Designing the thermal behaviour of aqueous biphasic systems composed of ammonium-based zwitterions

authors	Ferreira, AM; Passos, H; Okafuji, A; Freire, MG; Coutinho, JAP; Ohno, H
nationality	International
journal	GREEN CHEMISTRY
keywords	TEMPERATURE IONIC LIQUIDS; SATURATED WATER-CONTENT; METAL-OXIDES; EXTRACTION; PHASE; MIXTURES; PARTITION; PROTEINS; RECOVERY; SOLVENT
abstract	The ability of water-soluble ammonium-based zwitterions (ZIs) to form aqueous biphasic systems (ABS) in the presence of aqueous solutions of salts is disclosed here. These systems are thermoreversible at temperatures close to room temperature and further allow the design of their thermal behavior, from an upper critical solution temperature (UCST) to a lower critical solution temperature (LCST), by increasing the ZI alkyl chain length. The investigated thermoreversible ABS are more versatile than typical liquidliquid systems, and can be applied in a wide range of temperatures and compositions envisaging a target separation process. An example is given regarding their ability to selectively separate mixtures of aromatic and aliphatic amino acids in a single-step.
publisher	ROYAL SOC CHEMISTRY
issn	1463-9262
year published	2017
volume	19
issue	17
beginning page	4012
ending page	4016
digital object identifier (doi)	10.1039/c7gc02262j
web of science category	Chemistry, Multidisciplinary; GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY
subject category	Chemistry; Science & Technology - Other Topics
unique article identifier	WOS:000408588100006