Self-healing of conjugated polymers - Synthesis, Mechanistic Studies and Photophysical Properties

自修复聚合物具有独特的性能，即在损坏事件后可以恢复其原始功能。近年来，已经研究了许多方法，其允许机械损伤的愈合;即，（部分）恢复了原始的机械性能。然而，对其他属性（例如，光学性质、电子传导性）仍处于起步阶段。在这种情况下，该合作项目的目的是可逆连接的共轭低聚物/聚合物的合成和光谱表征，这在一定程度上可以实现用于光电应用的自修复聚合物。在这个项目中遵循的有针对性的整体方法的目的不仅在可逆连接的共轭低聚物/聚合物的合成和光谱表征，但此外，在获得基于这种材料的聚合物膜的自愈过程的机械理解。基于不同的共轭低聚物，将合成新型可逆连接的共轭聚合物。将改变可逆交联剂以获得与降解产物正交的官能团，并调节所需的愈合温度。随后，这些材料的光致激子动力学将在溶液中，并在时间分辨光谱研究。聚合物膜将在受控条件下通过UV照射和/或通过在环境空气存在下的氧化而老化，从而模拟有机电子器件中聚合物的最普遍的降解途径之一。老化材料的光学性质的自修复将在温度处理（整体或区域退火）后进行研究。因此，光致激子动力学将被引入作为老化和随后的自修复和瞬态吸收显微镜的自修复聚合物研究领域的度量。通过研究新材料中的激子动力学，即在原始材料，老化和愈合的材料中，该项目不仅考虑自愈合的结构方面，而且专注于描述老化和自愈合对这些聚合物材料功能的影响。因此，所提出的工作将有助于将优先计划SPP 1568自修复材料的设计和通用原则的重点扩展到功能材料的修复。

Self-healing polymers feature the unique property that their original functionality can be restored after a damage event. In recent years, many approaches have been investigated, which allow the healing of mechanical damage; i.e., the original mechanical properties are (partially) restored. However, the research on self-healing of other properties (e.g., optical properties, electronic conductivity) is still in its infancy. In this context this cooperation projects aims at the synthesis and spectroscopic characterization of reversibly linked conjugated oligomers/polymers, which in perspective could allow for the realization of self-healing polymers for optoelectronic applications. The targeted holistic approach followed in this project aims not only at the synthesis and spectroscopic characterization of reversibly linked conjugated oligomers/polymers but furthermore at deriving a mechanistic understanding of the self-healing processes in polymer films based on such materials. Novel reversibly linked conjugated polymers based on different conjugated oligomers will be synthesized. The reversible crosslinker will be varied in order to obtain functional groups, which are orthogonal to the degradation products, and to tune the required healing temperature. Subsequently, the photoinduced exciton dynamics of these materials will be investigated in solution and in by time-resolved spectroscopy. Polymer films will be aged under controlled conditions either by UV irradiation and/or by oxidation in the presence of ambient air, thus mimicking the one of the most prevalent degradation pathways of polymers in organic electronic devices. The self-healing of the optical properties of the aged materials will be investigated after temperature treatment (globally or by zone annealing). Thereby the photoinduced exciton dynamics will be introduced as a metric for aging and subsequent self-healing and transient absorption microscopy is introduced to the field of self-healing polymer research. By studying the exciton dynamics in the novel materials, i.e. in the virgin materials, the aged and the healed materials, this project does not (only) consider structural aspects of self-healing but focusses on describing the effect of aging and self-healing on the function of these polymeric materials. Thereby, the work proposed will contribute to extending the focus of the priority program SPP 1568 Design and Generic principles of Self-healing Materials towards the healing of functional materials.