초록 |
A series of polystyrene (PS) derivatives were synthesized using polymer analogous reactions to investigate liquid crystal (LC) alignment property of these polymer films. The LC alignment director for films of PS derivatives containing coumarin side groups was found to be perpendicular to the rubbing direction. The contrast ratio and azimuthal anchoring energy values of these PS derivatives were found to be much greater than those of PS, indicating that the coumarin side groups increase aligning ability. LC cells fabricated with 2-naphthoxymethyl-substituted PS films exhibited a homeotropic LC alignment behavior. LC cells fabricated using the films of the n-alkylthiomethyl-substituted PS and n-alkylsulfonylmethyl-substituted PS having longer, higher molar content of n-alkyl side group, and thioether linkage group showed a homeotropic LC alignment behavior. The homeotropic alignment behavior was correlated with the surface energy of the polymer films very well. |