Using 1-methylimidazole as a starting material, six conventional and four functionalized ionic liquids have been prepared, which were 1-butyl-3-methylimidazolium tetrafluoroborate and hexafluorophosphate ([bmim][BF₄] and [bmim][PF₆]), 1-hexyl-3-methylimidazolium tetrafluoroborate and hexafluorophosphate ([hmim][BF₄] and [hmim][PF₆]), 1-hexadecyl-3-methylimidazolium tetrafluoroborate and hexafluorophosphate ([C₁₆mim][BF₄] and [C₁₆mim][PF₆]), 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate and hexafluorophosphate ([2-hemim][BF₄] and [2-hemim][PF₆]), 1-ethoxycarbonylmethyl- 3-methylimidazolium tetrafluoroborate and hexafluorophosphate ([eocmmim][BF₄] and [eocmmim][PF₆]). In order to develop the application to perfume and aroma cosmetics, physical properties of these ionic liquids have been studied. Their solubilities in various organic solvents were determined and discussed, and their surface tension and foaming capabilities were also determined. The results show that only [C₁₆mim][BF₄] and [C₁₆mim][PF₆] are of foaming capability, which is 68 and 120 mm individually.

Key words: ionic liquid, functionalized ionic liquid, preparation, surface active agent