Physicochemical investigations on the interaction of surfactants and saltswith polyvinylpyrrolidone in aqueous medium

Microcalorimetric investigations have been carried out on the interaction o f the surfactants sodium cholate, sodium deoxycholate, tetradecyltrimethyla mmonium bromide, cetyl(hexadecyl) trimethylammonium bromide, and p-tert-oct ylphenoxy polyoxyethylene ether (Triton X-100) and the salts potassium iodi de, sodium benzoate, sodium bromide, and sodium salicylate with the neutral polymer polyvinylpyrrolidone: (PVP). The enthalpy of dilution of the surfa ctants has been measured in the absence and presence of the polymer and the results are compared to determine the effect of PVP on the micellization o f the surfactants and the energetics of the process. As well, the micelliza tion activity of the surfactants in the presence of the polymer has been st udied by conductometric and fluorimetric methods. The enthalpy of dilution of the salts has been measured to provide an understanding of the nature an d magnitude of their interaction with PVP. (C) 2001 Academic Press.