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

The photophysical (visible and fluorescence) behaviour of the dye safranine T has been studied in several polar and non-polar solvents and in micellar solution (non-ionic and ionic surfactants). The change in the dipole moment of the dye between the ground and excited states has been estimated using approximate solvent-induced spectral shift (Stokes shift) theories based on non-specific interactions. The dependence of the dye behaviour on the nature of the micellar interface is shown by the Stokes shift which exhibits an inverse dependence on the average aggregation number of the surfactant micelles. A reasonable estimation of the dielectric constant of the micellar interface has been attempted.