Dielectric Spectroscopy on Choline Chloride based Deep Eutectic Solvents

Deep eutectic solvents (DES) have caught the attention of the scientific community in recent years and are discussed as a promising new class of ionic liquid analogues [1]. Prominent examples are mixtures based on choline chloride (ChCl) with various hydrogen-bound donors like, e.g., glycerol [2]. Although dielectric spectroscopy is an ideal tool to investigate ionic-conductivity mechanisms, until now only a few DES were studies by this method. In this talk, we present dielectric spectroscopy data for three ChCl based DES, covering a broad frequency and temperature range. Our evaluation focuses on the often neglected molecular reorientational dynamics and its correlation with the ionic mobility, as also found in ionic liquids [3].

[1] E. Smith, A. Abbott, and K. Ryder, Chem. Rev. 114, 11060 (2014). [2] A. Faraone, D. V. Wagle, G. A. Baker, E. Novak, M. Ohl, D. Reuter, P. Lunkenheimer, A. Loidl, and E. Mamontov , J. Phys. Chem. B 122, 1261 (2018). [3] P. Sippel, S. Krohns, D. Reuter, P. Lunkenheimer, and A. Loidl, Phys. Rev. E, in press (arXiv:1806.05000).