ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Kinetic and thermodynamic measurements were carried out on mixtures of ionic hydrocarbon- and perfluoro detergents. As systems the two combinations C8F17SO3N(CH3)4/C14H29SO4N(CH3)4 and C8F17SO3Li/C12H25SO4Li were used. The critical micelle concentrations (cmc) of the mixtures are higher than the cmc-values of the pure components, but lower than the values which would be observed if no mixed micelles were formed. This result is a clear indication of the existence of mixed micelles. The kinetic data on the C8F17SO3N(CH3)4/C14H29SO4N(CH3)4 mixtures show that the mixed micelles have considerably lower aggregation numbers than the pure micelles. The large aggregates that are responsible for the viscoelastic behaviour of solutions of C8F17SO3N(CH3)4 are not detectable in the detergent mixtures. The mean residence time of a detergent ion is lower in the mixed micelles than in the pure micelles. The solubility of a perfluoro-detergent in a hydrocarbon micelle is higher than vice versa. For the C8F17SO3Li/C12H25SO4Li combination the observed concentration of micellar nuclei is several orders of magnitude larger for the perfluoro system than for the hydrocarbon system. As a consequence, in mixtures up to a mole fraction of 0,8 of hydrocarbon detergent, the micelles are formed via nuclei of the perfluoro detergent.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1980.021811115
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