The Effect of PVP on the Solubilization of Benzyl Alcohol in Various Surfactants

The solubilization location and amount of benzyl alcohol in various kinds of surfactant micelle solutions with addition of the PVP（polyvinylpyrrolidone）and without have been investigated by high resolution proton nuclear magnitic resonance spectroscopy（¹H-NMR）and spectrophotometry The results obtained that for the anionic surfactant SDS（sodium dodecyl sulfate）, PVP may increase the radius of SDS micelle, and make the solubilization amount increase At low concentration of the benzyl alcohol that is solubilizated by adsorption at the micelle-water“interface”, with further added benzyl alcohol, its solubilization is probaly localized in the palisade layer It is orientated in such a manner that the polar group located the micellar surface and aromatic ring is directed toward the micellar interior, while NMR spectrum splited of the long chain methylene in SDS into an up-field signal and a down-field signal These concentrations for the splited peak are equial 0 70 and 1 50 mole fraction in the absence of and in the presence of PVP, respectively But for the cationic surfactant DTAB（dodecyl-trimethylammonium bromide）and the zwitterionic surfactant C₁₂BE（dodecylbetaine）, the solubilization location and amount are not affected by PVP The above-mentioned results are also discussed theoretically in this paper It is believed to be practically important in formulation of the detergents and cosmetics