Liquid Structure and Transport Properties of the Deep Eutectic Solvent Ethaline
Yong Zhang, Derrick Poe, Luke Heroux, Henry Squire, Brian Doherty, Zhuoran Long, Mark Dadmun, Burcu Gurkan, Mark E. Tuckerman, Edward J. Maginn
Abstract
A range of techniques including physical property measurements, neutron scattering experiments, ab initio molecular dynamics and classical molecular dynamics simulations 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 environment 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.