Experimental and computational study of soft matter: structural and reactivity characterization of ionic liquids and deep eutectic solvent

The search of novel alternative to traditional solvents has interested the scientific community for many years. During the last years many systems were proposed: among these noteworthy are Ionic Liquids (ILs) and Deep Eutectic Solvents (DES). The idea behind these novel liquids is to enhance and improve the eco-compatibility of traditional traditional solvents by using these materials as viable, more environmentally friendly substitutes for conventional solvents or molecular liquids. The peculiar physical and chemical properties exhibited by these solvents (as low melting point, low volatility, large thermal and electrochemical window stability) are originated by the extraordinary coordination occurring in the liquid phase: hydrogen bonding, for instances, plays a crucial role on the stabilization of liquid phase in both ILs and DESs. In this thesis, with the aim of understanding the innovative properties exhibited by DESs and ILs, we investigated by a combined experimental and computational approach, the structure of many DESs. We performed thermal analysis (DSC and TGA) and vibrational spectroscopy (FIR, MIR and, when necessary, Raman spectroscopies). The bulk phase, for some systems, was also studied by Wide-angle X-Ray scattering (WAXS). To better understand the interactions and conduct an accurate interpretation of the experimental data, all systems were modelled by computational approaches, using DFT and classical MD simulations. We also investigated on the interactions of ILs onto graphene surface. The chemiadsorption was deeply investigated by computational approach: DFT calculation and MD simulation provided a good description of the interaction between cation and anion and between ILs and N-doped graphene surface. The studied ionic liquids presented an high capability to reacts with CO2, making them a promising candidate as a CO2 scrubber. With the aim of characterize the thermodynamic of the chemiadsorption reaction we investigated by DFT on the reaction mechanisms, characterizing each critical point, both for bulk and adsorbed ionic liquids.