Evaporation/Decomposition Behavior of 1-Butyl-3-Methylimidazolium Chloride (BMImCL) Investigated through Effusion and Thermal Analysis Techniques

The evaporation/decomposition behavior of the ionic liquid 1-butyl-3-methylimidazolium chloride (BMImCl) was studied with various techniques, such as thermogravimetry (TG), Knudsen effusion mass loss (KEML), and spectrometry (KEMS), in order to investigate competition between simple evaporation gaseous ion pairs (NIP: neutral pair) thermal decomposition releasing volatile species. TG/DSC experiments were carried out from 293 823 K under both He N2 flowing atmospheres on BMImCl well BMImNTf2 (NTf2: bis(trifluoromethylsulfonyl)imide). Both liquids found undergoing a single step temperature range investigated. However, while occur different ranges, depending inert gas used, TG curves helium nitrogen flow practically superimposable, thus suggesting occurrence decomposition. Furthermore, KEML (in 398 481 K) indicated clear dependence unit area rate hole diameter, an effect not observed for ILs NTf2 anion. Finally, KEMS measurements 416–474 allowed us identify most abundant species vapor phase, which resulted methyl chloride, butylimidazole, butyl methylimidazole, probably formed liquid.