Micellization of fluorinated amphiphiles

New cationic fluorinated surfactants and new types of fluorinated surfactants having fluorocarbon-hydrocarbon hybrids, dimeric and polymeric structure have been synthesized recently. Their synthesis requires many steps and consequently requires much time and high expense. Since the fluorinated surfactants have unusual molecular aggregation properties, F-19-NMR, novel fluorescence probes and cryo-transmission electron microscope techniques have been applied to study their aggregation behaviour in aqueous systems. Their unique characteristics are summarized as follows: (1) the dissolution process from solid state to dissolved aggregate state requires a very long time for the long chain fluorinated surfactants under thermodynamic equilibrium. The equilibration time can be reduced at higher temperatures; (2) interfacial properties and critical micelle concentration (CMC) are influenced by the nature of the hydrophobic terminal groups (CF3 - or H-CF2 -); (3) the fluorocarbon functionality can make it possible even for single-chain amphiphiles to form vesicles or lamellar structures; (4) the hybrid surfactant made of both hydrocarbon and fluorocarbon chains showed a life time of 2.0 x 10(-3) s for the exchange rate between the monomeric and the micellar states at the CMC and moreover, these detergents can cosolubilize fluorocarbon-hydrocarbon mixed solubilizates. (C) 2003 Elsevier Ltd. All rights reserved.