Synthesis and Characterization of Conjugated Diblock Copolymers (Co-Oligomers)

本研究的目的是建立一个充满活力的计划，以合成各种明确的，共轭二嵌段共聚物，并研究其物理性能。 共辄二嵌段共聚物具有棒-棒结构，并且将表现出不同于棒-线圈类型的共聚物。 这些共轭嵌段共聚物是一种新型的电活性聚合物结构。 这项工作的主要目标是了解的电子和结构的性质，棒-棒类型的二嵌段共聚物将表现出。 为了探索这些性质，共轭嵌段的各种组合及其合成方法在这个建议中概述。 这些组合从具有不同的两亲性质到具有不同的电子性质而变化。 一系列的功能化共轭低聚物，从低聚噻吩和oligophenylenevinylenes，oligophenylenes，将被合成。 这些低聚物的电子和物理性质将被调查作为数据库，为他们的比较与二嵌段共聚物（或共低聚物）。 几种得到的低聚物将被偶联形成具有各种共轭长度和电子性质的二嵌段共聚物。 由于这些嵌段共聚物可以进行相分离并形成自组装，因此将进行自组装的微观研究以发现其分子堆积和相行为的基本原理。 具有各种氧化还原性质的共聚物将被耦合，以探索电光性质，如光吸收和发光，光电导和电导率。 具有富电子嵌段和缺电子嵌段的共聚物将用连接到第一嵌段的亲水侧基和连接到第二嵌段的疏水部分官能化。 这些嵌段共聚物由于其分子内建的P-N结而具有很好的分子电子效应，将被用来制备L-B薄膜。 这些嵌段共聚物可以通过相分离组装成纳米级的连续微区，并在光电效应中发挥重要作用，其应用领域包括光电器件、电致发光器件、分子电子器件和光开关等。 实验探索导致这些应用程序的属性也提出了建议。

This research is aimed at establishing a vigorous project to synthesize various well-defined, conjugated diblock copolymers and to investigate their physical properties. A conjugated diblock copolymer possesses a rod-rod structure and will behave differently than rod-coil types of copolymers. These conjugated diblock copolymers are new architectures of electroactive polymers. The main goal of this work is to understand the kind of electronic and structural properties that the rod-rod types of diblock copolymers will exhibit. To probe these properties, various combinations of conjugated blocks and their synthetic approaches are outlined in this proposal. These combinations vary from having different amphiphilic properties to having different electronic properties. A series of functionalized conjugated oligomers, ranging from oligothiophenes and oligophenylenenvinylenes to oligophenlylenes, will be synthesized. The electronic and physical properties of these oligomers will be investigated as the database for their comparison with diblock copolymers (or co-oligomers). Several of the oligomers obtained will be coupled to form diblock copolymers with various conjugation lengths and electronic properties. Since these block copolymers can undergo phase separation and form self-assembly, microscopic studies of the self-assemblies will be carried out to find the principles underlying their molecular packing and phase behaviors. Copolymers with various redox properties will be coupled to explore electro-optic properties such as optical absorption and luminescence, and photoconductivity and electrical conductivity. Copolymers with an electron-rich block and an electron-deficient one will be functionalized with a hydrophilic side group attached to the first and hydrophobic moiety attached to the latter. These block copolymers will be sued to prepare L-B films, which are very interesting for their molecular-electronic effects due to their built-in molecular "P-N" junction. These block copolymers are expected to undergo phase separations to assemble into nanometer-continuous domains, which will be explored for photovoltaic effect.The investigation of possible applications of the diblock copolymers includes their use in electro-optic devises, such as photovoltaic and electroluminescent devices, molecular-electronic components, and optical switching. Experiments to explore the properties leading to those applications are also proposed.