Self-Assembly and Hierarchies in Pyridine-Containing Homopolymers and Block Copolymers with Hydrogen-Bonded Cholesteric Side-Chains
Self-Assembly and Hierarchies in Pyridine-Containing Homopolymers and Block Copolymers with Hydrogen-Bonded Cholesteric Side-Chains
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DOI：
10.1021/ma9021604
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发表时间：
2010-01
期刊：
影响因子：
5.5
通讯作者：
Juuso T. Korhonen;Tuukka Verho;P. Rannou;O. Ikkala
中科院分区：
文献类型：
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作者：
Juuso T. Korhonen;Tuukka Verho;P. Rannou;O. Ikkala
我们研究超分子复合物中的介晶分子，胆固醇半琥珀酸酯（CholHS），是氢键的均聚物，聚（4-乙烯基吡啶）（P4 VP），使液晶和嵌段共聚物聚苯乙烯-嵌段-聚（4-乙烯基吡啶）（PS-b-P4 VP），允许分级自组装。P4 VP和CholHS的共混物（具有一个或更少的CholHS分子相对于每个吡啶基团）形成微相分离的近晶A（SmA）结构，其中周期对应于介晶的头对头排列，基于小角X射线散射（SAXS）、偏光显微镜（POM），如差示扫描量热法（DSC）所支持的。加热导致各向同性熔体。液晶性在低程度的CholHS络合时是最稳定的，而在高程度的络合时，由于CholHS结晶可能会发生竞争效应，这取决于热历史。当CholHS与PS-b-P4 VP复合时，分级结构中的结构形态被破坏。
We investigate supramolecular complexes where a mesogenic molecule, cholesteryl hemisuccinate (CholHS), is hydrogen-bonded to a homopolymer, poly(4-vinylpyridine) (P4VP), to allow liquid crystallinity and to block copolymer polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP), to allow hierarchical self-assembly. Blends of P4VP and CholHS (with one or less CholHS molecules vs each pyridine group) form microphase separated smectic A (SmA) structures where the periods correspond to a head-to-head arrangement of the mesogens, based on small angle X-ray scattering (SAXS), polarized optical microscopy (POM), as supported by differential scanning calorimetry (DSC). Heating leads to an isotropic melt. Liquid crystallinity is most stable at low degrees of CholHS complexation, whereas at high degrees of complexation competing effects due to CholHS crystallization may take place, depending on the thermal history. When CholHS is complexed with PS-b-P4VP, hierarchical structure-within-structure morphologies are observ...