Property of the Mixed Aqueous Solution of Fluorocarbon and Hydrocarbon Surfactants

Abstract

The change in micelle formation of a hydrocarbon surfactant such as lithium dodecyl sulfate(LiDs) by the addition of a fluorocarbon surfactant of lithium perfluoro-1-octanesulfonate(LiFOS) was studied by using the change of keto-enol tautomerism of(benzoylaceto)anilide(BZAA)in micelle. This change on absorption spectra of BZAA in mixtures was discussed with the results of the salt effect and the conductivity of mixed solution of LiFOS(or 1/2 Li2SO4)and LIDS. From these results, in the range of low concentration of LiDS and LiFOS, the mixed micelle was found to be hardly formed in the mixed system of both surfactants as well as in the mixed system of two kinds of ordinary hydrocarbon surfactants, and some of the LiFOS molecules acted as a salt on LiDS molecule in aqueous solution and viceversa. In the ranges of higher concentration of two surfactants, the mixed micelle between LiFOS and LiDS was formed in aqueous mixed solution, and the conductivity of the solution showed different behavior in comparison with the mixed solution of two kinds of hydrocarbon surfactants.