(Liquid+liquid) equilibrium of aqueous biphasic systems composed of 1-benzyl or 1-hexyl-3-methylimidazolium chloride ionic liquids and inorganic salts

Deive, Francisco J.; Rodríguez, Ana

doi:10.1016/j.jct.2012.05.004

Cited by 17 publications

(7 citation statements)

References 32 publications

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“…The results for four more systems of the same type are presented in our previous work . The binodal data (Tables S2–S9, SI) agree with available literature data ,,− but cover a broader concentration range (Figures S2–S9, SI).…”

Section: Resultssupporting

confidence: 84%

Partitioning of l-Tryptophan in Aqueous Biphasic Systems Containing an Alkylimidazolium Ionic Liquid and a Phosphate Salt

Korchak

Сафонова

Victorov

2021

Ind. Eng. Chem. Res.

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For the development of novel liquid extraction systems, systematic experimental data and methods of predicting liquid−liquid equilibria are required. In this work, we report experimental data for a family of aqueous biphasic systems (ABSs) containing 1-butyl-3-methylimidazolium bromide/chloride, 1hexyl-3-methylimidazolium bromide/chloride, and 1-methyl-3octylimidazolium bromide/chloride in the presence of an inorganic salt (K 2 HPO 4 or K 3 PO 4 ) and assess the predictive capabilities of the ePC-SAFT equation of state in its classical form. The experimental binodal data for eight ABSs have been obtained in a broad concentration range. Although the ePC-SAFT gives a good description of the properties of binary systems, the deviations between experimental and predicted tie lines for the ternary ABSs are significant and the predictions are not quantitative. Improvement in the electrostatic term of the model is required for better performance. We systematically study the partitioning of L-tryptophan, taken as a model solute, and discuss the effect of the alkyl chain length of the imidazolium cation [C n mim] + and the specific effect of the anion of ionic liquids (ILs) (chloride versus bromide). We show that the alkyl chain length of [C n mim] + has almost no effect on the partition coefficients of L-tryptophan (K Trp ) in the ABSs with K 3 PO 4 , while lower K Trp values are found for ILs with the [C 4 mim] + cation for the ABSs with K 2 HPO 4 . A substantial specific effect of the anion of ILs is only observed when the salting-out effect of the inorganic salt is most pronounced, i.e., in the case of the ABSs with K 3 PO 4 . It should be specially mentioned that K Trp values are higher for the ABSs studied in this work in comparison with the available literature data for other IL−salt−water ABSs. This fact implies that the investigated ABSs have high potential for the extraction of biocomponents.

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Section: Resultssupporting

confidence: 84%

Partitioning of l-Tryptophan in Aqueous Biphasic Systems Containing an Alkylimidazolium Ionic Liquid and a Phosphate Salt

Korchak

Сафонова

Victorov

2021

Ind. Eng. Chem. Res.

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“…It has typically been reported that salt anions have the greatest effect on a salt’s ability to salt out or be salted out [ 47 , 48 ], and the results here suggest that some protonation of the IL anions occurs at the higher pH, since the ILs would be considered the kosmotropic (salted out) salts. Prior reports focusing on the protonation of the kosmotropic (salting out) salts (citrate buffer solutions, pH 5–8) indicate that it is easier to salt out imidazolium- or quaternary ammonium-based ILs by increasing pH of the aqueous solution due to the degree of protonation of the citrate ions at different pH [ 49 , 50 ].…”

Section: Resultssupporting

confidence: 58%

Phase Behavior of Aqueous Biphasic Systems with Choline Alkanoate Ionic Liquids and Phosphate Solutions: The Influence of pH

2021

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Aqueous biphasic systems (ABS) composed of the choline alkanoate ionic liquids (ILs) choline acetate [Cho][OAc], choline propanoate [Cho][Pro], choline butyrate [Cho][But], and choline hexanoate [Cho][Hex], mixed with K3PO4 solutions at pH 7.2 and 14.5, were prepared and their phase diagrams were compared. The ability to form ABS with alkaline K3PO4 solutions decreased in the order [Cho][OAc] ≈ [Cho][Pro] > [Cho][But] > [Cho][Hex], while with neutral K3PO4 solutions, [Cho][OAc] could not form an ABS, and the other three ILs performed similarly. All of the biphasic regions of the ABS decreased with the increase in pH. 1H-NMR data indicated anion exchange between phases in ABS at neutral pH. The ABS at neutral pH were evaluated to extract the triazine herbicides simazine, cyanazine, and atrazine, and the ABS formed by [Cho][Pro] and the pH 7.2 K3PO4 solution has shown extraction recoveries higher than 90%.

