Physicochemical properties of aqueous mixed solutions of sugar-persubstituted poly(amidoamine)dendrimers and anionic surfactants

Mixed aqueous properties of sugar-persubstituted poly(amidoamine) dendrimers (generation, 3.0 and 5.0) (sugar ball) and anionic surfactants, such as sodium dodecyl sulfate (SDS) and lithium perfluorooctanesulfonate (LiFOS), were investigated. The surface tensions of the mixtures of sugar balls and anionic surfactants at several fixed concentrations of sugar balls decreased sharply at low surfactant concentration, remained constant and then increased with a further increase of the surfactant concentration where the lower the surface tensions, the smaller the fixed concentration of the sugar balls. From the measurements of pyrene and 1-(perfluorooctanoyl)pyrene fluorescence spectra, it is suggested that aggregates between the anionic surfactants and sugar balls are formed, showing a hydrophobic environment. The mechanism for the aggregation formation is discussed.