Orientador(es)
Resumo(s)
The present work describes an experimental study and the
thermodynamic modeling for the solid−liquid phase diagram of an ionic liquid
quaternary system constituted by hexafluorophosphate ([PF6]−) as the common
anion and by 1-methyl-3-propylimidazolium ([C3mim]+), 1-methyl-1-propylpyrrolidinium
([C3mpyrr]+), 1-methyl-3-propylpyridinium ([C3mpy]+), or 1-methyl-
1-propylpiperidinium ([C3mpip]+) as the cations. The Modified Quasichemical
Model was used to model the liquid solution, and the Compound Energy
Formalism was used for the relevant solid solutions. The liquidus projections of
the four ternary subsystems (1) [C3mim][PF6]−[C3mpip][PF6]−[C3mpyrr]-
[PF6], (2) [C3mpy][PF6]−[C3mpip][PF6]−[C3mpyrr][PF6], (3) [C3mpip]-
[PF6]−[C3mpy][PF6]−[C3mim][PF6], and (4) [C3mpyrr][PF6]−[C3mpy]-
[PF6]−[C3mim][PF6] were predicted using a standard symmetric (for systems 3
and 4) or asymmetric (for systems 1 and 2) interpolation method. In order to test
the accuracy of the thermodynamic model, two isoplethal sections were experimentally measured in each of the four ternary
systems using differential scanning calorimetry. Overall, agreement was very satisfactory, not requiring fitting of any ternary
interaction parameters for the liquid solution model. In each of the four calculated ternary liquidus projections, the region of
composition corresponding to room temperature ionic liquid mixtures was determined. The global minimum of the liquidus
temperature in the complete composition space was calculated to be about −16 °C, with a mole percentage composition of
(33.8% [C3mpyrr][PF6] + 33.9% [C3mpy][PF6] + 32.3% [C3mim][PF6]).
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Citação
Mirarabrazi, Meysam; Martins, Mónia A.R.; Pinho, Simaõ P.; Coutinho, Joaõ A.P.; Robelin, Christian (2019). Solid-Liquid Equilibria for Hexafluorophosphate-Based Ionic Liquid Quaternary Mixtures and Their Corresponding Subsystems. Journal of Physical Chemistry B. ISSN 1520-6106. 123, p. 8954-8969