resumo
This work addresses the effect of different anions in imidazolium-based ionic liquids (ILs) through the formation of aqueous biphasic systems (ABS) using a phosphate buffer solution (KH2PO4/K2HPO4 mixture of salts) aiming at controlling the pH value of the coexisting aqueous phases. Twelve ABS were investigated and the corresponding solubility curves were determined by the cloud point titration method at 298 K. In general, the IL anions aptitude to induce the formation of ABS increases with the decrease of the ability of the ions to form hydration complexes, i.e., with the decrease on the hydrogen-bond basicity of individual fluids. This trend is in close agreement to that observed in ABS with different inorganic salts, showing that the ILs rank is not dependent on the salting-out species used.
palavras-chave
2-PHASE SYSTEMS; MUTUAL SOLUBILITIES; SALTING-OUT; 298.15 K; WATER; EXTRACTION; SEPARATION; EQUILIBRIA; SACCHARIDES; PROTEINS
categoria
Thermodynamics; Chemistry; Engineering
autores
Ventura, SPM; Sousa, SG; Serafim, LS; Lima, AS; Freire, MG; Coutinho, JAP
nossos autores
Luísa Seuanes Serafim
Professor Auxiliar
Mara Guadalupe Freire Martins
Investigador Coordenador
Sónia Patrícia Marques Ventura
Professor AuxiliarGrupos
G4 - Materiais Renováveis e Economia Circular
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
This work was financed by national funding from FCT-Fundacao para a Ciencia e a Tecnologia, through the project PTDC/QUIQUI/121520/2010. The authors also acknowledge FCT for the grant BII of S.G.S. and doctoral and post-doctoral grants SFRH/BD/37830/2007 and SFRH/BPD/41781/2007 of S.P.M.V. and M.G.F., respectively.