A spectroscopic study of hemicyanine dyes in anionic micellar solutions

The interaction of amphiphilic hemicyanine dyes i.e. (dialkylamino)stilbazo lium butyl sulphonate (R = -CH3 to -C5H11) With sodium dodecyl sulphate (SD S), an anionic surfactant, in the process of solubilization was studied by absorption spectra as a function of surfactant concentrations above and bel ow critical micelle concentration. Absorption spectra showed a red shift fo r dyes with small dialkyl chains and a blue shift for dyes with long dialky l chains. Electronic transition energies (Delta E-T) and the approximate nu mber of dye molecules incorporated per micelle were estimated at particular surfactant concentrations. Hydrophobic-hydrophilic force balance plays an important role in the process of solubilization of dyes in aqueous micellar solution. (C) 1999 Elsevier Science S.A. All rights reserved.