Association Behavior and Ordered Nanoaggregation of Charged Fullerene Derivatives and Cationic Surfactants in Solution

Abstract

The complexation between fullerene hexamalonate anions (FHM-) and dodecyl- (DP+) and cetylpyridinium (CP+) cations was studied in aqueous solutions in the absence and in the presence of NaCl by potentiometric and fluorimetric measurements. Results demonstrated a high association tendency between FHM- and cationic surfactants in aqueous solution, with characteristics similar to those found in complexes of linear polyelectrolytes with surfactants. It is proposed that FHM- spheres gradually arrange themselves into agglomerates of binding sites in conjunction with surfactant. SAXS studies on precipitated, wet surfactant/FHM- complexes suggest the formation of highly ordered lamellar and hexagonally packed cylinder structures.