Phosphonium-Based Ionic Liquids Analogues and Their Physical Properties

Abstract

New ionic liquids analogues, that is, deep eutectic solvents (DESs), have been successfully synthesized. These DESs have been synthesized by the reaction of phosphonium-based salts with different hydrogen bond donors. Many of these DESs have melting temperatures lower than 100 °C. Preliminary laboratory results showed that these DESs can be used in different applications, for example, electrochemical processes, separation of sugars, and so forth. Melting temperature, density, viscosity, pH, conductivity, and dissolved oxygen content of the novel phosphonium-based DESs were measured as a function of temperature. It was found that the type of the salt and hydrogen bond donor and the mole ratio of both compounds have a paramount effect on the studied properties.

Potassium Carbonate as a Salt for Deep Eutectic Solvents

“…In addition, by knowing the temperature effect on viscosity, energy requirements for processing these fluids can be reduced [18] In general, ILs have exponentially decaying viscosity-temperature profiles [19]. Similar behavior has also been reported for some DES systems [5].…”

“…The literature reports very limited experimental ILs viscosity data as function of temperature [5]. Studies conducted on DESs are even very scarce.…”

Theoretical study on the structures and properties of mixtures of urea and choline chloride

“…To differentiate it from ILs, the term deep eutectic solvent (DES) has been adopted. Up to now, many kinds of DESs have been reported, composed mostly of substituted quaternary ammonium salts, e.g., choline chloride, and uncharged hydrogen bond donors such as amine, amide, carboxylic acid, and alcohol [14][15][16]. Meanwhile, these DESs have been applied widely as solvents and reaction mediums in many areas, including electrochemistry [17,18], biochemistry [19][20][21] and material science [22], etc.…”

A review on electrochemical properties of choline chloride based eutectic solvent in mineral processing

“…It should be noted that some DESs, e.g., DES TYPE 3 have a relatively high reduction limit. This allows the use of these DESs in many important electrochemical processes such as leaching and for extraction processes (Kareem, et al, 2010). The electrochemical potential window of the DESs (Ethaline) prepared in this work have been determined using cyclic voltammetry (CV) at a scan rate of 10 mVs -1 illustrated in Fig.…”