Smectic Surface-Structures in the Isotropic-Phase of Liquid-Crystalline Polymers Studied by X-Ray Reflectivity

Abstract

In an X-ray reflectivity study of thin films of several liquid crystal-side group polymers, boundary layers with a smectic structure were detected in the isotropic phase. They possess a remarkable stability and exist also at larger distances from the clearing point. Reflectivity curves were evaluated in detail by application of the Born approximation on a convenient structure model of the film. A stepwise procedure for the data evaluation is suggested, which enables a separate determination for different groups of model parameters.