Charge transport and structural dynamics in deep eutectic mixtures (DEMs)*

Charge transport and structural dynamics in choline chloride and glycerol mixtures were studied by broadband dielectric spectroscopy (BDS), dynamic mechanical spectroscopy (DMS), and differential scanning calorimetry (DSC). Slow sub-α relaxations are observed with BDS and DMS spectra. With decreasing choline chloride concentration, the sub-α dielectric relaxation, that is coupled to ion diffusion becomes much slower, while the slower mechanical relaxation is unaffected. This unexpected result is discussed within the framework of recent theories of ion transport and sub-α dynamics in small-molecule liquids.