FLUORESCENCE STUDIES ON MIXED MICELLES OF IONIC-NONIONIC SURFACTANTS

Fluorescence properties of ionic dyes using oppositely charged non-flu orescent dyes as quenchers in mixed surfactant of ionic-nonionic syste ms have been investigated. Cationic dye safranin O and anionic dye eos in Y are used as probes; bromocresol green, thymol blue and bromothymo l blue are used as quenchers for safranin O, and crystal violet, tolui dine blue and methylene blue are used as quenchers for eosin Y. The fl uorescence characteristics in mixed micellar media of ionic and nonion ic surfactants CTAB, CpC1, SDS, AOT, Triton X-100, Tween 20, and Brij 35 have been studied. The variations ill the physico-chemical paramete rs. viz., cmc, aggregation number(n), binding constant between the que ncher and the probe (K-sv), occupancy number of the quencher in the mi celles ((n) over tilde), thee binding constant of the quencher with th e micelle (K) in such interactions have been evaluated using suitable equations and the properties have been explained in terms of the micel lar structures.