华中科技大学朱锦涛团队报道了超分子瓶刷嵌段共聚物的可编程重构——从溶液自组装到共结晶辅助自组装。相关研究成果于2024年8月6日发表在《德国应用化学》。

实现超分子瓶刷嵌段共聚物向拓扑工程的结构重构是特别有趣但具有挑战性的。

该文中，研究人员讨论了超分子结构的创建，以发现组装拓扑结构如何影响结构化聚集体，结合氢键（氢键）瓶刷嵌段共聚物和静电相互作用诱导的聚合物/无机共晶。研究人员首先设计了氢键线性刷嵌段共聚物P(NBDAP-co-NBC)-b-P(NBPEO)，带有氢键DAP（二氨基吡啶）基序的线性嵌段P（NBDAP-co-NBC）（聚（降冰片烯封端的二氨基吡啶-co-降冰片烯端接的己烷），以及PEO（聚环氧乙烷）密集接枝的P（NBPEO）刷嵌段。由于DAP和胸腺嘧啶（Thy）之间的氢键结合，掺入Thy官能化聚苯乙烯（Thy PS）能够实现溶液自组装和氢键化瓶刷嵌段共聚物的形成，随着Thy PS量的增加，产生增强的纳米球。

值得注意的是，无机簇合硅钨酸（STA）与P(NBDAP-co-NBC)-b-P(NBPEO)的结合，赋予了PEO/STA共晶核的形成。因此，通过在固定STA含量的同时逐渐增加Thy-PS，实现了聚合物、无机和超分子化学界面上的共结晶辅助自组装，反映了从六边形片状、针状、弯曲棒状胶束到端到端闭环的多阶段形态转变。有趣的是，这种溶液自组装到共结晶辅助自组装策略不仅赋予了独特的纳米结构转变，还诱导了PS结构域的由内到外的转换。

以上发现显然为智能材料中有前景的几何物体的可编程制造，提供了独特的方法。

附：英文原文

Title: Programmable Reconfiguration of Supramolecular Bottlebrush Block Copolymers: From Solution Self-Assembly to Co-Crystallization-Assistant Self-Assembly

Author: Kaixing Zhang, Senbin Chen, Jintao Zhu

Issue&Volume: 2024-08-06

Abstract: Achieving structural reconfiguration of supramolecular bottlebrush block copolymers toward topological engineering is of particular interest but challenging. Here, we address the creation of supramolecular architectures to discover how assembled topology influences the structured aggregates, combining hydrogen-bonded (H-bonded) bottlebrush block copolymers and electrostatic interaction induced polymer/inorganic eutectics. We first design H-bonding linear-brush block copolymer P(NBDAP-co-NBC)-b-P(NBPEO), bearing linear block P(NBDAP-co-NBC) (poly(norbornene-terminated diaminopyridine-co-norbornene-terminated hexane)) with pendant H-bonding DAP (diaminopyridine) motifs, and PEO (poly(ethylene oxide)) densely grafted P(NBPEO) brush block. Thanks to H-bonding association between DAP and thymine (Thy), incorporation of Thy-functionalized polystyrene (Thy-PS) enables solution self-assembly and formation of H-bonded bottlebrush block copolymers, generating augmented nanospheres with increasing Thy-PS amount. Noteworthy that integration of inorganic cluster silicotungstic acid (STA) to P(NBC-co-NBDAP)-b-P(NBPEO), endows the formation of PEO/STA eutectic core. Therefore, co-crystallization-assistant self-assembly at the interfaces of polymeric, inorganic and supramolecular chemistry is realized, reflecting multi-stage morphology transformation from hexagonal platelets, needle-like, curved rod-like micelles, finally to end-to-end closed rings, by gradually increasing Thy-PS while fixing STA content. Interestingly, such solution self-assembly to co-crystallization-assistant self-assembly strategy not only endows unique nanostructure transition, also induce in-to-out switch of PS domains. These findings clearly provide unique methodology towards programmable fabrication of geometrical objects promising in smart materials.

DOI: 10.1002/anie.202408730

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202408730