Thermal and Photochemical Control of Molecular Orientation of Azo-Functionalized Polymer Liquid Crystals and Application for Photo-Rewritable Paper
✍ Scribed by Masaki Moritsugu; Takeru Ishikawa; Tetsuro Kawata; Tomonari Ogata; Yutaka Kuwahara; Seiji Kurihara
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 392 KB
- Volume
- 32
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
Abstract
A photo‐responsive multi‐bilayered film consisting of azobenzene polymer liquid crystals (PA6Az1) and poly(vinyl alcohol) (PVA) has been prepared on a glass substrate by alternate spin coating of the polymer solutions. The reflectivity of the multi‐bilayered film disappears by annealing at 80 °C. The disappearance of the reflection by the annealing is related to the thermal out‐of‐plane molecular orientation of PA6Az1 even in the multi‐bilayered film, which leads to a very small difference in refractive indices between PA6Az1 and PVA. The reflectance of the multi‐bilayered film is increased again by UV irradiation because of the transformation from the out‐of‐plane orientation to an in‐plane random orientation. In this way, on–off switching of the reflection is achieved by combination of the thermally spontaneous out‐of‐plane molecular orientation and following photoisomerization of PA6Az1 comprising the multi‐bilayered film.
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