authors |
Passos, H; Dinis, TBV; Capela, EV; Quental, MV; Gomes, J; Resende, J; Madeira, PP; Freire, MG; Coutinho, JAP |
nationality |
International |
journal |
PHYSICAL CHEMISTRY CHEMICAL PHYSICS |
keywords |
SOLVATOCHROMIC COMPARISON METHOD; SOLVATION ENERGY RELATIONSHIP; HYDROGEN-BOND ACIDITY; 2-PHASE SYSTEMS; SOLVENT PROPERTIES; RELATIVE HYDROPHOBICITY; METHYLENE GROUP; EXTENDED SCALE; PEG-SALT; EXTRACTION |
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, G(CH2), and on the Kamlet-Taft parameters - dipolarity/polarizability (*), hydrogen-bonding donor acidity () and hydrogen-bonding acceptor basicity () - 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. |
publisher |
ROYAL SOC CHEMISTRY |
issn |
1463-9076 |
year published |
2018 |
volume |
20 |
issue |
13 |
beginning page |
8411 |
ending page |
8422 |
digital object identifier (doi) |
10.1039/c8cp00383a |
web of science category |
Chemistry, Physical; Physics, Atomic, Molecular & Chemical |
subject category |
Chemistry; Physics |
unique article identifier |
WOS:000428779700003
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ciceco authors
impact metrics
journal analysis (jcr 2019):
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journal impact factor |
3.43 |
5 year journal impact factor |
3.735 |
category normalized journal impact factor percentile |
69.267 |
dimensions (citation analysis):
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altmetrics (social interaction):
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