DYE SOLUBILIZATION IN POLYELECTROLYTE MICELLE COMPLEXES

The solubilization of the hydrophobic dye Solvent Orange 2 has been measured in soluble complexes formed between mixed anionic/nonionic micelles and a strong polycation. In the system studied, comprising mixed micelles of sodium dodecyl sulfate and Triton X-100 with poly(dimethyldiallylammonium chloride), soluble complexes are formed over a range of micelle compositions, ionic strengths, and polymer concentrations. These parameters were adjusted to ensure that the predominant state of the surfactant was in the form of polymer-bound micelles. Under these conditions, neither the apparent CMC nor the net solubilization efficiency of the surfactant was different from the behavior of the polymer-free system. These results, taken together with turbidimetric titrations reported here, indicate that, despite the evident interaction between the polyion and the micelle, complex formation does not significantly alter the free energy of micellization, and does not produce major changes in structure of the micelle. © 1991.