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    徐敏, 李庆祥, 陆学民, 路庆华. 嵌段质量分数对手性超分子螺旋结构自组装的影响[J]. 功能高分子学报, 2019, 32(3): 300-306. doi: 10.14133/j.cnki.1008-9357.20181008001
    引用本文: 徐敏, 李庆祥, 陆学民, 路庆华. 嵌段质量分数对手性超分子螺旋结构自组装的影响[J]. 功能高分子学报, 2019, 32(3): 300-306. doi: 10.14133/j.cnki.1008-9357.20181008001
    XU Min, LI Qingxiang, LU Xuemin, LU Qinghua. Effect of Mass Fraction of Block Copolymers' Segment on Supramolecular Self-assembly for Chiral Helical Structure[J]. Journal of Functional Polymers, 2019, 32(3): 300-306. doi: 10.14133/j.cnki.1008-9357.20181008001
    Citation: XU Min, LI Qingxiang, LU Xuemin, LU Qinghua. Effect of Mass Fraction of Block Copolymers' Segment on Supramolecular Self-assembly for Chiral Helical Structure[J]. Journal of Functional Polymers, 2019, 32(3): 300-306. doi: 10.14133/j.cnki.1008-9357.20181008001

    嵌段质量分数对手性超分子螺旋结构自组装的影响

    Effect of Mass Fraction of Block Copolymers' Segment on Supramolecular Self-assembly for Chiral Helical Structure

    • 摘要: 首先,以溴代聚乙二醇单甲醚(PEO-Br)为引发剂、甲基丙烯酸丁酯(BMA)为单体,通过原子转移自由基聚合(ATRP)制备了一系列具有不同聚乙二醇(PEO)质量分数的聚甲基丙烯酸丁酯-b-聚乙二醇嵌段共聚物(PBMA-b-PEO)。在此基础上,将手性酒石酸(TA)以氢键的方式选择性掺入到嵌段共聚物的PEO相中,诱导嵌段共聚物自组装制备具有手性螺旋结构的复合薄膜PBMA-b-PEO/TA。利用小角X射线散射(SAXS)、透射电子显微镜(TEM)和圆二色光谱(CD)对嵌段共聚物复合薄膜进行表征,研究了嵌段质量分数对手性诱导嵌段共聚物螺旋结构自组装的影响。结果表明:掺入TA与嵌段共聚物质量比为0.12、0.15的TA,当PEO质量分数为0.17~0.24时,有利于嵌段共聚物相分离形成柱状螺旋结构;当PEO质量分数增加至0.26时,嵌段共聚物自组装则形成层状结构,在分子间氢键作用下虽然发生手性转移,但无法得到螺旋结构。

       

      Abstract: In recent years, supramolecular helical assembly in bulk copolymers have attracted intensive attention due to their unique structures and advantages, especially in designing functional materials. Based on the previous study in our group, it has been found that the helical assembly of block copolymers(BCP)based on additive driven is affected greatly by the composition of the block copolymers. In this work, the effect of molecular weight of polymer segment on the helical self-assembly in bulk copolymer systems was investigated. Tartaric acid (TA) was chosen as a chiral additive and poly(butyl methacrylate)-b-poly(ethylene oxide) (PBMA-b-PEO) was selected as achiral block copolymer. Firstly, the line block copolymers, PBMA-b-PEO, with different PEO mass fractions, were synthesized by atom transfer radical polymerization (ATRP) method. Then, helical structure with controlled handedness was prepared by incorporating enantiopure TA molecule into block copolymer PBMA-b-PEO, in which intermolecular hydrogen bonding acted as a driving force to induce helical phases self-assembly. Small-angle X-ray scattering (SAXS), circular dichroic (CD) and transmission electron microscope (TEM) were used to characterize the helical structure of PBMA-b-PEO/TA systems. The experimental results proved that intermolecular hydrogen bonding between PEO block as a minority phase and TA can enhance the segregation strength of the systems. At the same time, the chiral information was transferred from TA molecular to achiral block copolymer to yield supramolecular helical structure. When PEO mass fraction was in the range of 0.17 to 0.24, the block copolymer could assemble into helical structures by adding TA(m(TA):m(Block copolymer)=0.12, 0.15). When the mass fraction of PEO was up to 0.26, a regular layer structure was formed by adding TA(m(TA):m(Block copolymer)=0.12, 0.15), in which chirality transfer occurred, but helical structure was not observed.

       

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