Liquid–Liquid Equilibria in Aqueous Mixtures of Alkylmethylimidazolium Glutamate with Potassium Carbonate and Some Physicochemical Properties of Aqueous [C_nmim][Glu] (n = 4, 6, 8) Solutions

Abstract

Aqueous biphasic systems containing ionic liquids (ILs) attract rather high attention; in particular their application in liquid–liquid extraction is very attractive due to the specificity of the systems and great possibilities in the modification of IL chemical structures. In the present work, a series of amino acid ionic liquids (AAILs) based on the 1-alkyl-3-methylimidazolium cation and l-glutamic acid anion [C n mim]­[Glu] (n = 4, 6, 8) were synthesized. Densities, refractive indices, and specific electrical conductivities of aqueous solutions of these AAILs in the concentration range 0–70 wt % (for [C4mim]­[Glu] solutions up to 87 wt %) were measured at temperature 298.15 K and ambient pressure 0.1 MPa. The liquid–liquid equilibria for ternary solutions [C n mim]­[Glu] + salt (K2CO3) + water at 298.15 K were under study. In aqueous solutions of [C8mim]­[Glu] micellization is observed, whereas [C4mim]­[Glu] and [C6mim]­[Glu] in aqueous solutions form small ordinary aggregates. The critical micellar concentration for [C8mim]­[Glu] aqueous solutions at 298.15 K was estimated from the experimental data on the concentration dependence of the specific electrical conductivities of the solutions.

Evaluation of Ionic Liquids Based on Amino Acid Anions for Use in Liquid‐junction Free Reference Electrodes

“…Analytical grade inorganic electrolytes were from Reachim, Russia. Amino acid‐based ionic liquids were synthesized in house from 1‐butyl‐3‐methylimidazolium chloride as described in . The structures of the investigated ILs are shown in Figure .…”

Separation of amino acids and β-blockers enantiomers by capillary electrophoresis with 1-butyl-3-methylimidazolium L-prolinate [C4MIm][L-Pro] as a chiral selector

“…Синтез аминокислотной ионной жидкости [C 4 MIm][L-Glu] выполняли согласно [26]. Первоначально получали гидроксид 1-бутил-3-метилимидазолия [C 4 MIm]ОН способом, описанным выше, а затем при 0 °C и при перемешивании добавляли по каплям его водный раствор к водному раствору L-глутаминовой кислоты.…”

Ionic Liquids-Based Aqueous Biphasic Systems with Citrate Biodegradable Salts

“…The research on IL-based ABS has increased in the last years, − but the majority of the salts used on ABS are inorganic salts; the application of salts more environmentally friendly, such as citrates or tartrates, have seldom been investigated. ,,,− ,− …”