Spectrofluorometric studies on the intermolecular interaction in some aqueous surfactant-polymer solutions

Abstract

Using anthracene as a fluorescence probe, the intermolecular interaction in sodium dodecyl sulphate (SDS)+poly(N-vinyl-2- pyrrolidone) (PVP) and bis(2-ethylhexyl sulphosuccinate sodium salt) (AOT)+polyvinyl alcohol (PVA) in aqueous solutions have been investigated. From the observed vibronic band intensity ratio, <i>I</i>₁/<i>I</i>₃<i>, </i>(at λ_em = 340 nm and λ_em = 404 nm), in the fluorescence spectra of 10^-6 mol dm^-3 anthracene as a function of surfactant concentration, the order of polarity of microenvironment around the probe in aqueous surfactant+polymer solutions has been assessed. Fluorescence data show that binding of premicellar aggregates of anionic surfactant, SDS, with PVP takes place, over the surfactant concentration of 3-15 mmol dm^-3 prior to usual micelle formation. However, in the case of AOT +PVA, instead of binding of surfactant with the polymer, formation of mixed micelles having CMC value lower than that for pure AOT has been observed.