Study on the Morphology Feature of 1-Butyl-3-methylimidazolium Tetrafluoroborate Based Ionic Liquid Reverse Microemulsions

The micromorphology of 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF₄)-in-cyclohexane and bmimBF₄-in-triethylamine ionic liquid microemulsions was investigated by two-dimensional NMR and freeze-fracture transmission electron microscopy. The reverse micelles of Triton X-100/cyclohexane were destroyed by adding bmimBF₄ and reverse microemulsions were induced to form by successively adding bmimBF₄. However, no micelles appeared in triethylamine. But if adding bmimBF₄ to a certain extent, a reverse microemulsion was also formed. The driving force of such aggregations could be attributed to the presence of different types of interactions between Triton X-100 and bmimBF₄. A staggered arrangement of surfactant led to the irregular droplet structure and large aggregate size.