Phase Behavior and Solubilization of Microemulsion Systems Containing Imidazolium Type Surfactant CnmimBr and Butyric Acid as Cosurfactant

Abstract

Abstract The phase behavior and solubilization of two microemulsion systems 1-alkyl-3-methylimidazolium bromide (CnmimBr, n = 12,14,16)/butyric acid/hexane/brine (5% NaCl) and CnmimBr/1-butanol/hexane/brine (5% NaCl) were studied and compared. The physico-chemical parameters, such as the solubility (∊ B ) of the cosurfactant, the mass fraction of the cosurfactant in the interfacial layer (AS ), and the solubilization ability (SP*) of the two microemulsion systems were calculated and discussed. As the carbon chain length of CnmimBr molecules increases, SP* increases, and the difference of SP* values between the two microemulsion systems is reduced. The effects of aqueous and oleic phases and temperatures on the phase behavior and solubilization of C14mimBr/butyric acid/alkane/aqueous phase microemulsion systems were also discussed.