作者：Jie Cui, Entian Liu, Tongjing Song, Yuanyuan Han, Wei Jiang
关键字：矩形圆柱, ABC三嵌段三元共聚物, 自洽场理论, 共混物, 相图
论文来源：期刊
具体来源：Langmuir, 2021, 37(51), 14889-14897
发表时间：2021年

摘要：与传统圆形截面圆柱相比，矩形截面圆柱可赋予纳米材料各种新颖光学性能和功能。本文基于自洽场理论数值模拟研究了由组分双分散ABC三嵌段三元共聚物共混物自组装的矩形圆柱形成。特别设计的共混体系由两种总链长和中B嵌段链长相同、但侧A/C嵌段链长不同的线性ABC三嵌段三元共聚物组成。通过调节链长分数和不同嵌段间相互作用，模拟成功获得了具有四重对称图案的矩形圆柱。每个矩形相域由同种短链和长链侧嵌段共同自组装而成。模拟结果表明，短侧嵌段的选择性聚集决定矩形圆柱相的形成，即短侧嵌段倾向于聚集在矩形圆柱相域内的四个角。该结果揭示了与之前实验提出的不同形成机理。在不同中B嵌段链长分数下，构建了以不同嵌段间相互作用参数和短侧嵌段链长分数为变量的相图。相图表明，增加中B嵌段链长分数可显著扩大矩形圆柱的参数窗口。该模拟工作可为未来实验中调控和制备具有非传统相域的纳米材料提供分子设计理论基础。

Abstract：Compared with traditional cylinders that have circular cross-sections, cylinders with rectangular cross-sections can endow nanomaterials with various novel optical properties and functions. In this work, the formation of the rectangular cylinders self-assembled by compositionally bidisperse ABC triblock terpolymer blends has been investigated via numerical simulations based on self-consistent field theory. The specially designed blending systems are composed of two types of linear ABC triblock terpolymers that have the same total chain lengths and the middle B block chain lengths, but different chain lengths of the side A/C blocks. By tuning the chain length fractions and the interactions between different blocks, rectangular cylinders with a fourfold symmetry pattern were successfully obtained in our simulations. Each rectangular phase domain is self-assembled together by the short and long side blocks of the same species. The simulation results indicate that the selective aggregation of the short side blocks determines the formation of the rectangular cylindrical phase, i.e., the short side blocks prefer to aggregate at the four corners within a rectangular cylindrical phase domain. This simulation result reveals a formation mechanism that is different from the mechanism proposed in previous experiments. Moreover, under different middle B block chain length fractions, phase diagrams as a function of the interaction parameter between different blocks and the short side block chain length fraction have been constructed. The phase diagrams show that the parameter window of the rectangular cylinders is considerably expanded by increasing the chain length fraction of the middle B blocks. Our simulation works can provide a theoretical basis for molecular design to regulate and fabricate nanomaterials with nontraditional phase domains in future experiments.

论文链接：https://doi.org/10.1021/acs.langmuir.1c02713