Photophysical Studies of Erythrosin B Dye in Aqueous Micellar Dispersions of Different Surfactants and in Different Solvents

Abstract

Photophysical behavior of a xanthene dye Erythrosin B (EB) have been studied by ultraviolet-visible absorption and fluorescence spectroscopic measurements in presence of different nonionic surfactants and different solvents. From the thermodynamic and spectrophotometric results, it can be concluded that the electron donating abilities of the nonionic surfactants towards EB are in the order: Tween 60 > Tween 40 > Tween 20. An attempt has been made to ascertain the polarity of the microenvironment of Erythrosin B in the nonionic surfactant media from the photophysical characteristics of the dye in different solvents of known polarities.

Keywords:

• Binding constant
• Erythrosin B
• nonionic surfactant
• solvent effect
• Stokes shift

Acknowledgments

The authors are thankful to the Department of Chemistry, Tripura University, for providing laboratory facilities and also to U.G.C, Govt. of India for supporting financial assistance through Research Eligibility Test and CSIR Project No. 01(2289)/08/EMR-II dt.20-11-2008, (to R. K. Nath).

Notes

^a The dielectric constant and refractive index values have been collected from [51].

^b Kosower Z values have been taken from [52].

^c These values have been estimated from our study.