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http://hdl.handle.net/10773/29011
Title: | Mechanisms ruling the partition of solutes in ionic-liquid-based aqueous biphasic systems: the multiple effects of ionic liquids |
Author: | Passos, Helena Dinis, Teresa B. V. Capela, Emanuel V. Quental, Maria V. Gomes, Joana Resende, Judite Madeira, Pedro P. Freire, Mara G. Coutinho, João A. P. |
Issue Date: | 7-Apr-2018 |
Publisher: | Royal Society of Chemistry |
Abstract: | In the past decade, the remarkable potential of ionic-liquid-based aqueous biphasic systems (IL-based ABSs) to extract and purify a large range of valued-added biocompounds has been demonstrated. However, the translation of lab-scale experiments to an industrial scale has been precluded by a poor understanding of the molecular-level mechanisms ruling the separation or partition of target compounds between the coexisting phases. To overcome this limitation, we carried out a systematic evaluation of specific interactions, induced by ILs and several salts used as phase-forming components, and their impact on the partition of several solutes in IL-based ABSs. To this end, the physicochemical characterization of ABSs composed of imidazolium-based ILs, three salts (Na2SO4, K2CO3 and K3C6H5O7) and water was performed. The ability of the coexisting phases to participate in different solute-solvent interactions (where "solvent" corresponds to each ABS phase) was estimated based on the Gibbs free energy of transfer of a methylene group between the phases in equilibrium, ΔG(CH2), and on the Kamlet-Taft parameters - dipolarity/polarizability (π*), hydrogen-bonding donor acidity (α) and hydrogen-bonding acceptor basicity (β) - of the coexisting phases. Relationships between the partition coefficients, the phase properties expressed as Kamlet-Taft parameters and COSMO-RS descriptors were established, highlighting the ability of ILs to establish specific interactions with given solutes. The assembled results clearly support the idea that the partition of solutes in IL-based ABSs is due to multiple effects resulting from both global solute-solvent and specific solute-IL interactions. Solute-IL specific interactions are often dominant in IL-based ABSs, explaining the higher partition coefficients, extraction efficiencies and selectivities observed with these systems when compared to more traditional ones majorly composed of polymers. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/29011 |
DOI: | 10.1039/c8cp00383a |
ISSN: | 1463-9076 |
Appears in Collections: | CICECO - Artigos DQ - Artigos |
Files in This Item:
File | Description | Size | Format | |
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final manuscript.pdf | 2.75 MB | Adobe PDF |
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