Mutual phobicity fluorocarbon chains

However, no systematic investigation of adsorption and micellization of the alcohol-fluorocarbon (FC) surfactant mixture has been made. Other studies have examined the "mutual phobicity" between the hydrocarbon (HC) and FC chain in the mixed system of FC and HC surfactants (5-10) It is expected that "mutual phobicity" should be observed in the alkyl alcohol-FC surfactant system.too. In this... 

Esumi et al. [71] arrived at a similar conclusion when studying the adsorption of binary mixtures of cationic surfactants, bis(2-hydroxyethyl) (2-hydroxy-3-perfluorooctylpropyl)methylammonium chloride and hexadecylpyridinium chloride from their solution in water to negatively charged silica. The total adsorption of the mixture was found to be lower than that of single surfactants adsorbed separately, indicating a mutual phobicity between hydrocarbon and fluorocarbon chains. 

Asakawa et al. [202] examined solubilization of octafluoronaphthalene (OFN) and pyrene by anionic surfactants with a fluorocarbon or hydrocarbon hydrophobe and their mixtures. The study confirmed the dependence of solubilization on mutual phobicity between the solubilizate and surfactant chains, as well as the micellar size. The replacement of the lithium counterion with the diethylam-monium counterion increased solubilization of OFN by perfluorononoate and tetradecyl sulfate. The solubilization increase was attributed to an increase in micellar size and counterion binding. The positive effect of micellar size on solubilization was demonstrated by an adding salt (LiCl) or by mixing surfactants. 

The effect of additives on mesophases of fluorinated surfactants has been studied by Tiddy and Wheeler [ 163] and Rosenblatt [176]. Tiddy and Wheeler described the effects of -octanol on the ammonium perfluorooctanoate-water system with a three-component phase diagram (Fig. 7.39). The main differences between phase diagrams for this system and that for sodium octanoate- octanol-water were related to mutual phobicity between fluorocarbon and hydrocarbon chains. Octanol was found to be less soluble in the aqueous micellar phase of ammonium perfluorooctanoate than that of sodium octanoate. However, ammonium perfluorooctanoate is more soluble in octanol than sodium octanoate. This solubility difference is probably related to the effect of counterions, as ammonium salts are usually more soluble in octanol than sodium salts. 

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