MODIFICATION OF MOLECULAR-PROPERTIES OF SOME DYES IN SODIUM DODECYL-SULFATE (SDS) MICELLAR AQUEOUS-SOLUTION

The influence of SDS upon the molecular properties of proflavine (3,6- diaminoacridine), acridine yellow (2,7-dimethyl-3,6-diaminoacridine) a nd methylene blue (3,7-bis-dimethylamino-phenothiazine) was studied co mparatively to their properties in that of aqueous media. The absorpti on and emission spectra of the three dyes in SDS aqueous solution (1-1 00 mmol/l) were recorded. The spectroscopic data also allowed the eval uation of the critical micellization concentration (CMC), acidity cons tants in fundamental (pK(a)) and excited (pK(a)) states, and lifetime s of excited singlet states.