Spectral Studies of Merocyanine 540 in Aqueous Solution of Different Surfactants

The absorption spectra of merocyanine 540 (MC 540), an anionic dye are perturbed in aqueous solution containing cationic, anionic and nonionic surfactants. The results show that MC 540 forms 1:1 electron-donor-acceptor (EDA) or charge-transfer (CT) complexes with all the nonionic surfactants. The thermodynamic properties of these complexes have been determined along with the spectral characteristics. There is an electrostatic interaction between the dye and CTAB, a cationic surfactant while the hydrophobic interaction of the dye with SDS, an anionic surfactant is observed.