title: On the surface properties of oleate micelles and oleic acid/oleate vesicles studied by spin labeling.
abstract: Dilute aqueous systems composed of sodium oleate micelles and sodium oleate/oleic acid vesicles were investigated as a function of pH by electron spin resonance spectroscopy with TEMPO-stearate TEMPO-stearamide as well as with a positively charged water soluble spin label, TEMPO-choline. The dynamics of the three TEMPO-spin labels were found to be sensitive to changes in the interfacial region of the aggregates as a function of pH. The results obtained are consistent with the formation of a hydrogen bond network (RCOO(-)↔HOOCR) at the surface of the sodium oleate/oleic acid system in the course of the transformation of micelles into the closed bilayers (vesicles). Vesicles formation below pH 10 was determined independently with a spin labeled glucose derivative.
authors.affiliation: Department of Physical Chemistry, "Ruđer Bošković" Institute, 10002 Zagreb, Croatia.
authors.forename: Branka
authors.initials: B
authors.lastname: Dejanović
authors.forename: Vesna
authors.initials: V
authors.lastname: Noethig-Laslo
authors.forename: Marjeta
authors.initials: M
authors.lastname: Sentjurc
authors.forename: Peter
authors.initials: P
authors.lastname: Walde
mesh_terms: D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006860:Hydrogen Bonding; D008823:Micelles; D019301:Oleic Acid / Q000737:chemistry*; D013113:Spin Labels; D013499:Surface Properties
chemical_list: D008823:Micelles; D013113:Spin Labels; D019301:Oleic Acid; C013173:osteum