MONODISPERSE PERFLUOROALKYL OXYETHYLENE NONIONIC SURFACTANTS WITH METHOXY CAPPING - SYNTHESIS AND PHASE-BEHAVIOR OF WATER SURFACTANT BINARY-SYSTEMS

New monodisperse surfactant molecules with a poly(oxyethylene) methoxy -capped chain for the hydrophilic head and a perfluoroalkyl moiety for the hydrophobic tail are synthesized. The principle of solid-liquid p hase transfer reactions is used. Surface tension measurements of aqueo us solutions (gamma approximately 20 mN m-1) show slow organization of the surfactant film at the water/air interface for the fluorocarbon t ail. Values of the critical concentration and comparisons with the hyd roxy-capped analogous surfactants are consistent with a small influenc e of the hydrophobic effect of the methoxy terminal group on the polar head. The results of phase behavior in aqueous binary systems are dis cussed. As expected, the replacement of OH group by an OMe group effec tively reduces the hydrophilicity of the surfactant but does not chang e dramatically its phase behavior in water.