LIANG Zhaoyan, YAN Shi, MA Kai, HUANG Ximin, XIE Jingli, ZHANG Yanjie, TIAN Yanqing, ZHAO Yingying, ZHANG Jinbao. STUDY ON PHOTO ALIGNMENT OF CINNAMATE MATERIAL 2-(CINNAMOYLOXY)ETHYL METHACRYLATE FOR LCD USING LPP METHOD BY UV-LIGHT[J]. Chinese Journal of Luminescence, 1999,20(3): 217-223
LIANG Zhaoyan, YAN Shi, MA Kai, HUANG Ximin, XIE Jingli, ZHANG Yanjie, TIAN Yanqing, ZHAO Yingying, ZHANG Jinbao. STUDY ON PHOTO ALIGNMENT OF CINNAMATE MATERIAL 2-(CINNAMOYLOXY)ETHYL METHACRYLATE FOR LCD USING LPP METHOD BY UV-LIGHT[J]. Chinese Journal of Luminescence, 1999,20(3): 217-223DOI:
Surface alignment of liquid crystals(LCs)on treated polymer substrates is one of key technologies to fabricate liquid crystal displays(LCDs)and thus many works on this subject have been done.Recent process of photo-alignment control of LC molecules on photopolymer film was considered the photo-alignment technique is a hopeful candidate for rubbing-free technique.The process of photochemical reaction of Cinnamate material 2-(cinnamoyloxy)ethyl methacrylate(CEMC)using LPP(linear polarized photopolymerization)method by UV-light was studied in this paper.We also investigated the effect of the CEMC aligning on liquid crystal LC-6710A molecules.The liquid crystal molecules alignment was more homogeneous when the photosensitive IRG184 was taken a part into pre-polymer CEMC mixture.The photochemical reaction probability was increased because of the energy transfer between photosensitive IRG184 and pre-photopolymer CEMC molecules.The change of alignment substrate surface
which was shown less difference on the micrography of substrate surface was observed before and after photochemical reaction by Atomic Force Microscopy(AFM).The pretilt angle 0.7 degree of LC molecules on photo-alignment substrate surface was measured.The electro-optical property and time response curves of twisted nematic liquid crystal display(TNLCD)with single side photo-alignment substrate were obtained.It is shown that the properties curves of TNLCD with single side photo-alignment substrate and conventional TNLCD were similar.The mechanism of liquid crystal molecule alignment on photo-alignment substrate surface was discussed.We consider that the liquid crystal molecules alignment was not ascribed to the grooves on the substrate surface
but was ascribed to the interaction between liquid crystal molecules and photopolymer molecules on substrate surface.The photopolymer material CEMC is feasible for LCD fabrication.