Synthesis and Self-Assembly of Silicon-Containing Azobenzene Liquid Crystalline Block Copolymers
Synthesis and Self-Assembly of Silicon-Containing Azobenzene Liquid Crystalline Block Copolymers
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DOI：
10.1021/acs.macromol.2c02343
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发表时间：
2023-01
期刊：
影响因子：
5.5
通讯作者：
Lin Weng;Mingchao Ma;Chenxiao Yin;Zhixiong Fei;Ke-Ke Yang-Ke;C. Ross;Lingying Shi
中科院分区：
文献类型：
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作者：
Lin Weng;Mingchao Ma;Chenxiao Yin;Zhixiong Fei;Ke-Ke Yang-Ke;C. Ross;Lingying Shi
报道了一种高相互作用参数的含硅液晶嵌段共聚物（Si-LCBCP）的合成和自组装，其侧链中含有热响应和光响应的偶氮苯介生，这些介生发生分子结构转变，影响嵌段共聚物的相变和取向。采用原子转移自由基聚合的方法合成了一系列含偶氮苯的Si-LCBCPs聚{二甲基硅氧烷-b-11-[4-（4-氰苯偶氮）苯氧基]十一烷甲基丙烯酸酯}，并描述了LC嵌段的本体自组装以及液晶（LC）相变对bcbps微相分离纳米结构的影响。当PMAAzo块体（fPMAAzo）的体积分数从41%变化到71%时，得到了片层状、双陀螺状（GYR）、正交fdddnetwork、六边形填充柱状（HEX）和体心立方状纳米结构。当fpmaazo = 55-57%时，观察到温度变化和LC相变诱导的热可逆hex - gyr - fddd相变。体形态与薄膜自组装相比较，并证明了模式转移到二氧化硅纳米结构。
The synthesis and self-assembly of a high interaction parameter silicon-containing liquid crystalline block copolymer (Si-LCBCP) are reported, containing thermally and photo-responsive azobenzene mesogens in the side chains which undergo molecular structural transitions, influencing phase transitions and orientation in the block copolymer. A series of the azobenzene-containing Si-LCBCPs, poly{dimethylsiloxane-b-11-[4-(4-cyanophenylazo)phenoxy]undecane methacrylate}, were synthesized through atom transfer radical polymerization, and the bulk self-assembly as well as the influence of the liquid-crystalline (LC) phase transition of the LC block on the microphase-separated nanostructure of the BCPs is described. As the volume fraction of the PMAAzo block (fPMAAzo) changes from 41 to 71%, lamellar, double gyroid (GYR), orthorhombicFdddnetwork, hexagonally packed cylindrical (HEX), and body centered cubic nanostructures were obtained. WhenfPMAAzo= 55–57%, a thermally reversible HEX-GYR-Fdddphase transition induced by the temperature change and LC phase transition was observed. Bulk morphologies are compared with thin-film self-assembly, and pattern transfer into silica nanostructures is demonstrated.