Volumetric and viscometric properties of aqueous choline chloride + methyldiethanolamine deep eutectic solvents

Amine-based deep eutectic solvents have the advantages of easy preparation, extremely low vapor pressure, stable biodegradation and high CO 2 loading, which has become the most potential CO 2 absorbent. In this work, the amine-based functionalized DES of choline chloride + methyldiethanolamine with different molar ratios were successfully prepared, and the densities and viscosities of DES aqueous solutions were measured from 303.15 K to 333.15 K. The effects of DES composition, water content and temperature on the excess molar volume, partial molar volume, apparent molar volume, limiting partial molar volume and viscosity deviation were investigated. The hydration and intermolecular interaction in DES solution were analyzed. The critical concentration of water in solution was determined under the premise of maintaining DES hydrogen bond network.