Ordered nanostructures at two different length scales mediated by temperature: A triphenylene‐containing mesogen‐jacketed liquid crystalline polymer with a long spacer
Ordered nanostructures at two different length scales mediated by temperature: A triphenylene‐containing mesogen‐jacketed liquid crystalline polymer with a long spacer
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DOI：
10.1002/pola.27003
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发表时间：
2014-02
期刊：
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通讯作者：
Yu-feng Zhu;Hai-jian Tian;Honglian Wu;De-Zhao Hao;Yu Zhou;Zhihao Shen;Dechun Zou;P. Sun;Xinghe Fan;Qifeng Zhou
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文献类型：
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作者：
Yu-feng Zhu;Hai-jian Tian;Honglian Wu;De-Zhao Hao;Yu Zhou;Zhihao Shen;Dechun Zou;P. Sun;Xinghe Fan;Qifeng Zhou
合成了一种侧链中含有三苯基（Tp）的介质夹套液晶聚合物（MJLCP）， 12个亚甲基为间隔单元（记为PP12V）。采用溶液1H NMR、固态NMR、凝胶渗透色谱、热重分析、偏振光显微镜、差示扫描量热法、一维和二维广角x射线衍射等手段对其液晶相行为进行了研究。通过简单地改变温度，在一种聚合物中获得了两个亚10nm长度尺度的有序纳米结构。低温相为六方柱状相（ΦH, a = 2.06 nm），由Tp盘状介质自组织。高温相为大尺寸的向列柱状相（a′= 4.07 nm），由棒状超分子介原- MJLCP链整体形成。在中温范围内发现了一个可重入的各向同性相。当电场处理时，聚合物的部分同向取向可以实现，聚合物在ΦH相中由Tp部分发展。Tp部分通过相对较长的间隔（12个亚甲基单位）的结合，在低温下破坏了MJLCP的有序包装，这是我们所知的第一个以MJLCP作为主链LC构建块的主链/侧链结合LC聚合物。PP12V的分子结构与新相行为的关系对设计含纳米构建块的LC聚合物以构建不同长度尺度的有序纳米结构具有指导意义。©2013 Wiley期刊公司j .变异较大。科学。A部分：Polym。化学，2014,52,295-304
A mesogen-jacketed liquid crystalline polymer (MJLCP) containing triphenylene (Tp) moieties in the side chains with 12 methylene units as spacers (denoted as PP12V) was synthesized. Its liquid crystalline (LC) phase behavior was studied with a combination of solution 1H NMR, solid-state NMR, gel permeation chromatography, thermogravimetric analysis, polarized light microscopy, differential scanning calorimetry, and one- and two-dimensional wide-angle X-ray diffraction. By simply varying the temperature, two ordered nanostructures at sub-10-nm length scales originating from two LC building blocks were obtained in one polymer. The low-temperature phase of the polymer is a hexagonal columnar phase (ΦH, a = 2.06 nm) self-organized by Tp discotic mesogens. The high-temperature phase is a nematic columnar phase with a larger dimension (a′ = 4.07 nm) developed by the rod-like supramolecular mesogen—the MJLCP chain as a whole. A re-entrant isotropic phase is found in the medium temperature range. Partially homeotropic alignment of the polymer can be achieved when treated with an electric field, with the polymer in the ΦH phase developed by the Tp moieties. The incorporation of Tp moieties through relatively long spacers (12 methylene units) disrupts the ordered packing of the MJLCP at low temperatures, which is the first case for main-chain/side-chain combined LC polymers with MJLCPs as the main-chain LC building block to the best of our knowledge. The relationship of the molecular structure and the novel phase behavior of PP12V has implications in the design of LC polymers containing nanobuilding blocks toward constructing ordered nanostructures at different length scales. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 295–304