Liquid Structure and Transport Properties of the Deep Eutectic Solvent Ethaline.

A range of techniques including physical property measurements, neutron scatter- ing experiments, ab initio molecular dynamics and classical molecular dynamics simu- lations are used to probe the structural, thermodynamic, and transport properties of a deep eutectic solvent comprised of a 1:2 molar ratio of choline chloride and ethylene glycol. This mixture, known as Ethaline, has many desirable properties for use in a range of applications and therefore understanding its liquid structure and transport properties is of interest. Simulation results are able to capture experimental densities, diffusivities, viscosities, and structure factors extremely well. The solvation environ- ment is dynamic and dominated by different hydrogen bonding interactions. Dynamic heterogenities resulting from hydrogen bonding interactions are quantified. Rotational dynamics of molecular dipole moments of choline and ethylene glycol are computed and found to exhibit a fast and slow mode.