Microcalorimetric, Conductometric, Fluorimetric and Dynamic Light Scattering Investigations on the Interaction of Sodium Dodecyl Sulphate and Sodium Bis(2-Ethyl Hexyl) Sulphosuccinate with Polyvinylpyrrolidone

The interactions of SDS and AOT with PVP have been investigated by microcalorimetric, conductometric, fluorimetric and dynamic light scattering methods. The occurrence of a CAC and a CMC have been observed in microcalorimetric measurements, but were not clearly evident in the conductometric and fluorimetric experiments. From the microcalorimetric results, the energetics of CAC and CMC formation have been computed. The conductometric method has indicated two CMC points and the extent of counter ion binding to the aggregated SDS. Similar data for AOT remain inconclusive. Fluorimetric results indicating a decline in the polarity of the environment of a pyrene probe permitted the estimation of a single CMC for both SDS and AOT in PVP solution. The aggregation numbers of SDS and AOT have been found to be independent of the PVP concentration. DLS measurements have shown an increase in the hydrodynamic diameter of the polymer upon interaction with the surfactants.