Task-Specific Ionic Liquid for Solubilizing Metal Oxides

Abstract

Protonated betaine bis(trifluoromethylsulfonyl)imide is an ionic liquid with the ability to dissolve large quantities of metal oxides. This metal-solubilizing power is selective. Soluble are oxides of the trivalent rare earths, uranium(VI) oxide, zinc(II) oxide, cadmium(II) oxide, mercury(II) oxide, nickel(II) oxide, copper(II) oxide, palladium(II) oxide, lead(II) oxide, manganese(II) oxide, and silver(I) oxide. Insoluble or very poorly soluble are iron(III), manganese(IV), and cobalt oxides, as well as aluminum oxide and silicon dioxide. The metals can be stripped from the ionic liquid by treatment of the ionic liquid with an acidic aqueous solution. After transfer of the metal ions to the aqueous phase, the ionic liquid can be recycled for reuse. Betainium bis(trifluoromethylsulfonyl)imide forms one phase with water at high temperatures, whereas phase separation occurs below 55.5 degrees C (temperature switch behavior). The mixtures of the ionic liquid with water also show a pH-dependent phase behavior: two phases occur at low pH, whereas one phase is present under neutral or alkaline conditions. The structures, the energetics, and the charge distribution of the betaine cation and the bis(trifluoromethylsulfonyl)imide anion, as well as the cation-anion pairs, were studied by density functional theory calculations.

Using UCST Ionic Liquid as a Draw Solute in Forward Osmosis to Treat High-Salinity Water

“…Water purified by a Milli-Q (Milli Pore) system was [Hbet][Tf2N] shows a tendency to crystallize rather than to form a glass). 36 The NMR results of the crystal are as follows The water flux in a typical FO process was first tested with DI water as the feed and concentrated IL (3.2 M) as the draw solution. Both IL and DI water were first warmed to the target temperature before being poured to the feed and draw side of the FO instrument, respectively, and then the entire instrument was placed in a hot water bath to maintain the target temperature.…”

“…The IL used here is protonated betaine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]). 36 The structure is shown in Chart 1. Contrary to the LCST-type IL, the UCST-type IL is immiscible with water at room temperature.…”

The Soft Material Obtained from an Europium (III)-Containing Ionic Liquid

“…Only limited papers about the higher concentration of the lanthanide ions in ionic liquid have been reported. 12,15,[17][18][19] Incorporating lanthanide ions as an anion into ionic liquids is an effective way to increase the concentration of lanthanides. 13,14,16 An alternative approach to increase the solubility of metal salts is to use task-specific ionic liquids (TSIL) bearing a complexing moiety.…”

Room-Temperature Zwitterionic Ionic Liquids

“…They have been used as Bronsted acidic catalysts [10], for desulfurization of fuels [11], for metal oxides solubilization [12] or as liquid crystals [13].…”