ABSTRACT
The interaction of cationic dye, acridine orange (AO) with two anionic polyelectrolytes, namely, sodium heparinate (NaHep) and sodium alginate (NaAlg) has been investigated by spectrophotometric method. The polymer 178 induced metachromasy in the dyes resulting in the shift of the absorption maxima of the dyes towards shorter wavelengths. The stability of the complexes formed between AO and NaAlg was found to be greater than that formed between AO and sodium heparinate. This fact was further confirmed by reversal studies using alcohols, urea surfactants, and electrolytes. The interaction parameters revealed that binding between AO and anionic polyelectrolytes was mainly due to electrostatic interaction. A comparative account of stoichiometry, stability of complexes formed, and thermodynamic parameters of interaction have been reported. The nature of the interaction between the polymer and the dyes has been discussed in detail. Moreover, the fluorescence spectra of the dye with the polymers have also been reported and the values of Stern-Volmer constant have been evaluated.
