In this article, we study the behavior of an ionic liquid (IL) derived from pyridinium, 1-butyl-3-methylpyridinium
tetrafluoroborate [b3mpy][BF4], in mixtures with water and with the first alkanols of the series from methanol to
butan-1-ol, at the temperatures of (298.15 and 318.15) K. First, the miscibility regions with the alkanols were
established at these two temperatures, determining experimentally the liquid−liquid equilibria and the upper critical
solution temperature (UCST) for each binary mixture, confirming the quasiexponential variation of the UCST
with the alkanol chain. The enthalpies
were determined experimentally with a newly designed calorimetric
cell, and the excess molar volumes
were determined from densities, at (298.15 and 318.15) K. In all cases, the
are positive with (d
/dT)p > 0, whereas the
are negative for mixtures with alkanols but positive for the
mixture of IL + water. The thermal coefficient (d
/dT)p > 0 was also positive in all cases. All data were
correlated with a suitable polynomial equation, and the area and volume parameters of [b3mpy][BF4] were
calculated. Finally, we give an interpretation of the results and of the behavior of the mixtures.
a b s t r a c tThe temperature and enthalpy of fusion of choline chloride -[Ch]Cl-are not directly measurable since this compound decomposes upon melting. Yet, given the wide use of this compound in the preparation of deep eutectic solvents (DES), its thermophysical fusion properties are very important for a better understanding of these mixtures and the thermodynamic description of their solid-liquid phase diagrams. In this work, the fusion properties of choline chloride were estimated using the solubility curves of choline chloride in ten different ionic compounds, forming simple binary eutectic mixtures with quasiideal liquid phases. Experimental solid-liquid equilibria data for these systems -[Ch]Cl þ ionic compounds-were measured, and the ideality of the systems assessed through the quantification of the activity coefficients and their comparison in each pair of binary solutions. The values estimated for the fusion properties of choline chloride are T fus, [Ch]Cl ¼ 597 ± 7 K and D fus H [Ch]Cl ¼ 4300 ± 600 J mol À1 . These were additionally checked by thermodynamic consistency tests and by the prediction of the solid-liquid curves with COSMO-RS model. The results obtained with both procedures allow us to guarantee the usefulness and robustness of the estimated data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.