Fluorocarbon hybrid surfactants characterization of admicelles and its solubilization

Admicelle formation of the fluorocarbon hybrid surfactant 1-oxo-1-[4-(fluor oalkyl)phenyl]-2-alkanesulfonate (FCm-HCn) on the aluminum oxide particle s urface has been studied by the adsorption isotherm, zeta-potential of the p article surface, degree of counterion dissociation, contact angle, and pyre ne fluorescence probe measurement. Solution properties of FCm-HCn have been compared with a dialkyl hydrocarbon surfactant, sodium 1-4-alkylphenyl-1-o xo-2-alkanesulfonate (HCm-HCn). Adsorption isotherm study and zeta-potentia l measurement indicate that the fluorocarbon hybrid surfactant can adsorb o n the aluminum oxide surface at lower concentrations than the hydrocarbon s urfactant. Furthermore, the total amount of surfactant adsorbed on the alum inum oxide surface is higher than that of the hydrocarbon surfactant. A pyr ene fluorescence probe study shows that pyrene molecules are solubilized ne ar the hydrocarbon chain of the surfactant molecules, indicating that the h ydrocarbon domain exists in the fluorocarbon hybrid surfactant admicelle. N o pyrene excimer formation is observed in the hybrid surfactant admicelle b ut in the hydrocarbon surfactant, implying the hybrid surfactant molecules are packed tightly in the admicelle. In addition, the admicelle of the hybr id surfactant is capable of solubilizing both 2-naphthol and 1-trifluoromet hyl-2-naphthol and the total amount of solubilized solute increases with in creasing surfactant concentration.