Liquid Crystal Alignment on Rubbed Polyvinyl- Cinnamate with Overdose of UV Light

• Published in: Journal of Photopolymer Science and Technology Vol. 20; no. 1; pp. 23 - 27
• Main Authors: Yamaguchi, Rumiko, Kimura, Junji, Sato, Susumu
• Format: Journal Article
• Language: English
• Published: Hiratsuka The Society of Photopolymer Science and Technology(SPST) 2007; Japan Science and Technology Agency
• Subjects: Alignment; Anchoring Energy; Crosslikable Polymer; Dosage; Lamps; Liquid Crystal; Liquid crystals; Mercury; Optical Erasing; Optical properties; Optical Writing; Orientation; Photoalignment; Twisted Nematic
• ISSN: 0914-9244; 1349-6336; 1349-6336
• DOI: 10.2494/photopolymer.20.23

Liquid crystal (LC) alignment properties and the optical writing and erasing have been reported in the LC cell with rubbed Polyvinyl-Cinnamate (PVCi) alignment film. The azimuthal anchoring energy of the PVCi surface increased by the UV light exposure. The optical writing of twisted nematic (TN) orientation domains was demonstrated on the homogeneous orientation background in the LC cell with the UV dosage less than 2 J/cm2 from a super high pressure Hg lamp. The TN orientation changed to the homogeneous orientation again with the overdose of the UV light and the written image erased, if the LC material with the UV absorption around 313 nm of the line spectrum of the Hg lamp was used. On the other hand, when the LC without the UV light absorption was used, the LC alignment did not change and the written image was kept with the UV dosage more than 30 J/cm2.