Structure and Electrical Conductivity of Urea–Choline Chloride Deep Eutectic Solvent
摘要
Fourier transform infrared spectroscopy (FTIR) technique was employed for structural analysis of choline chloride–urea (ChCl–2Urea) deep eutectic solvent (DES). The FTIR spectra was an overlap of structures of urea and ChCl. The bands formed at 3444 and 3347 cm−1 was broad indicating the formation of hydrogenHydrogen bonds between urea and ChCl. The electrochemical impedance spectroscopy (EIS) tool was successfully used to obtain the electrical conductivitiesElectrical conductivity (κ) of ChCl–2Urea at different temperaturesTemperature (343–383 K). The electrical conductivityElectrical conductivity showed temperatureTemperature dependency with an increase in κ with increase in temperatureTemperature. The κ increased from 6.57 mS cm−1 at 343 K to 28.92 mS cm−1 at 383 K. Such enhancement is attributed to the weak attractive forces between the ions at higher temperaturesTemperature and decreased viscosityViscosity leading to less resistance to ions movement. The measured electrical conductivityElectrical conductivity data for ChCl–2Urea DES follows the Arrhenius law from which activation energyActivation energy (E) of conduction is determined as 4.83 ± 0.20 kJ mol−1.