MEDLINE Journals

    Micelle Formation of Dodecylammonium Surfactant with Mixed Counterions: Perfluorocarboxylate and Alkanesulfonate Ions


    Sugihara G, Era Y, Funatsu M, et al. 


    J Colloid Interface Sci 1997 Mar 15; 187(2) :435-42.


    Micelle formation was studied for four mixing combinations of dodecylammonium (DA) salts having perfluorocarboxylate ions (trifluoroacetate (PA) and pentafluoropropionate (PP) and alkane sulfonate ions (methane sulfonate (MS) and ethane sulfonate (ES)) as their counterions, i.e., DAPA/DAMS, DAPA/DAES, DAPP/DAMS, and DAPP/DAES. The fluorocarbon anions as counterions exhibited that the degree of counterion binding to micelle (beta) as well as the extent of stabilizing micelles and lowering ability of critical micellization concentration (CMC) are greater than hydrocarbon anions. The "mixed micelle formation" was examined in terms of CMC as a function of mole fraction (Xi) in each surfactant mixture. The CMCs of the mixed surfactant systems studied here, correspond to those of "surfactant with mixed counterions". However, by regarding tentatively those combinations as binary mixed surfactant systems, the CMC vs Xi curves (singly dispersed phase curves) as well as CMC vs micellar composition (Yi) curves (micellar phase curves) were simulated by applying the present authors' and Rubingh's equations which have been derived respectively with and without taking into account mutual added-salt effect (or the beta value for each pure system). A negative deviation from ideal mixing was observed for each combination, indicating that mixing of fluorocarbon anion with hydrocarbon anion as counterion of DA salts results in more stabilized micelle formation. Plotting the derivative of specific conductance (kappa) by total concentration of surfactant (Ct), dkappa/dCt against Ct, the curves showed a constant value at the sufficiently higher concentration range than CMC, and the constant values were found able to be related to the degree of dissociation of micelles (alpha). Even for the mixed systems, the alpha or beta values were estimated from the conductivity data. The greater power to stabilize micelle formation by fluorocarbon ions was interpreted on the basis of concept of "contact hydrophobic interaction" proposed by Mukerjee (Mukerjee, P., Colloids Surf. A: Physicochem. Eng. Aspects 84, 49 (1994)).



    Pub Type(s)


    PubMed ID


    Content Manager
    Related Content

    Blending effects on adsorption and micellization of different membrane protein solubilizers II. A thermodynamic study on a mixed system of CHAPS with a bile salt in pH 7.4 phosphate buffer solution.

    Aggregation behavior of fluorocarbon and hydrocarbon cationic surfactant mixtures: a study of 1H NMR and 19F NMR.

    Micelle Formation of Anionic Surfactant with Divalent Counterion of Separate Electric Charge.

    Micellization of Mixed System of Bile Salt and Nonionic Surfactant: Sodium Deoxycholate and Decanoyl-N-methylglucamide.

    Modeling counterion binding in ionic-nonionic and ionic-zwitterionic binary surfactant mixtures.

    Blending effects on adsorption and micellization of different membrane protein solubilizers: a thermodynamic study on three mixed systems of CHAPS with MEGA-8, -9 and -10 in pH 7.2 phosphate buffer solution.

    Critical micelle concentrations and interaction parameters of aqueous binary surfactant:ionic surfactant mixtures.

    Micelle Formation of n-Decyltrimethylammonium Perfluorocarboxylates