(78f) Deep Eutectic Solvents in Confinement: Structure, Dynamics and CO2 Solubility

Molecular dynamics (MD) simulations were performed to study systems of deep eutectic solvents (DESs) inside slit-like nanopores. DESs share many of the physical and chemical properties of room temperature ionic liquids (ILs) while being considerably cheaper and (mostly) nontoxic. Here we first studied the structure and dynamics of common DESs inside slit-like titania and graphitic nanopores. Our results show that the properties of the DES can be significantly affected by the pore width and the chemical composition of the pore walls. In particular, when the species forming the DES can form hydrogen bonds with atoms in the pore walls, we observe important inhomogeneities in local composition, significant changes in liquid structure and very slow dynamics in the confined DES when compared to its bulk counterpart. In the second part of our study, we considered systems of CO₂ and common DESs inside slit-like nanopores. This part of our work was motivated by previous studies exploring the use of bulk DESs in CO₂ capture, as well as by recent reports of the â??oversolubilityâ? phenomenon, where it has been observed that gas molecules exhibit increased solubility in solvents that are confined within a nanoporous material. Here we performed molecular simulations of systems of CO₂ and DESs in the bulk and inside slit graphitic nanopores at different conditions; detailed comparisons of the properties of these systems will be presented and discussed.