VESICLES OF MIXED BICATENARY SURFACE-ACTI VE AGENTS - CHARACTERIZATION AND STABILITY OF THESE ORGANIZED MOLECULAR-SYSTEMS

The aggregation behaviour in water of 16 ammonium amphiphiles containi ng one long perfluoroalkyl tail and one long hydrocarbon tail have bee n studied. Upon sonication, the corresponding vesicular systems were i dentified by freeze fracture electron microscopy. Their size distribut ion and mean diameter were investigated by photon correlation spectros copy (PCS). Long term storage of these systems, showed that their stab ility is a function of the temperature and of the amphiphilic structur e: hydrocarbon chain length and nature of the connector. The crystal t o liquid-crystal transition temperature (T-c) of these systems could n ot be determined by differential scanning calorimetry (DSC) and light scattering experiments.