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Liquid‐crystal alignment on rubbed polyimide films with various side chains
Author(s) -
Kim S. I.,
Shin T. J.,
Ree M.,
Jung J. C.
Publication year - 2000
Publication title -
journal of the society for information display
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 52
eISSN - 1938-3657
pISSN - 1071-0922
DOI - 10.1889/1.1828703
Subject(s) - rubbing , mesogen , side chain , polyimide , liquid crystal , biphenyl , materials science , molecule , alkyl , polymer chemistry , crystallography , polymer , liquid crystalline , organic chemistry , chemistry , composite material , layer (electronics) , optoelectronics
— A series of polyimides containing various side chains was synthesized in order to investigate the effect of side chains on the alignment of liquid crystals on the rubbed surface. Here, the side chains include short flexible alkyl spacers and isomeric biphenyl mesogens. The pretilting of liquid‐crystal (LC) molecules was found to be very sensitive to the isomeric structure of biphenyl mesogen end groups as well as the conformation and length of flexible spacers, in addition to the rubbing process. The pretilt angle of LC molecules in the LC cell was achieved in a wide angle range of 8–27°, depending upon the rubbing density as well as the side chains. The high performance in the pretilt and alignment of LCs might be attributed mainly to a strong interaction between the biphenyl mesogen end group in the side chain and the LC molecule in addition to the microgrooves generated in the rubbing direction.