Xu Zhuang, Park Kyung Sun, Diao Ying
Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, United States.
Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL, United States.
Front Chem. 2020 Dec 22;8:583521. doi: 10.3389/fchem.2020.583521. eCollection 2020.
The hierarchical assembly of conjugated polymers has gained much attention due to its critical role in determining optical/electrical/mechanical properties. The hierarchical morphology encompasses molecular-scale intramolecular conformation (torsion angle, chain folds) and intermolecular ordering (π-π stacking), mesoscale domain size, orientation and connectivity, and macroscale alignment and (para)crystallinity. Such complex morphology in the solid state is fully determined by the polymer assembly pathway in the solution state, which, in turn, is sensitively modulated by molecular structure and processing conditions. However, molecular pictures of polymer assembly pathways remain elusive due to the lack of detailed structural characterizations in the solution state and the lack of understanding on how various factors impact the assembly pathways. In this mini-review, we present possible assembly pathways of conjugated polymers and their characteristics across length scales. Recent advances in understanding and controlling of assembly pathways are highlighted. We also discuss the current gap in our knowledge of assembly pathways, with future perspectives on research needed on this topic.
共轭聚合物的分级组装因其在决定光学/电学/机械性能方面的关键作用而备受关注。分级形态包括分子尺度的分子内构象（扭转角、链折叠）和分子间有序排列（π-π堆积）、介观尺度的域尺寸、取向和连通性，以及宏观尺度的排列和（准）结晶度。固态中的这种复杂形态完全由溶液状态下的聚合物组装途径决定，而溶液状态下的聚合物组装途径又受到分子结构和加工条件的灵敏调节。然而，由于缺乏溶液状态下的详细结构表征以及对各种因素如何影响组装途径缺乏了解，聚合物组装途径的分子图像仍然难以捉摸。在这篇综述中，我们介绍了共轭聚合物可能的组装途径及其在不同长度尺度上的特征。重点介绍了在理解和控制组装途径方面的最新进展。我们还讨论了目前在组装途径知识方面的差距，并对该主题未来所需的研究提出了展望。
