Molecular dynamics study on water confinement in deep eutectic solvents

The nanoscopic properties of highly diluted water solutions in choline chloride + lactic acid deep eutectic solvent was studied using molecular dynamics simulations as a function of concentration and temperature with the objective of characterize the confinement of water in deep eutectic solvents as a non-regular confinement mechanism. The simulations allowed the analysis of changes in the properties of the deep eutectic solvent in response to the water presence as well as the behaviour of confined water in solvent cavities. The analysis of structural, energetic and dynamic factors provides for the first time the characterization of water confined in these environmentally friendly solvents. The results showed how water can be confined in deep eutectic solvents liquid cages maintaining water individuality with minor changes in the solvent properties, which can be used for tuning water properties for the development of technological applications. (C) 2021 The Authors. Published by Elsevier B.V.