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“…Ternary phase diagrams of the studied {IL + salt + H 2 O} system at T = 296 K and atmospheric pressure ( p = 0.1 MPa): blue ◇, [beim][Br]/K 3 PO 4 ; blue ◆, [beim][Br]/K 2 HPO 4 ; purple ◀, [hmim][Cl]/K 2 HPO 4 ; purple ◁, [hmim][Cl]/K 2 HPO 4 ; green ▶, [bmim][Cl]/K 2 HPO 4 .…”

Section: Resultsmentioning

confidence: 99%

“…Literature data for [hmim][Cl] is compared with those obtained in this work in Figure . In the article of Deive et al [hmim][Cl] was synthesized according to the procedure described in the literature elsewhere . In our experiments, we used [hmim][Cl] purchased from Iolitec GmbH without any pretreatment.…”

Section: Resultsmentioning

confidence: 99%

Liquid–Liquid Equilibria in Aqueous 1-Alkyl-3-methylimidazolium- and 1-Butyl-3-ethylimidazolium-Based Ionic Liquids

et al. 2015

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In this work, novel phase diagrams for aqueous solutions of 1-alkyl-3-methylimidazolium-and 1-butyl-3-ethylimidazolium-based ILs combined with phosphate-based salts, namely, K 3 PO 4 or K 2 HPO 4 , are reported and discussed. To correlate the binodal data, the Merchuk equation is applied. The tie lines and tie-line lengths are also presented. The anion influence on the ability to form aqueous biphasic system (ABS) is investigated for the IL with the same1-butyl-3-methylimidazolium cation, [bmim] + , and various anions, for example, salicylate, [SAL] − ; trifluoromethanesulfonate, [TFS] − ; dicyanamide, [DCA] − ; and chloride, [Cl] − . The order of studied anions to form ABS is [TFS]The effect of alkyl chain length on imidazolium ion on liquid− liquid equilibrium is discussed in terms of increasing ionic liquid hydrophobicity and poorer affinity for water. It is shown that 1-hexyl-3-methylimidazolium chloride ionic liquid has a better ability to form ABS comparing to ionic liquid with butyl chain and the same anion. Newly synthesized ionic-liquidcontaining ethyl group 1-butyl-3-ethylimidazolium bromide was also investigated, showing the influence of both ethyl group and bromide anion on the ability of ABS formation. ■ INTRODUCTIONIonic liquids (ILs) are the salts with melting point lower than 373.15 K showing low toxicity, biodegradability, a negligible vapor pressure, high conductivity and thermal stability. 1 Such unique properties make them alternative solvents for toxic volatile organic compounds. Due to their tunable physical and chemical properties, they are called designed solvents and can be applied in many industrial and technological processes, as well in analytical separation techniques. 2−8 Recently, the newest generation of ILs with targeted biological properties containing biologically active components extends the sphere of their use in pharmacy, medicine, and agriculture as potential drugs. 9−17 Liquid−liquid extraction based on ionic liquids and waterstructuring salts as aqueous biphasic systems have been reported for the first time in 2003. 18 These systems have been successfully used to separate drugs, 19−22 proteins, 23 dyes, 24 and pesticides. 25 Liquid−liquid equilibrium (LLE) data at different temperatures and compositions are essential for the optimization of extraction process using ABS. For this purpose, water-soluble hydrophilic ionic liquids can be used as extracting solvent, as they induce formation of aqueous biphasic systems with suitable kosmotropic agents forming a new type of partitioning systems. 18,26,27 Such ABS with the right proportions of ionic liquid and kosmotropic salt can be used as an alternative extraction medium to conventional systems of either liquid−liquid or liquid−solid type.Contrary to previous reports that hydrophilic ionic liquids are structure breakers or "chaotropes", 28−31 kosmotropic properties of many imidazolium-based ILs containing different anions such as halide, dicyanamide or salicylate were reported. 32−34 It was described that these ILs strongly in...

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(Liquid+liquid) equilibrium of aqueous biphasic systems composed of 1-benzyl or 1-hexyl-3-methylimidazolium chloride ionic liquids and inorganic salts

Cited by 17 publications

References 32 publications

Partitioning of l-Tryptophan in Aqueous Biphasic Systems Containing an Alkylimidazolium Ionic Liquid and a Phosphate Salt

Partitioning of l-Tryptophan in Aqueous Biphasic Systems Containing an Alkylimidazolium Ionic Liquid and a Phosphate Salt

Phase Behavior of Aqueous Biphasic Systems with Choline Alkanoate Ionic Liquids and Phosphate Solutions: The Influence of pH

Liquid–Liquid Equilibria in Aqueous 1-Alkyl-3-methylimidazolium- and 1-Butyl-3-ethylimidazolium-Based Ionic Liquids

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