| 초록 |
We prepared the blend alignment layers made from polymethacrylate with coumarin side chains and polyimides for liquid crystal(LC) alignment using linearly polarized ultraviolet(UV) exposure. We used two different polyimides such as 4,4’-(hexafluoro-isopropylidene) diphthalic anhydride-3,5-diamino-benzoic acid(6FDA-DBA) and pyromellitic dianhydride-4,4’-oxydiamiline(PMDA-ODA) and the alignment properties of LC were found to depend on the type of polyimide in the blend alignment layers. Thermal stability of LC alignment was enhanced regardless of the type of polyimides, whereas the LC alignment direction was different for each type of polyimide. The degree of photereaction of polyimide was important factor for LC alignment direction on the blend alignment layers and this seems to be attributed to the different LC alignment direction for polymethacrylate with coumarin and polyimides. We could change the LC alignment directions by controlling the photoreaction of polyimides using the proper filters for polarized UV exposure. |
