Some DESs also offer certain green features, the greenness of which is notoriously enhanced when combined with water. Interestingly, despite the macroscopic homogeneous appearance of this sort of aqueous binary mixtures, both NMR spectroscopic studies and molecular dynamics simulations have revealed the occurrence of certain dynamic heterogeneity at a microscopic molecular level. Our group is currently using the combination of Brillouin, NMR and SANS spectroscopies with the aim of getting further insights of the local structure rearrangements occurring in liquid mixtures of H-bonded co-solvents composed of DES and water. This is by no means a trivial issue given that combines fundamental aspects with applied ones.

For instance, we have demonstrated how the transition from the collapsed to the expanded state of elastin like recombinamers in their collapsed state is suppressed in neat DES but it can be recovered upon addition of water − above 50 wt %. This is an example of how the use aqueous DES dilutions as a novel green medium may open interesting perspectives in biotechnological processes.

Moreover, we have also demonstrated the capability of aqueous solutions of DESs for the preparation of porous carbons via spinodal decomposition processes and subsequent carbonization so that the resulting structure just depends on the DES dilution.

Predicting the suitability of aqueous solutions of deep eutectic solvents for preparation of co-continuous porous carbons via spinodal decomposition processes
E . Posada, N. López-Salas, D. Carriazo, M. A. Muñoz-Márquez, C. O. Ania, R. J. Jiménez-Riobóo, M. C. Gutiérrez, M. L. Ferrer*, F. del Monte*
Carbon. 2017, 123, 536-547