Lorenzo GUAZZELLI1, Andrea MEZZETTA1, Stefano BECHERINI1, Joao AFONSO2, Isabel MARRUCHO2
1University of Pisa, Department of Pharmacy, Pisa, Italy
2Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Lisboa, Portugal
Ionic liquids (ILs) and deep eutectic solvents (DESs) are two classes of media which have the potential to drive the ecological transition in several different research areas. Although different entities, ILs and DESs share some attractive features, the most astonishing being their designer solvent nature. This denomination is often used to describe the possibility to tailor the properties of these materials for a specific application by changing the pairing ions (for ILs), and the components and molar ratio (for DESs). Recently, we started to look into the relationship between ILs and DESs,  highlighting similarities, clear differences and complementarity in some aspects. In this context, an interesting and yet not completely exploited option is the possibility to convert ILs into DESs by adding a suitable additive. This way, even ILs characterized by high melting point can be converted into media suitable for application requiring temperatures close to ambient temperature. Herein, a further step forward in this research area is presented, with a particular focus on a model natural material that can be used as a source of both ILs and DESs (Figure 1).
In depth analysis of thermal behavior and stability, of the rheological properties and of other relevant physico-chemical properties during the transition from ILs to DESs have been a matter of investigation. Furthermore, comparative evaluation of the two preparation protocols, their environmental impact and cost has been performed. Overall, this work aims at highlighting the possibility to tailor ILs properties ex-post (after their preparation) by turning them into suitable DESs, expanding at the same time their field of applications.
 J. Afonso, A. Mezzetta, I. Marrucho, L. Guazzelli Green Chemistry, 2022, accepted for publication.