Uniaxial–Biaxial Nematic Phase Transition in Combined Main-Chain/Side-Chain Liquid Crystal Polymers Using Self-Consistent Field Theory
Uniaxial–Biaxial Nematic Phase Transition in Combined Main-Chain/Side-Chain Liquid Crystal Polymers Using Self-Consistent Field Theory
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DOI：
10.1021/ma2027879
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发表时间：
2012-04
期刊：
影响因子：
5.5
通讯作者：
Guang Yang;P. Tang;Yuliang Yang
中科院分区：
文献类型：
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作者：
Guang Yang;P. Tang;Yuliang Yang
采用拟谱方法数值求解半柔性链自洽场方程，研究了主链/侧链组合液晶聚合物（MCSCLCP）的各向同性-各向异性相变和构象.涉及两种相互作用：骨架片段之间、骨架和侧基之间、侧液晶基之间的全局耦合以及聚合物骨架及其所附侧基之间的局部耦合。当铰链是灵活的，无论是全球和本地的影响，更喜欢平行对齐的骨干和侧基，形成只有长轴单轴双相NPIII。当铰链相对较硬时，由于梳状结构，系统的平行取向的全局相互作用与两个组分的垂直取向之间的竞争导致了具有各种取向模式的丰富相，包括单轴长轴相NPI，NPII，和扁圆相NO和双轴长轴相NO。
We investigate the isotropic–anisotropic phase transitions and the conformation of combined main-chain/side-chain liquid crystal polymers (MCSCLCPs) by numerically solving semiflexible chain self-consistent field theory (SCFT) equations with the pseudospectral method. Two kinds of interactions are involved: the global coupling between backbone segments, between the backbone and side groups, and between the side mesogens and the local coupling between the polymer backbone and its attached side groups. When the hinges are flexible, both global and local effects prefer parallel alignments of backbone and side groups, forming only prolate uniaxial nematic phase NPIII. When the hinges are relatively stiff, the competition between the global interaction preferring parallel orientations of the system and the perpendicular tendency of the two components due to the comb architecture results in rich phases with various orientation modes, including uniaxial prolate phases NPI, NPII, and oblate phase NO and biaxial p...