A density functional theory based tight-binding study on the water effect on nanostructuring of choline chloride plus ethylene glycol deep eutectic solvent

The effect of water on the properties of an archetypical type III deep eutectic solvent [choline chloride : ethyleneglycol (1:2)] is analyzed using ab initio molecular dynamics simulations in the 0 to 60 wt. % water content range. The properties of the mixed fluids are studied considering nanostructuring, intermolecular forces (hydrogen bonding), the energy of interactions, dynamic properties, and domain analysis. The reported results confirm that the change in the properties of the studied deep eutectic solvent is largely dependent on the amount of water. The competing effect of water molecules for the available hydrogen bonding sites determines the evolution of the properties upon water sorption. The main structural features of the considered deep eutectic were maintained even for large water contents; thus, its hydrophilicity could be used for tuning fluid physicochemical properties. Published under an exclusive license by AIP Publishing.

Automated summary

This study analyzed the effect of water on the properties of an archetypical type III deep eutectic solvent using ab initio molecular dynamics simulations. The results showed that the properties of the deep eutectic solvent were significantly influenced by the amount of water, and the competition of water molecules for available hydrogen bonding sites played a crucial role in the evolution of the properties. Moreover, the main structural features of the deep eutectic solvent were maintained even at high water contents, suggesting that its hydrophilicity could be used to tune the physicochemical properties of the fluid.