Authors: Hyo Kang JongChan Lee Daeseung Kang
Publish Date: 2010/03/05
Volume: 18, Issue: 1, Pages: 78-85
Abstract
The liquid crystal LC alignment properties of a series of polystyrene derivatives containing various fluorinated side chain terminal moieties such as 4fluorophenoxymethyl 345trifluorophenoxymethyl pentafluorophenoxymethyl and 4trifluoromethoxyphenoxymethyl groups were investigated These polymers could induce homeotropic and/or homogeneous planar LC alignment on their surfaces by changing the LC molecules and rubbing conditions For example when a positive MJ001929 from Merck and negative dielectric anisotropic LC mixture MLC7026000 from Merck were used homeotropic LC alignment was observed in the LC cells made from unrubbed films of pentafluorophenoxymethyl and 4trifluoromethoxyphenoxymethylsubstituted polystyrenes with a smaller surface energy whereas random planar LC alignment was observed in those made from the other polymers with a larger surface energy On the other hand homeotropic LC alignment behavior was observed in all the LC cells made from unrubbed films of all the polystyrene derivatives when 5CB was used as the LC material
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