abstract
A series of novel analogues of glycine-betaine ionic liquids (AGB-ILs), viz. 1-(4-ethoxy-4-oxobutyl)-1-methylpyrrolidin-1-ium, N,N,N-tri(n-butyl)(4-ethoxy-4-oxobutyl)-1-phosphonium and N,N,N-tri-alkyl(4-ethoxy-4-oxobutyl)-1-aminium cations with ethyl, n-propyl and n-butyl alkyl chains, combined with the bromide anion, have been synthesized and characterized. Their synthesis and characterization by spectroscopic methods and elemental analysis is here reported. These ILs were further characterized in what concerns their thermal properties and ecotoxicity against Allvibrio fischeri, and compared with degrees the commercial tetra(n-butyl)ammonium and tetra(n-butyl)phosphonium bromide. The novel AGB-ILs described in this work have low melting points, below 100 degrees C, display high degradation temperatures (180-310 degrees C), and low toxicity as shown by being harmless or practically harmless towards the marine bacteria Allvibrio fischeri. Finally, the ability of the synthesized AGB-ILs to form aqueous biphasic systems with potassium citrate/citric acid (at pH 7) was evaluated, and the respective ternary phase diagrams were determined. It is shown that the increase of the cation alkyl chain length facilitates the creation of ABS, and that phosphonium-based ILs present a slightly better separation performance in presence of aqueous solutions of the citrate-based salt. (C) 2019 Elsevier B.V. All rights reserved.
keywords
ENHANCED EXTRACTION; CATION; PHOSPHONIUM; TOXICITY; PRETREATMENT; SOLVENTS; RECOVERY; REMOVAL; BIOMASS; STRESS
subject category
Thermodynamics; Chemistry; Engineering
authors
Pereira, MM; Pedro, SN; Gomes, J; Sintra, TE; Ventura, SPM; Coutinho, JAP; Freire, MG; Mohamadou, A
our authors
Mara Guadalupe Freire Martins
Coordinating Researcher
Matheus M. Pereira
Researcher
Sónia Isabel Neto Pedro
PhD Student
Sónia Patrícia Marques Ventura
Assistant Professor
Tânia Ereira Sintra
Post-Doc FellowshipGroups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
G6 - Virtual Materials and Artificial Intelligence
Projects
Igy Technology: A Purication Platform using Ionic-Liquid-Based Aqueous Biphasic Systems (IGYPURTECH)
acknowledgements
This work was developed within the scope of the project FCT Ref. UlD/CTM/50011/2019, financed by national funds through the FCT/MCTES. M. M. Pereira acknowledges the PhD grant (2740-13-3) and financial support from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior Capes and the Short Term Scientific Mission grant COST-STSM-ECOST-STSM-CM1206-011015-066583. M. G. Freire acknowledges the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC Grant 337753. We acknowledge D. Harakat for the ESI-MS measurements.