Photoalignment at the nematic liquid crystal-polymer interface: Experimental evidence of three-dimensional reorientation

Abstract We provide experimental evidence that photoalignment at the nematic liquid crystal (NLC)-polymer interface cannot be simply considered as a two-dimensional process. Moreover, our experiments clearly indicate that the photoaligning process does not depend on the individual properties of the NLC material and those of the interfacing polymer exclusively. The polymer and the NLC layer interact, i.e., the polymer-liquid crystal interface should be regarded as a coupled system, where the two components mutually influence each other. Furthermore, we show that the temperature induced anchoring transition also has to be taken into account for the complete description of the photoalignment mechanism.