1H NMR and 31P NMR Investigation of Mixed Surfactants of Lecithin with Nonionic and Ionic Surfactants

Interaction of lecithin with nonionic surfactants belonging to Tween series, anionic surfactant SDBS and cationic surfactant chirrasol during mixed micellization has been studied using ¹H NMR and ³¹P NMR spectroscopy. It has been shown that the addition of nonionic surfactant transforms the vesicle of lecithin into mixed micelles. the spectral evidence indicates that the interaction is hydrophilic-hydrophilic. In case of lecithin-anionic surfactant, the interaction is found to be rather weak, whereas in case of lecithin-cationic surfactant, the interaction is practically absent.