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Enhanced, Perpendicular Liquid-Crystal Alignment on Rubbed Films of a Coumarin-Containing Polystyrene

✍ Scribed by Hyo Kang; Ki-Sun Kwon; Daeseung Kang; Jong-Chan Lee

Book ID
102483779
Publisher
John Wiley and Sons
Year
2007
Tongue
English
Weight
197 KB
Volume
208
Category
Article
ISSN
1022-1352

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✦ Synopsis

Abstract

We synthesized a series of polystyrene derivatives containing coumarin side groups using polymer analogous reactions. The liquid‐crystal (LC) alignment director for these polymer films was found to be perpendicular to the rubbing direction. The contrast ratio and anchoring‐energy values of these polystyrene derivatives were found to be much greater than those of polystyrene and poly(chloromethylstyrene), indicating that the coumarin side groups increase the aligning ability. For example, the anchoring energy of a polymer with 82 mol‐% of coumarin‐containing monomeric units, compared to polystyrene, is about 7 × 10^βˆ’5^ J · m^βˆ’2^ and 1 × 10^βˆ’7^ J · m^βˆ’2^, respectively.

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