Properties modification by eutectic formation in mixtures of ionic liquids

The composition and temperature of three eutectic mixtures were determined at atmospheric pressure in systems resulting from the combination of pairs of ionic liquids where each ionic liquid was constituted by only one type of cation and only one type of anion. In addition, the three pairs investigated had a common ion (either the cation or the anion), thus totalising just three different ions in the resulting mixture. All three eutectic mixtures had a temperature near the ambient one, meaning a decrease of up to ca. 50 K with regard to the melting temperature of the parent ionic liquids. A characterisation of physical properties (density, viscosity, and surface tension) of the eutectic mixtures was carried out, and compared as appropriate with those of the parent compounds.