Department of Chemistry , Seoul National University , Seoul , 08826 , Korea.
Institute for Organic Chemistry , Johannes Gutenberg University , Duesbergweg 10-14 , 55128 , Mainz , Germany.
J Am Chem Soc. 2018 May 16;140(19):6088-6094. doi: 10.1021/jacs.8b01954. Epub 2018 May 1.
Well-defined nanostructures composed of conjugated polymers have attracted significant attention due to their intriguing electronic and optical properties. However, precise control of the size and uniformity of these semiconducting nanostructures is still rare and challenging, despite recent advances in strategies to obtain self-assembled nanostructures with narrow dispersions. Herein, we demonstrate the preparation of fluorescent conjugated block copolymers by one-shot polymerization and rapid formation of nanofibers in a few minutes via light-induced crystallization-driven self-assembly, driven by facile cis-to- trans photoisomerization of its poly( p-phenylenevinylene) blocks. Furthermore, living self-assembly was possible, allowing not only nanofibers with excellent length control and narrow size distribution but also ABA triblock comicelles and gradient comicelles, to be produced by seeded growth. Lastly, the seeded growth could be activated and deactivated repeatedly by switching the light on and off, analogous to light-induced living radical polymerization.
由于具有有趣的电子和光学性质，由共轭聚合物组成的形貌明确的纳米结构引起了人们的极大关注。然而，尽管在获得具有较窄分散度的自组装纳米结构的策略方面取得了最新进展，但对这些半导体纳米结构的尺寸和均一性的精确控制仍然很少见且具有挑战性。在此，我们通过光诱导结晶驱动的自组装，在几分钟内快速形成纳米纤维，证明了通过一次聚合制备荧光共轭嵌段共聚物，这是由其聚（对苯撑乙烯基）嵌段的易于顺-反光异构化驱动的。此外，通过种子生长，还可以实现活的自组装，不仅可以制备具有出色的长度控制和较窄尺寸分布的纳米纤维，还可以制备 ABA 三嵌段胶束和梯度胶束。最后，通过打开和关闭光源，可以反复激活和失活种子生长，类似于光诱导的活性自由基聚合。
