abstract
Ionic liquids (ILs) with improved hydrogen-bonding acceptor abilities such as acetate-based compounds, have shown great potential for CO2 capture and biomass dissolution. In this context, the knowledge of the thermophysical properties of acetate-based fluids is essential for the design and scale-up of related processes. However, at this stage, acetate-based ILs are still poorly characterized. In this work, four thermophysical properties, specifically, density, viscosity, refractive index, and surface tension, were determined for five acetate-based ILs. Both protic and aprotic ILs were investigated, namely, N,N-dimethyl-N-ethylammonium acetate, 1-ethylimidazolium acetate, 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-1-methylpyrrolidinium acetate. From the temperature dependence of the measured properties, additional properties, such as the isobaric thermal expansion coefficient, the surface entropy and enthalpy, and the critical temperature, were further estimated.
keywords
ALKYL CHAIN-LENGTH; SURFACE TENSIONS; 1-BUTYL-3-METHYLIMIDAZOLIUM ACETATE; THERMODYNAMIC PROPERTIES; PHYSICOCHEMICAL PROPERTIES; TRANSPORT-PROPERTIES; SOLVENT PROPERTIES; TEMPERATURE; IMIDAZOLIUM; ANION
subject category
Thermodynamics; Chemistry; Engineering
authors
Almeida, HFD; Passos, H; Lopes-da-Silva, JA; Fernandes, AM; Freire, MG; Coutinho, JAP
our authors
Helena Isabel Sousa Passos
Junior Researcher
Mara Guadalupe Freire Martins
Coordinating ResearcherGroups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
Projects
BIIPP - Biorefinaria Integrada na Indústria da Pasta e Papel (BIIPP)
Sweetening of natural gas using ionic liquids (PTDC/EQU-FTT/102166/2008)
acknowledgements
This work was funded by QREN SI-I&DT Project No. 11551 from UE/FEDER through COMPETE program. The authors also acknowledge FCT-Fundacao para a Ciencia e a Tecnologia for the projects Pest-C/CTM/LA0011/2011 and PTDC/EQU-FTT/102166/2008 and for the postdoctoral grant (SFRH/BPD/41781/2007) of M.G.F.