Effects of monomer structure on their organization and polymerization in a smectic liquid crystal
Effects of monomer structure on their organization and polymerization in a smectic liquid crystal
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DOI：
10.1126/science.275.5296.57
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发表时间：
1997-01-03
期刊：
影响因子：
56.9
通讯作者：
Bowman, CN
中科院分区：
文献类型：
--
作者：
Guymon, CA;Hoggan, EN;Bowman, CN
光聚合双丙烯酸酯单体在近晶A和近晶C液晶（LC）中表现出明显的空间偏析和取向，这种空间偏析与单体结构密切相关。小而灵活的单体，如1,6-己二醇二丙烯酸酯（HDDA），平行于近晶层并插入，而棒状的中原状单体，如1,4-二(4-（6-丙烯氧基己基氧基）-2-甲苯（C6M），垂直于近晶层并聚集在其中。这种由近晶层造成的空间偏析显著提高了光聚合速率；HDDA的终止率降低，而C6M的终止率和繁殖率均增加。这些聚合前体结构为凝胶lc和纳米相分离聚合物系统提供了新的材料设计范例。
Photopolymerizable diacrylate monomers dissolved in fluid-layer smectic A and smectic C liquid crystal (LC) hosts exhibited significant spatial segregation and orientation that depend strongly on monomer structure. Small, flexible monomers such as 1,6-hexanediol diacrylate (HDDA) oriented parallel to the smectic layers and intercalated, whereas rod-shaped mesogen-like monomers such as 1,4-di-(4-(6-acryloyloxyhexyloxy)ben zoyloxy)-2-methylbenzene (C6M) oriented normal to the smectic layers and collected within them. Such spatial segregation caused by the smectic layering dramatically enhanced photopolymerization rates; for HDDA, termination rates were reduced, whereas for C6M, both the termination and propagation rates were increased. These polymerization precursor structures suggest novel materials-design paradigms for gel LCs and nanophase-separated polymer systems.