PHOTOORIENTATION IN LB MULTILAYERS OF AMPHOTROPIC POLYMERS

Amphotropic polymers with photochromic azobenzene side groups like 2-h ydroxyethyl polyacrylates and ''hairy rod'' polyglutamates combine amp hiphilic and thermotropic properties. Upon UV irradiation the initial double layer structures were irreversibly destroyed by the E-Z photois omerization. New ordered structures with modified spacing, in-plane an isotropy and surface topology were generated by a subsequent Vis irrad iation step. Optical anisotropy was modified due to a photo-orientatio n process on irradiation with linearly polarized Vis light. Relations between photoinduced modification and thermotropic self-organization a re demonstrated for Langmuir-Blodgett (LB) layers of both types of pol ymers. The dependence of the photoinduced reorientation process on the structure, supermolecular order and the aggregation of the azobenzene moieties is shown for the different ordered LB systems.