| The arrangement of liquid crystal (LC) change easily when the electric field or thermal field added. Accompaning this, some kinds of LC molecules optical properties, such as birefringence, polarization, optically scatter etc. change also. The alignment of liquid crystal molecules on a treated substrate surface is important and necessary not only for preparing liquid crystal devices (LCD), but for the investigation of the physical properties of liquid crystals. At present. the most of LC alignments are based on the surface orientation of liquid crystal by rubbed polymers. However, the rubbing technique is known to have several shortcomings for mass-production of LCDs such as the generation of electrostatics charges. dust particles or mechanical defects, which reduce production yield, especially of active matrix LCDs during the rubbing process. The more salient is that the narrow. non-uniform viewing angle problem, which was induced by the uniaxial characteristics of liquid crystal gras difficult to be solved by rubbing technique. Recently. photo-alignment technology is useful for LCD manufacturing because it allows for the non-contact alignment of LC which eliminates the problems associated with mechanical rubbing such as the generation of dust and static electricity. And it can also realize multi-domain technique which easily carry out wide viewing angle of LCDs. Anisotropic surface tension caused by?linearly polvmerized reaction of photo-sensitive precursor can induce LC molecule align. Photo-alignment technique is a perfect and without negative effect alignment method in theory. However, the orientation order of 3 photo-alignment layers is still not good enough to induce LC align better. A novel method to form high qualified LC photo-alignment layer was proposed and was investigated in this paper. The alignment characteristics of liquid crystals on the various photosensitive polymerized film surfaces were studied with using polarized micrography. It was shown that the thermal stability of LC molecules orientation induced by alignment layers containing cinnamate group is lower. There have mass disclinations when it was heated 30 minutes at 800C~ The photochemical efficiency of the pre-polymers containing coumarin group is lower. on which film the LC alicnment was just able to appear when it was exposed by UV light for 600 minutes. The photosensitive poly-acid PAA(BTDA-TMMDA) provides higher photo chemical efficiency. About 64% of pre-polymer molecules were participated in photo chemical reaction after exposed of UV light for 15 minutes. However, the orientation order of alignment layers made of above three polymers are not high enough to induce LC align better. A novel method using small size molecule to form anisotropic LC alignment layers with exposing to linearl~?UV light which can increase alignment layer orientation order was proposed. Rigid rod-shaped small size molecule was selected as photosensitive precursor. For the reason that the size of small molecule is more shorter than gigantic molecules, it shows less spacial resistance and high reaction efficiency. And the orientation order brought from small molecules linearly polymerization is evidently higher than gigantic molecule photo cross-linkinc. The polarized Fourier transformation Infrared absorption spectra (FT-IR) was used in this paper to measure the orientation order of photo-...
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