NMR Study of the Association of Anionic Surfactants with an Anionic Polyelectrolyte Hydrophobically Modified with Perfluorinated Side Chains

Mixtures of surfactants with a hydrophobically modified polyelectrolyte in aqueous solution are investigated by 19 F NMR spectroscopy performed on the fluorinated side chains of the polyelectrolyte component. The two added surfactants, one hydrogenated and one fluorinated, behave differently as manifested by the chemical shift effects in the obtained NMR spectra: the mixing of the hydrogenated one with the polyelectrolyte is clearly nonideal, while the mixing of the two fluorinated species is closer to ideal. The different aggregates dominated either by the polyelectrolyte or by the surfactant component share some dynamic features: the exchange of the polyelectrolyte molecules among them is slow, while that of the surfactant molecules is fast on the millisecond time scale.