Indirect assessment of the fusion properties of choline chloride from solid-liquid equilibria data

authors	Fernandez, L; Silva, LP; Martins, MAR; Ferreira, O; Ortega, J; Pinho, SP; Coutinho, JAP
nationality	International
journal	FLUID PHASE EQUILIBRIA
author keywords	Choline chloride; Deep eutectic solvents; Melting properties; Experimental Ideal solutions
keywords	DEEP-EUTECTIC-SOLVENTS; IONIC LIQUIDS; PHYSICAL-PROPERTIES; BINARY-MIXTURES; BEHAVIOR
abstract	The 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 quasi ideal liquid phases. Experimental solid-liquid equilibria data for these systems-[Ch]CI + 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 Tfus,lchlcl = 597 +/- 7 K and Delta H-fus([ch]CI) = 4300 +/- 600 J mot(-1). 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. (C) 2017 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	0378-3812
isbn	1879-0224
year published	2017
volume	448
beginning page	9
ending page	14
digital object identifier (doi)	10.1016/j.fluid.2017.03.015
web of science category	Thermodynamics; Chemistry, Physical; Engineering, Chemical
subject category	Thermodynamics; Chemistry; Engineering
unique article identifier	WOS:000405767200003