Organometallic amphiphiles are new class of surfactants. Various novel chemical and physical properties of their aggregates, such as selective binding to metal ions, active control of interfacial tension, catalytic behavior and charge transfer, have been widely investigated in recent years. These interesting properties are reviewed in this paper.

Spontaneous vesicle formation was observed in aqueous mixtures of partially hydrolyzed polyacrylamide and single-tailed cationic surfactants. The influences of pH, addition of long-chain alcohols, variation of hydrocarbon chain length, and head group size of the cationic surfactants were investigated systematically. It was found that 30-50% hydrolyzed degree of polyacrylamide and cationic surfactants with 10 or 12 methylene groups are suitable for vesicle formation in the mixed aqueous systems at pH 9.2. Addition of long-chain alcohols was found to be helpful for vesicle formation in some cases. The vesicle stability was also investigated at various temperatures and amounts of ethanol addition.

Anamino acid amphiphile, N-(4-decyloxy-2-hydroxybenzylidene) glycine, wassynthesized. Surface tension measurement, dynamic light scattering, and transmission electron microscopy were used to investigate its surface activity and aggregation in solution. All behavior was sensitive to the pH value of the solution. It was found that these properties occur at pH=12, which is different from the usual situation for carboxylate amphiphiles. The abnormal behavior can be attributed to the formation of a dimeric structure at pH=12.0. Vesicles were found in this kind of system, which are stable even at the concentration of transition metal ions up to 1mM. This phenomenon was attributed to the formation of complexes.

The transition from vesicles to micelles by adding octane into the dodecyl-pyridinium chloride (DPCl)/sodium laurate (SL), and dodecyltrimethylammonium bromide (DTAB)/SL aqueous two-phase systems has been studied. The two-phase systems were transformed into single-phase isotropic solutions with the addition of a certain amount of octane. The results of dynamic light scattering (DLS) demonstrate the decrease of large aggregates (vesicles) and the increase of the small aggregates (spherical micelles) upon octane addition. Such transformation of the surfactant aggregates was also corroborated by the results of time-resolved fluorescence quenching (TRFQ) and viscometry. The change of the phase behavior was discussed on the basis of the interaggregate interactions influenced by the variation of organized assemblies.