Structural dynamics and electrical conductivity in ethylene glycol/ hydroxyl ammonium chloride as binary deep eutectic mixtures

Abstract Deep eutectic mixtures (DEMs) are novel materials with amazing properties. Therefore, in this study, ethylene glycol/hydroxyl ammonium chloride, i.e., EG/HACL binary mixtures were prepared with different concentrations (0 wt%, 1.5 wt%, 4 wt%, 6 wt%) starting from neat EG and gradually increasing HACl. Then, their dielectric properties were studied using two dielectric spectrometers with two different frequency ranges (10 −1 Hz–10 7 Hz & 10 6 –3 × 10 9 Hz) and over a wide temperature range (193–323 K) to investigate the possible dynamic relaxation processes and the electrical properties of the prepared mixtures. Fourier-transform infrared spectroscopy (FTIR) was also used to investigate the molecular structure. In addition, it displayed peak-broadening and shifts upon mixing, indicating the formation of hydrogen bonding. Interestingly, as the concentration of HACL increases, the conductivity of binary mixtures increases by about 3 orders of magnitude, particularly for the mixture of 6 wt% HACL due to the increasing number of ions added to the mixture and the increasing mobility. The good electrical properties of this binary mixture make it suitable for energy storage technology.