Advisor(s)
Abstract(s)
The high melting point of a large number of organic salts with potential ionic liquid-like properties,
hinders their applicability as solvents. Considering the success of cholinium chloride on lowering the
melting temperature of several substances and its success on forming deep eutectic solvents, this work
studies its mixing with organic chlorides to lower their melting points producing eutectic ionic liquids.
The solid-liquid phase diagrams for binary mixtures composed of cholinium chloride and ten organic
halides were experimentally measured. Surprisingly, cholinium chloride presented, for all these systems,
significant positive deviations from ideal liquid behaviour that restricted its ability to lower the melting
points of these mixtures. Only for mixtures with ammonium chloride, tetramethylammonium chloride,
bis(2-hydroxyethyl)dimethylammonium chloride or cholinium bromide was cholinium chloride able to
significantly lower the melting point of the mixture, but without reaching values close to room temperature
(298 K). For a better understanding of the results obtained, the solid-liquid phase diagrams of
four alkylammonium chloride-based mixtures were experimentally assessed and used to show that
these compounds are better than cholinium chloride at inducing negative deviations from ideality,
leading to greater melting point depressions.
Description
Keywords
Cholinium chloride Eutectic solvents Ionic liquid mixtures Ionic liquids Solid-liquid equilibria
Citation
Abranches, Dinis O.; Silva, Liliana P.; Martins, Mónia A.R.; Fernandez, Luis; Pinho, Simão P.; Coutinho, João A.P. (2019). Can cholinium chloride form eutectic solvents with organic chloride-based salts?. Fluid Phase Equilibria. ISSN 0378-3812. 493, p. 120-126