Abstract.
In the mixed micelles of an ionic surfactant (sodium dodecyl sulfate) with a nonionic surfactant (N-decanoyl-N-methylglucamide, hexaoxyethylene glycol-mono-n-decylether, and hexaoxyethylene glycol-mono-n-dodecylether), the critical mole fraction, X ic, of the ionic surfactant has been determined, below which the counterion is completely released from the micelles. The values of X ic are 0.074, 0.11, and 0.11, for the respective nonionic surfactants. The valences, i.e., the aggregation numbers of the ionic surfactant, of the mixed micelles at X ic are almost close to each other, around 6. At X ic, the critical surface charge density (about 0.03 Cm–2) for counterion condensation was tentatively calculated. In the present study, a differential conductivity method was applied.
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Manabe, M., Funamoto, M., Kohgami, F. et al. Critical composition of ionic–nonionic mixed micelles for counterion condensation. Colloid Polym Sci 281, 239–245 (2003). https://doi.org/10.1007/s00396-002-0764-2
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DOI: https://doi.org/10.1007/s00396-002-0764-2