Insight into the Interactions That Control the Phase Behaviour of New Aqueous Biphasic Systems Composed of Polyethylene Glycol Polymers and Ionic Liquids
authors Freire, MG; Pereira, JFB; Francisco, M; Rodriguez, H; Rebelo, LPN; Rogers, RD; Coutinho, JAP
nationality International
journal CHEMISTRY-A EUROPEAN JOURNAL
author keywords biphasic systems; ionic liquids; phase diagrams; polyethylene glycol; salting-in; -out
keywords HUMAN-SERUM ALBUMIN; 2-PHASE SYSTEMS; PHYSICOCHEMICAL PROPERTIES; MUTUAL SOLUBILITIES; REACTION MEDIA; TEMPERATURE; EXTRACTION; PARTITION; IMIDAZOLIUM; WATER
abstract New polyethylene glycol (PEG)/ionic liquid aqueous biphasic systems (ABS) are presented. Distinct pairs of PEG polymers and ionic liquids can induce phase separation in aqueous media when dissolved at appropriate concentrations. Phase diagrams have been determined for a large array of systems at 298, 308 and 323 K. A comparison of the binodal curves allowed the analysis of the tunable structural features of the ionic liquid (i.e., anionic nature, cationic core, cationic alkyl side chain length and functionalisation, and number of alkyl substituents in the cation) and the influence of the molecular weight of the PEG polymer on the ability of these solutes to induce an ABS. It was observed that contrary to typical ABS based on ionic liquids and inorganic salts, in which the phase behaviour is dominated by the formation of the hydration complexes of the ions, the interactions between the PEG polymers and ionic liquids control the phase demixing in the polymer-type ABS studied herein. It is shown that both the ionic liquids and PEG polymers can act as the salting-out species; that is, it is an occurrence that is dependent on the structural features of the ionic liquid. For the first time, PEG/ionic liquid ABS are reported and insight into the major interactions that govern the polymer/ionic liquid phase behaviour in aqueous media are provided. The use of two different nonvolatile and tunable species (i.e., ionic liquids and PEG polymers) to form ABS allows the polarities of the phases to be tailored. Hence, the development of environmentally friendly separation processes that make use of these novel systems is envisaged.
publisher WILEY-BLACKWELL
issn 0947-6539
year published 2012
volume 18
issue 6
beginning page 1831
ending page 1839
digital object identifier (doi) 10.1002/chem.201101780
web of science category Chemistry, Multidisciplinary
subject category Chemistry
unique article identifier WOS:000299626400035
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 5.160
5 year journal impact factor 4.950
category normalized journal impact factor percentile 78.655
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg