Absorption and emission spectroscopic studies of fluorescein dye in alkanol, micellar and microemulsion media

The photophysical behaviours of the dye fluorescein have been studied in al kanols (methanol to decanol), in micellar solutions of SDS, CTAB and Triton X-100 and in the w/o microemulsion system of water/AOT/heptane. The alkano ls are found to affect the absorption and fluorescence spectra of the dye. On the basis of the solvent adsorption model the binding constants of the d ye with the alkanols have been estimated. The absorption and emission spect ra of the dye are observed to be influenced by the ionic surfactants SDS, C TAB and not influenced by the non-ionic representative Triton X-100. The re sults confirm formation of a 1:1 complex of the dye with SDS and CTAB micel les. In the w/o microemulsion medium, the photophysical behaviours of the d ye are found to be different from non-aqueous and micellar media. (C) 1999 Elsevier Science S.A. All rights reserved.