The water content in all obtained products was measured with a TitroLine 7500 KF trace apparatus (SI Analytics, Germany) using the Karl Fischer titration method according to the previously described procedure. The purity of the synthesized quaternary ammonium bromide, as well as ionic liquids following the ion exchange reaction, was assayed by a process of direct two-phase titration according to EN ISO 2871-1:2010. Differential scanning calorimeter (DSC) was performed under nitrogen atmosphere using DSC 209 F1 Phoenix unit (Netzsch, Germany). Samples between 5 and 20 mg were placed in platinum pans and were heated from 25 to 120 °C at a heating rate of 10 °C min -1 and cooled at a cooling rate of 10 °C min -1 to -80 °C. After that, samples were heated again to 120 °C and subsequently cooled to 25 °C.