Liquid temperature range of two ionic liquids (ILs) with the common cation, Choline, is determined in this work. The selected ILs are Choline tosylate [Chol][Tos] and Choline dicyanamide [Chol] [DCN].

The lower limit of liquid range is given by solid-liquid transitions and it is determined using differential scanning calorimetry (DSC) [1]. Upper limit is given by degradation temperature which is determined using the thermogravimetric technique (TGA) [2]. Dynamic and isothermal methods have been combined to estimate the maximum operation temperature.

Additionally, a deeper study of the effect of the heating and cooling rate on the temperature and shape of the transitions observed in DSC curves of [Chol] [DCN] was performed.

A common trend has been observed for melting and degradation temperatures of selected liquids:

[Chol][DCN]< [Chol][Tos]

Acknowledgments

This study was financed by the project EM2013/031 (Xunta de Galicia, Spain) and the network REGALIS R2014/015 (Xunta de Galicia, Spain).

References

[1] M. Villanueva, J. J. Parajó, P.B. Sánchez, J. García, J. Salgado, J. Chem. Thermodyn. 91, 127 (2015).

[2] J. Salgado, J. J. Parajó, J. Fernández, M. Villanueva, J. Chem. Thermodyn. 74, 51(2014).