Studies on the intermolecular interaction of ChCl-MEA-PZ deep eutectic solvent aqueous solution through volumetric and viscometric methods

To address the issue of global warming, it is a viable approach to capture carbon dioxide from flue gas by using a novel absorbent -deep eutectic solvent (DES) aqueous solution. The investigation of intermolecular interactions for DES (choline chloride (ChCl) - monoethanolamine (MEA) - piperazine (PZ)) - H2O system holds significant importance. The density and viscosity data of the DES aqueous solution were utilized to calculate various volumetric and viscosity properties. The thermal expansion coefficient, excess molar volume, activation energy for viscous flow, viscosity deviation and excess Gibbs energy of activation were utilized to investigate the intermolecular interactions in DES aqueous solution. The hydrogen bond network structure between ChCl-MEAPZ DES molecules and water molecules was analyzed. The impact of water content on the structure of DES could be categorized into three regions: DES structural integrity region, DES structural partial retention region, and DES structural complete destruction region.