Liquid crystal alignment properties of polystyrene derivatives containing fluorinated side groups
Liquid crystal alignment properties of polystyrene derivatives containing fluorinated side groups
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DOI：
10.1007/s13233-009-0149-1
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发表时间：
2010-03
影响因子：
2.4
通讯作者：
Hyo Kang;Jong‐Chan Lee;D. Kang
中科院分区：
文献类型：
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作者：
Hyo Kang;Jong‐Chan Lee;D. Kang
研究了含4-氟苯氧甲基、3,4,5-三氟苯氧甲基、五氟苯氧甲基和4-三氟甲氧基苯氧甲基等不同侧链末端氟化基团的聚苯乙烯衍生物的液晶取向特性。这些聚合物可以通过改变LC分子和摩擦条件在其表面诱导各向同性和/或均匀的平面LC排列。例如，当使用正电各向异性（Merck公司的MJ001929）和负电各向异性LC混合物（Merck公司的MLC-7026-000）时，在由表面能较小的五氟苯氧甲基和4-三氟甲氧基苯氧甲基取代聚苯乙烯制成的未摩擦薄膜制成的LC细胞中观察到各向异性LC排列，而在由表面能较大的其他聚合物制成的LC细胞中观察到随机的平面LC排列。另一方面，当使用5CB作为LC材料时，用所有聚苯乙烯衍生物的未摩擦薄膜制成的LC细胞均具有同向取向行为。
The liquid crystal (LC) alignment properties of a series of polystyrene derivatives containing various fluorinated side chain terminal moieties, such as 4-fluorophenoxymethyl, 3,4,5-trifluorophenoxymethyl, pentafluorophenoxymethyl, and 4-trifluoromethoxyphenoxymethyl 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 (MLC-7026-000 from Merck) were used, homeotropic LC alignment was observed in the LC cells made from unrubbed films of pentafluorophenoxymethyl- and 4-trifluoromethoxyphenoxymethyl-substituted 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.