EFFECTS OF SOLVENT AND MICELLAR ENVIRONMENT ON THE SPECTROSCOPIC BEHAVIOR OF THE DYE SAFRANINE-T

The photophysical (visible and fluorescence) behaviour of the dye safr anine T has been studied in several polar and non-polar solvents and i n micellar solution (non-ionic and ionic surfactants). The change in t he dipole moment of the dye between the ground and excited states has been estimated using approximate solvent-induced spectral shift (Stoke s shift) theories based on non-specific interactions. The dependence o f the dye behaviour on the nature of the micellar interface is shown b y the Stokes shift which exhibits an inverse dependence on the average aggregation number of the surfactant micelles. A reasonable estimatio n of the dielectric constant of the micellar interface has been attemp ted.