LANGMUIR-BLODGETT-FILM OF A NEW FLUORINATED POLYPHILIC COMPOUND

Polyphilic surfactants made up of a carboxylic hydrophilic headgroup, a biphenyl rigid core, a flexible hydrocarbon spacer, and a perfluorin ated chain are used to build Langmuir-Blodgett multilayers. The films are investigated by X-ray reflectivity, infrared dichroism, and scanni ng electron microscopy. At the transfer pressure used, the molecular a rea is consistent only with molecular long axes orthogonal to the air- water interface. Such a situation is retained for the first transferre d monolayer whose thickness is equal to the molecular length in the fu lly elongated conformation, For thick films however, molecular long ax es are tilted toward the dipping direction. Such a finding involves a rearrangement which does not retain the total number of layers.