistrySelect (2023), DOI: 10.1002/slct.202204192

A deep understanding of the solute- deep eutectic solvent (DESs) interactions is required for an appropriate selection of DESs as absorption media in the extraction of binary mixtures. As a result, these studies are done to evaluate the values of the activity coefficients at infinite dilution, allowing us to define and understand the nature of these intermolecular interactions comprising DES mixtures with volatile organic solvents at different temperatures using gas liquid chromatography technique to determine the for 34 solutes in DESs [zinc chloride+acetic or phosphoric acid] prepared at 1 : 2 molar ratio for the temperature range (313.15–353.15) K. The thermal stability of the prepared DESs was determined by a thermogravimetric analyser. Excess thermodynamic parameters [partial molar excess enthalpies and Gibbs free energies ] were derived from the data. The selectivity and capacity values for the industrial separations were calculated and compared with the literature values of other DESs, ionic liquids, and sulfolane to assess the suitability of the investigated DESs for possible applications as extracting solvents. The selectivity and capacity values are high and therefore, [zinc chloride+acetic or phosphoric acid] can be used as a potential solvent to replace the currently used conventional solvents in the separation of the selected azeotropes. COSMO-SAC predictions were qualitatively in very good agreement with the experimental data.