Gao Zhiqiang, Zhang Xu, Zheng Bowen, Gu Jingyuan, Tong Zaizai
School of Materials Science and Engineering and Institute of Smart Biomedical Materials, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Zhejiang Sci-Tech University Shengzhou Innovation Research Institute, Shengzhou 312400, China.
J Am Chem Soc. 2025 Feb 12;147(6):5172-5181. doi: 10.1021/jacs.4c15602. Epub 2025 Feb 2.
Two-dimensional (2D) platelet structures with uniform dimensions and spatially defined diverse cores are highly sought but are still challenging to access. Living crystallization-driven self-assembly (CDSA)-seeded growth enables the creation of uniform 2D core-shell nanomaterials with diverse core compositions via sequential epitaxial crystallization of block copolymers. Nevertheless, general limitation of the growth process to strict requirements of heteroepitaxial crystallization is a major obstacle to the formation of segmented nanoparticles with extended diverse core chemistries. Herein, we introduce a strategy of using double-crystalline triblock copolymers, such as poly(ε-caprolactone)--poly(-dioxanone)--poly(-dimethyl acrylamide) (PCL--PPDO--PDMA), as bridges to create segmented platelets with compositionally distinct cores. The epitaxial crystallization of the PCL block excludes the PPDO block, forming out-of-plane PPDO crystals that seed subsequent epitaxial crystallization of the added PPDO unimer, producing flat-on quasi-square PPDO crystals. Meanwhile, the less-defined orientation of PPDO crystals has confirmed the presence of flat-on epitaxy between PCL and PPDO. For comparison, PCL--PHL (PHL = poly(ζ-heptalactone)) forms in-plane crystals with a strictly defined orientation via edge-on epitaxy due to the cocrystallization of PCL and PHL. Therefore, this approach provides a novel route to construct precisely controlled segmented 2D platelet structures with chemically distinct cores and tunable functionalities, an extension to expand the precise design of complex nanoparticles.
具有均匀尺寸和空间定义的不同核心的二维（2D）血小板结构备受追捧，但获取起来仍具有挑战性。活性结晶驱动自组装（CDSA）引发的生长能够通过嵌段共聚物的顺序外延结晶来制备具有不同核心组成的均匀二维核壳纳米材料。然而，生长过程对异质外延结晶严格要求的普遍限制是形成具有扩展的不同核心化学组成的分段纳米颗粒的主要障碍。在此，我们引入一种策略，即使用双结晶三嵌段共聚物，如聚（ε-己内酯）-聚（-二氧杂环己酮）-聚（-二甲基丙烯酰胺）（PCL-PPDO-PDMA），作为桥梁来创建具有组成不同核心的分段血小板。PCL嵌段的外延结晶排除了PPDO嵌段，形成面外PPDO晶体，这些晶体引发添加的PPDO单体的后续外延结晶，产生平躺的准方形PPDO晶体。同时，PPDO晶体不太明确的取向证实了PCL和PPDO之间存在平躺外延。相比之下，PCL-PHL（PHL = 聚（ζ-庚内酯））由于PCL和PHL的共结晶，通过边缘外延形成具有严格定义取向的面内晶体。因此，这种方法提供了一种新颖的途径来构建具有化学上不同核心和可调功能的精确控制的分段二维血小板结构，这是扩展复杂纳米颗粒精确设计的一种延伸。
