abstract
Mixing ionic liquids is a simple and economical method of exploiting their tunability and allows to use ionic liquids with high melting temperatures for low-temperature applications through the formation of eutectic mixtures. In this study, the phase diagrams of the [C(4)mpy][PF6]-[C(4)mpip][PF6]-[C-4 mpyrr][PF6] ternary system (where [C(4)mpyrr] = 1-butyl-1 -methylpyrrolidinium; [C(4)mpy] = 1-butyl-3-methylpyridinium; [C(4)mpip] = 1-butyl-1-methyl-piperidinium) and all of its unary and binary subsystems were measured and modelled using the Modified Quasichemical Model and the Compound Energy Formalism for the liquid and relevant solid solutions, respectively:the phase diagram determination allowed for density and viscosity measurements over the entire composition range, from temperatures close to the liquidus up to about 110 degrees C. In addition, the thermal and physical properties of the ionic liquid [C(4)mim][PF6] = 1-butyl-3-methylimidazolium) were measured. A new viscosity model was proposed to describe mixtures and was compared to the Grunberg-Nissan mixing law. The proposed model exhibited a better predictive ability for the viscosity data of ternary mixtures compared to the Grunberg-Nissan mixing law with the same number of adjustable parameters. The limits of the proposed viscosity model were analyzed in light of the Gibbs-Adam theory, using viscosity and configurational entropy data for [C(4)mim][PF6]. (C) 2020 Elsevier B.V. All rights reserved.
keywords
SENSITIZED SOLAR-CELLS; QUASI-CHEMICAL MODEL; BINARY-MIXTURES; TEMPERATURE-DEPENDENCE; THERMODYNAMIC PROPERTIES; GLASS-TRANSITION; CHOLINE CHLORIDE; PART II; VISCOSITY; 1-BUTYL-3-METHYLIMIDAZOLIUM
subject category
Chemistry; Physics
authors
Bouarab, AF; Martins, MAR; Stolarska, O; Smiglak, M; Harvey, JP; Coutinho, JAP; Robelin, C
Groups
acknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The modelling part of this project was supported by the Natural Sciences and Engineering Research Council of Canada (Discovery Grant RGPIN 435893-2013). Anya F. Bouarab acknowledges a MITACS Globalink Research Award for her 12-week experimental internship at CICECOAveiro Institute of Materials. Olga Stolarska is grateful to the European Union for the support via grant no. POWR.03.02.00-00-I023/17 cofinanced by the European Union through the European Social Fund under the Operational Program Knowledge Education Development. Marcin Smiglak acknowledges financial support from the National Science Centre (Poland), project SONATA (No. 2011/03/D/ST5/06200).