Characterization of Pyrene Solubilization in Selective Micellar Media of Novel Bio-degradable Natural Surfactant Saponin (Extracted from Soap Nut) and Conventional Surfactant SDBS in Presence and Absence of Common Salt NaCl

Abstract

Solubilisation of pyrene (PAHs) in aqueous micellar solutions of natural surfactant saponin and conventional surfactant sodium dodecylbenzene sulfonate (SDBS) has been examined by UV-Vis and steady state fluorescence spectrometry at 30°C. The effect of addition of common salt NaCl on the I₁/I₃ of fluorescence has also been determined. The experiment concludes that the pyrene molecules were incorporated in the palisade layers of both micelles because of their hydrophobic character. The interaction of pyrene with a neutral saponin micelle resulted in a red shift of UV absorption spectra, while the negative headed surfactant SDBS showed no such phenomena. The resulting thermodynamic parameters proved the better efficiency of the bio-surfactant saponin for the solubilization of pyrene with respect to that of the conventional surfactant SDBS. With increasing ionic strength (on addition of NaCl) the solubilization of pyrene was found to be better and effective in both the surfactant mediums.