Scheer Pieter van der, Laar Ties van de, Sprakel Joris
Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, The Netherlands.
Sci Rep. 2019 Aug 2;9(1):11217. doi: 10.1038/s41598-019-47537-2.
Semiconducting polymers doped with a minority fraction of energy transfer acceptors feature a sensitive coupling between chain conformation and fluorescence emission, that can be harnessed for advanced solution-based molecular sensing and diagnostics. While it is known that chain length strongly affects chain conformation, and its response to external cues, the effects of chain length on the emission patterns in chromophore-doped conjugated polymers remains incompletely understood. In this paper, we explore chain-length dependent emission in two different acceptor-doped polyfluorenes. We show how the binomial distribution of acceptor incorporation, during the probabilistic polycondensation reaction, creates a strong chain-length dependency in the optical properties of this class of luminescent polymers. In addition, we also find that the intrachain exciton migration rate is chain-length dependent, giving rise to additional complexity. Both effects combined, make for the need to develop sensoric conjugated polymers of improved monodispersity and chemical homogeneity, to improve the accuracy of conjugated polymer based diagnostic approaches.
掺杂少量能量转移受体的半导体聚合物具有链构象与荧光发射之间的敏感耦合，可用于先进的基于溶液的分子传感和诊断。虽然已知链长会强烈影响链构象及其对外部线索的响应，但链长对发色团掺杂共轭聚合物发射模式的影响仍未完全理解。在本文中，我们探索了两种不同受体掺杂的聚芴中链长依赖性发射。我们展示了在概率缩聚反应过程中受体掺入的二项分布如何在这类发光聚合物的光学性质中产生强烈的链长依赖性。此外，我们还发现链内激子迁移率与链长有关，这带来了额外的复杂性。这两种效应结合在一起，使得有必要开发具有更高单分散性和化学均匀性的传感共轭聚合物，以提高基于共轭聚合物的诊断方法的准确性。
