Structural and Dynamical Properties of a Deep Eutectic Solvent Confined Inside a Slit Pore

Abstract

We performed molecular dynamics (MD) simulations to study the structure and dynamics of the deep eutectic solvent (DES) choline iodide-glycerol (CI.G) at a molar ratio of 1:3, inside slitlike titania [rutile (110)] and graphitic nanopores of width H = 5.2 and 2.5 nm, and at a temperature T = 333 K. DESs share many of the remarkable properties of ionic liquids (ILs) while being more inexpensive; furthermore, and in addition to their fundamental scientific interest, the systems modeled here are relevant to dye-sensitized solar cells and gas separations. Our results show that glycerol can form stable hydrogen bonds with the oxygen atoms in the rutile walls, which account for ∼86% of the total number of hydrogen bonds involving DES species (choline, iodide, and glycerol) in the first layers (near the rutile walls), and for ∼24% of the total hydrogen bonds observed for the DES inside a rutile pore of width H = 5.2 nm. As a result, in these systems, the rutile walls are coated by glycerol layers that are almost...