Competition of self-organization and photoorientation in liquid crystalline polymers

Photoreorientation processes in photochromic LCP's are dependent on the supramolecular order. The efficiency is much higher in films of low order, which have been obtained by a suitable preparation or by an intermediate photochemical decoupling. On the other hand, a photochemically induced order in an initially isotropic film acts as initializing force, governing the direction of thermotropic self-organization. The combination of both ordering principles causes a significant amplification of the light-induced optical anisotropy.