A comparison study between sodium decyl sulfonate and sodium decyl sulfate with respect to the interaction with poly(vinylpyrrolidone)

Surface tension, fluorescence quenching, and intradiffusion measurements have been performed on sodium decyl sulfonate and sodium decyl sulfate aqueous solutions in the presence and in the absence of poly(vinylpyrrolidone). Despite their chemical similarity, these two surfactants show differences in their behavior even in binary aqueous solution. In fact, the cmc values are different as are their aggregation numbers. Furthermore, the overall picture of the properties we have studied suggests the presence of a preferential interaction of poly (vinylpyrrolidone) toward sodium decyl sulfate with respect to sodium decyl sulfonate, for which no complex formation has been detected. The aqueous poly(vinylpyrrolidone)sodium decyl sulfate system has been extensively studied in order to obtain details on the micellar aggregates bound on the polymer. This includes an estimation of the number of micellelike clusters per polymer molecule and the number of surfactant molecules present in these micelles.