| Ionic liquids with a hydrophilic group and a hydrophobic group could bedesigned and synthesized as surfactants which may self-aggregate to micelles, liquidcrystals, vesicles and microemulsions in aqueous solution. Previous reports havedescribed the formation of imidazolium ionic liquid surfactant micelles, however,most of these studies focus on the micelles with an imidazolium group as thehydrophilic part in aqueous solution. This dissertation aims to design and synthesizenew ionic liquid surfactants which could form the micelle with imidazolium group ashydrophobic internal while polyethylene glycol as hydrophilic external to realize theseparation of the aqueous solution outside and ionic liquid inside. In this way, wecould obtain the ionic liquid microenvironment in micelles. The main results aredescribed in the following paragraphs：(1) Design and synthesize the ionic liquid surfactants via one-step and two-stepmethods using polyethylene glycol monomethyl ether as hydrophilic part and1-butyl-3-imidazol-hexane bis (trifluoromethyl methane) imide ionic liquid as hydrophobicpart. Six kinds of ionic liquids were synthesized and further characterized by nuclearmagnetic resonance, elemental analysis, and mass spectrometry.(2) The measurements of melting points for these ionic liquids demonstrate thatthe melting point could be significantly affected by anions. The melting point of theionic liquid with bromide ions as the anoin are usually higher than that with bis(trifluoromethanesulfonyl) imide ion as the anion, and the longer the polyethyleneglycol chain is, the higher the melting point is.(3) The micelles of N-butyl-N’-hexanoic acid (3,5-bis (2-(2-(2-methoxyethoxy) ethoxy) ethoxy)) benzyl ester imidazole bis (trifluoromethane) imide（ionic liquid2）, N-butyl-N’-hexanoic acid (polyethylene glycol monomethyl ether350) imidazole ester bis (trifluoromethanesulfonyl) imide （ionic liquid4） andN-butyl-N’-hexanoic acid (polyethylene glycol monomethyl ether350) imidazoleester bis (trifluoromethanesulfonyl) imide （ionic liquid6） were obtained.Furthermore, the critical micelle concentrations were measured, and transmission electron microscopy was employed to characterize the morphology of these micelles.The results show the poor solubility of ionic liquid2and4in water. Nevertheless,ionic liquid6displays good solubility in water and forms micelles spontaneously inwater with the critical micelle concentration of0.0112g/L.(4) We measured the cloud point of the six ionic liquids. The ionic liquids withbromide ions as the anoin can dissolve in the water with no cloud point. In contrast,the ionic liquid6can dissolve in water and its cloud point decreases with the increaseof concentration, which is similar to the conventional non-ionic surfactant with apolyethylene glycol chain. |
