中国科学技术大学洪勋团队报道了从二维纳米片到螺旋、扭曲和分枝纳米结构的可编程自组装。相关研究成果发表在2024年12月17日出版的《德国应用化学》。

纳米材料自组装成多层结构对制备功能材料具有重要意义。然而，组装结构的可编程设计仍然是一个巨大的挑战。

该文中，研究人员报告了一种可编程的自组装策略来定制组装结构。自组装策略旨在将二维（2D）钙离子组装的F127纳米片（Ca-F127 NSs），有序地转化为螺旋纳米片结构（S-Ca-F127 NSs）、支化纳米片结构。广角X射线散射（WAXS）和X射线吸收光谱（XAS）表明，这些不同的结构保持了相同的正交相和Ca-O八面体配位结构。

双倾斜液氮冷却架中的选区电子衍射（SAED）确定了扭曲结构中的Eshelby扭曲，表明螺旋结构是由螺位错生长形成的。冷冻电子显微镜（Cryo-EM）证明了B-Ca-F127 NSs中的定向外延生长。此外，螺旋结构和分支结构的形成机制可以重新组合，形成复杂的多层结构。沿螺位错的外延生长可导致B-S-Ca-F127 NSs的形成，而螺位错中的扭曲外延生长可引起T-Ca F127 NBs的形成。

附：英文原文

Title: Programmable Self-assembly from Two-dimensional Nanosheets to Spiral, Twisted and Branched Nanostructures

Author: Haohui Hu, Wei Jiang, Xiao Han, Geng Wu, Haoran Wang, Yi Shi, Dayin He, Xianhui Ma, Xun Hong

Issue&Volume: 2024-12-17

Abstract: Self-assembly of nanomaterials into hierarchical structure is of great interest to fabricate functional materials. However, programmable design of the assembled structures remains a great challenge. Herein, we reported a programmable self-assembly strategy to customize the assembled structure. The self-assembly strategy is designed to orderly transform the two-dimensional (2D) Ca ions assembled F127 nanosheets (Ca-F127 NSs) into spiral nanosheet structures (S-Ca-F127 NSs), branched nanosheet structures (B-Ca-F127 NSs), branched-spiral nanosheet structures (B-S-Ca-F127 NSs), and twisted-branched structures (T-Ca-F127 NBs). Wide-angle X-ray scattering (WAXS) and X-ray absorption spectroscopy (XAS) indicate that these different structures maintain the same orthorhombic phase and Ca-O octahedral coordination structure. Selected area electron diffraction (SAED) in the double-tilt liquid nitrogen cooling holder identifies the Eshelby twist in the twisted structures, demonstrating the spiral structure are formed by screw dislocation growth. Cryo-electron microscopy (cryo-EM) proves the oriented epitaxial growth in the B-Ca-F127 NSs. Furthermore, the formation mechanisms of spiral structure and branched structure can be recombined to form complex hierarchical structures. The epitaxial growth along screw dislocation can lead to the formation of B-S-Ca-F127 NSs, while the twisted epitaxial growth in the screw dislocation can lead to the formation of T-Ca F127 NBs.

DOI: 10.1002/anie.202416624

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202416624