A new aqueous biphasic system containing polypropylene glycol and a water‐miscible ionic liquid

Abstract

In this work, we proposed a novel aqueous biphasic system (ABS) composed of polypropylene glycol P400 (PPG P400) and hydrophilic ionic liquids (IL), 1-alkyl-3-methylimidazolium bromide (alkyl = ethyl or butyl), forming an upper polymer-rich phase and a lower IL-rich phase at ambient temperature. This new ABS can present interesting characteristics shared by ILs and polymers such as low volatility, good solvation ability, tunable physical properties, and high design capacity for achieving task-specific phase components to enhance the partitioning of target species. Ternary phase diagram of the novel ABS formed by PPG 400 and [C(2) mim]Br in water was measured at T = 298.15 K. Factors affecting the binodal curves such as the cation side alkyl chain length and the temperature were also evaluated. The results were successfully interpreted in terms of the kosmotropic/chaotropic nature of ILs. Furthermore, the phase behavior of the PPG-[C(2) mim]Br ABS is described by the NRTL model. Finally, the extraction potential of the proposed ABS was evaluated through its application to the extraction of the essential amino acids such as L-tryptophan and L-tyrosine. The partition coefficients here obtained demonstrated the fine potential of the proposed ABS for biomolecules separation.

Ionic-Liquid-Mediated Extraction and Separation Processes for Bioactive Compounds: Past, Present, and Future Trends

“…With a goal of designing more environmentally benign and biocompatible ABS, Zafarani-Moattar and Hamzehzadeh 198 employed PPG 400 and hydrophilic ILs, [C n C 1 im]Br ( n = 2, 4), for the extraction of l -Trp and l -Tyr. Curiously, in polymer-IL-based ABS, l -Tyr displays a preferential partition toward the polymer-rich phase while l -Trp kept the preference for the IL-rich phase.…”

“…This difference was attributed to the lack of one pyrrole ring in l -Tyr when compared to l -Trp. 198 However, the salt replacement by the polymer in IL-based ABS resulted in significantly lower partition coefficient values, which highlights the need to strike a balance between the properties of the phase-forming components, the nature of the target compounds, and the processing conditions, in order to achieve the highest efficiency. Even so, this opposite partition of the two amino acids may be seen as a promising trend when envisaging the development of fractionation platforms of amino acids from complex and raw mixtures.…”

Aqueous two-phase system (ATPS): an overview and advances in its applications

“…One-polymer ATPSs have also been reported, which utilize only one polymer for the formation of ATPS in water [20]. PEGs of different molecular weights are widely used polymers in ATPS due to their low toxicity, low price and low volatile nature [21]. Table 1 shows different types of ATPS with representative examples.…”

“…Phase separation in ATPS is affected by different factors like, concentration and molecular weight (MW) of polymer, concentration and composition of salt [21, 23]. The presence of salt also influences phase behavior which also bring changes according to the type and concentration.…”

Aqueous biphasic systems composed of ionic liquids and sodium carbonate as enhanced routes for the extraction of tetracycline

“…A recent overview of the developments in ABS has evidenced that various components besides the conventional polymer/polymer and polymer/salt combinations are also capable of forming ABS, namely ionic liquids (ILs). In fact, IL‐based ABS can be formed by the addition of aqueous solutions of inorganic/organic salts, amino acids, carbohydrates, or polymers …”