Bilayer Membranes of Triple-Chain, Fluorocarbon Amphiphiles

Triple-chain ammonium amphiphiles were prepared in which one, two, or three fluorocarbon chains are present. They formed clear aqueous dispersions upon sonication. Electron microscopy indicated the formation of bilayer vesicles. Differential scanning calorimetry (DSC) and fluorescence depolarization experiments (probes: Anilinonaphthalenesulfonate and di-phenylhexatriene) established the presence of crystal-to-liquid crystal transitions in all cases: 36–54 °C. The fluidity of the liquid-crystalline bilayers near the membrane surface increased with increasing numbers of the fluorocarbon tail, whereas that of the bulk membrane decreased with increasing fluorocarbon tails. Mixing behavior of bilayers was examined by DSC. The totally fluorocarbon-tailed bilayer did not readily mix with totally or partially hydrocarbon-tailed bilayers. In contrast, the totally hydrocarbon-tailed bilayer mixed more readily with partially fluorocarbon-tailed bilayers. Finally, the use of the present bilayer system for constructing complex molecular assemblies was discussed.