Shi Yi, Zhu Wen, Yao Dongdong, Long Meiling, Peng Bo, Zhang Ke, Chen Yongming
Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100190, China.
Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Department of Polymer and Material Sciences, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
ACS Macro Lett. 2014 Jan 21;3(1):70-73. doi: 10.1021/mz400619g. Epub 2013 Dec 30.
Self-assembling amorphous macromolecules into nanoparticles with a highly ordered internal structure and a defined shape is always a big challenge. Herein we present formation of soft disk-like micelles by hexagonally packing ABA amphiphilic triblock copolymers, whose B block is the molecular bottlebrush with densely grafted poly(-butyl acrylate)--polystyrene (PBA--PS) branches and A block is poly(-(2-methacryloyloxyethyl)pyrrolidone) (PNMEP). In a selective solvent of A segment, it was found that the ABA molecular bottlebrushes with stiffened middle blocks self-assembled two-dimensionally into disks with a uniform thickness of about 33 nm and a diameter of hundreds of nanometers. A hexagonal pattern of molecular bottlebrushes aligned perpendicularly to the disk plane with a periodic spacing of 9 nm was visualized by TEM through selective staining the PS shells of brushes. The aggregation number of ABA molecular bottlebrushes in each disk was counted directly from the stained TEM image.
将自组装无定形大分子组装成具有高度有序内部结构和特定形状的纳米颗粒一直是一项巨大的挑战。在此，我们展示了通过六方堆积ABA两亲性三嵌段共聚物形成的软盘状胶束，其B嵌段是带有密集接枝的聚（丙烯酸丁酯）-聚苯乙烯（PBA-PS）支链的分子刷，A嵌段是聚（2-甲基丙烯酰氧基乙基）吡咯烷酮（PNMEP）。在A链段的选择性溶剂中，发现中间嵌段变硬的ABA分子刷在二维上自组装成厚度约为33 nm、直径为数百纳米的圆盘。通过对分子刷的PS壳进行选择性染色，用透射电子显微镜（TEM）观察到分子刷垂直于圆盘平面排列的六边形图案，其周期间距为9 nm。每个圆盘中ABA分子刷的聚集数直接从染色的TEM图像中计数。
