New hydrophobic deep eutectic solvent for electrochemical applications

Abstract

Deep eutectic solvents (DESs) are known as cheap and biodegradable solvents which are easier to synthesize than ionic liquids (ILs). In this work, a new hydrophobic DES based on menthol is described. It consisted in a mixture of menthol and acetic acid in which ethanolamine has been added in order to increase the conductivity up to few mS.cm-1. The physicochemical properties as a function of temperature, in the range of 293 to 333 K, of this menthol-based DES have been compared to the ethaline, which is one of the most widely used DES. Cyclic voltammetry has been used to study the electrochemical behavior of an electroactive mediator, the hydroxymethylferrocene (FcMeOH), which is a reversible electrochemical system and its diffusion coefficient, determined in both DESs, is of the same order of magnitude than the one reported for the 1-ethyl-3-methylimidazolium bis(trifluoro-methanesulfonyl)imide (EMIMTFSI), which is the most widely used IL for electrochemical applications. This new class of DES thus provide an eco-friendly alternative for electrochemical applications.

23Na NMR T1 relaxation measurements as a probe for diffusion and dynamics of sodium ions in salt–glycerol mixtures

“…Other methods, such as electrochemical measurements, have also been used to measure diffusion in DESs, showing values of diffusion coefficients similar to those reported for some ionic liquids. 24 Subsequent studies have revealed that inorganic salts can form eutectic mixtures with a variety of amides, polyols and carboxylic acids. These include aluminium chloride, 25 ferric chloride 26 This is the author's peer reviewed, accepted manuscript.…”

Enhancing the electrochemical sensitivity of hydroquinone using a hydrophobic deep eutectic solvent-based carbon paste electrode

“…[18][19][20][21][22] This novel class of solvents has been found to possess some outstanding characteristics [23][24][25][26][27][28][29][30][31][32] which make them highly suitable for applications in different areas, [23][24][25][26][27][28][29][30][31][32] especially in electrochemistry. [33][34][35][36][37][38] DES have emerged as a new class of green solvents which are capable of effectively replacing hazardous organic solvents. 39,40 These new green solvents are less toxic, biodegradable, and non-volatile compared to organic solvents.…”

“…51 Owing to the uniquely interesting properties of DES, many research groups have been conducting comprehensive investigations on these solvents targeted at gaining a better understanding of their properties with a view to applying them in electrochemical studies. 33,35,37 Some studies reported in the literature have employed DES as a medium for nanoparticle electrodeposition 26,52,53 and electropolymerization of conductive polymers, 34,54 and as supporting electrolyte. 35,36 Cariati and Buoro (2019) 55 successfully employed natural deep eutectic solvents (NADES) for the modication of CPE; the authors evaluated the properties of different NADES applied as binders where they used potassium chloride solution to improve the conductivity and reduce the viscosity of NADES.…”

“…33,35,37 Some studies reported in the literature have employed DES as a medium for nanoparticle electrodeposition 26,52,53 and electropolymerization of conductive polymers, 34,54 and as supporting electrolyte. 35,36 Cariati and Buoro (2019) 55 successfully employed natural deep eutectic solvents (NADES) for the modication of CPE; the authors evaluated the properties of different NADES applied as binders where they used potassium chloride solution to improve the conductivity and reduce the viscosity of NADES. The application of the technique helped improve the charge transfer kinetics of the CPE-NADES material.…”

“…18–22 This novel class of solvents has been found to possess some outstanding characteristics 23–32 which make them highly suitable for applications in different areas, 23–32 especially in electrochemistry. 33–38…”