【作者】 王慧萍；

【导师】 马於光；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2010， 博士

【摘要】 共轭聚合物是一类集合了半导体的光学、电学性能与聚合物优异的机械加工性能、易操作性能的新型材料。目前,共轭聚合物已经被广泛的应用于光电器件及传感器等领域。共轭聚电解质是一类包含共轭主链和可以在极性溶剂中离子化的功能性官能团的聚合物。由于集合了电子离域聚合物的半导体性质和光捕获性质,以及聚电解质的电荷调节行为,共轭聚电解质表现出一些不同于中性共轭聚合物的独特的性质与功能,从而引起了人们的广泛关注。本论文立足于新型共轭聚电解质、聚合物的设计与合成。一方面致力于提高共轭聚电解质在水中的溶解度,通过结构修饰调控共轭聚电解质的性质。另一方面设计合成了一系列侧链含有功能性官能团的共轭聚合物和齐聚物,它们的侧链官能团可与氟离子发生反应生成共轭聚电解质,应用这一性质可以制备化学方法固定的p-n结聚合物半导体双层器件。主要工作包括以下几个方面:1.通过在侧链上引入高的电荷密度和采用合适的侧链长度,合成了一种在水中具有极高的溶解度和很高的荧光量子效率的共轭聚电解质。将此材料作为电子注入层,可以有效地改善有机发光二极管的器件性能。通过调节聚电解质的季胺化程度,可以调节其在水中的溶解度,从而有效地调控其在溶液以及薄膜中的光物理性质。合成了一系列水溶性的芴与联吡啶的共聚物,研究了它们在水溶液中的光学性质和离子传感性质。2.设计合成了一种新型的含有芴-苯共轭主链和二米基硼官能团侧链的共轭聚合物。该聚合物的二米基硼可以与氟离子反应从而形成共轭聚电解质。应用这种聚合物和抗衡离子为氟离子的共轭聚电解质,利用B-F共价键的形成,可以制备化学固定的p-n结有机半导体双层器件。这个器件的发光电化学池行为没有开启延迟,并且表现出了极好的电流整流。3.通过不同的合成方法与结构设计的尝试,合成了一种可溶性的同时含寡聚氧化乙烯侧链与二米基硼官能团的共轭聚合物。为了更好地理解含这两种官能团聚合物的结构与性质的关系,合成了它们的模型化合物-齐聚物,初步研究了其光学性质与热力学性质。更多还原

【Abstract】 Conjugated polymers are a novel class of materials that combine the optical and electronic properties of semiconductors with the attractive mechanical properties and processing advantages of polymers. These days, conjugated polymers have been widely used in optoelectronic devices and sensors. Conjugated polyelectrolytes (CPEs) are polymers that contain aπconjugated backbone and functional groups that ionize in high dielectric media. Because of combining the semiconducting and light harvesting properties characteristic of electronically delocalized polymers with the charge-mediated behavior of polyelectrolytes,conjugated polyelectrolytes exhibit some unique properties and functionalities as compared with neutral conjugated polymer, and thus become more and more attractive in recent years. Because the properties of conjugated polymers can be fined-tuned by manipulation of their chemical structures, considerable research efforts have been directed towards the preparation of well-defined conjugated polymers. This thesis mainly focused on the design and synthesis of novel conjugated polyelectrolytes/polymers. On one hand, we aimed on increasing the water solubility of conjugated polyelectrolytes and adjusting conjugated polyelectrolytes properties by modification of the structure. On the other hand, we designed and synthesized several conjugated polymers/oligomers with functionalized groups on the side chains which can combine a fluoride ion and form conjugated polyelectrolytes. By application of this property, these polymers can be used for fabrication of chemically fixed p-n junction polymer semiconducting bilayers.Conjugated polyelectrolytes (CPEs) presumably tends to come together and aggregate to minimize exposure of the backbone to polar solvent such as water due to the extremely hydrophobic nature of the conjugated backbone. Lots of reported conjugated polyelectrolytes behave with low solubility and low fluorescence in water, which badly limited their applications. So it is most important to design and synthesize water-soluble conjugated polymers with high solubility. By introducing high charge density to the side chains of the polymer and adopting appropriated side chain length, we synthesized a water soluble conjugated polymer with excellent water solubility up to 100 mg ml-1 as well as high PL quantum yield of 44% in water. The standard NPB/Alq3 device using this polyelectrolyte as the electron injection layer shows nearly 3 times enhancement in the EL efficiency. Through controlling of the reaction time we have synthesized a series of conjugated polyelectrolytes with different quaternization degrees. The relationships of the solubility and the PL quantum yield with the quaternization degree have also been demonstrated. AFM was used to investigate the aggregation behavior of the polyelectrolytes in films. By rational incorporation of functional group-bipyridyl to the conjugated backbone, we have prepared a series of fluorene based bipyridine containing water soluble conjugated polymers. The aqueous solution behavior and ion responsive properties of these polyelectrolytes were studied.In LECs, the ion motion that is required for the operation of these devices leads to long temporal responses and a dynamic electronic structure. So, the development of new materials and new methods to fix the ions is desirable. We designed and prepared a new conjugated polymer PFP-BMes which composed of poly (fluorene-co-phenylene) PFP conjugated backbone and dimesitylboron functionality attached to its side chains. The dimesitylboryl group in PFP-BMes can be modified by a fluoride source in solution, and thus form a polyelectrolyte. A permanently-fixed organic p-n heterojunctions can thus be achieved by using this polymer with dimesitylboron functionality (anion-trapping functional groups) and an uplayer of a cationic conjugated polyelectrolyte (CPE) with fluoride counteranions. The devices show no delay in the turn on of light-emitting electrochemical behavior and excellent current rectification.The ionic conducting polymer poly(ethylene oxide) (PEO) is usually used to facilitate the ion motion in a typical LECs. However, due to the polarity difference of the PEO and the EL polymers, phase separation between these two polymers occurs as they mixed together, which can significantly degrade the device performance. In order to solve this problem, we sought to incorporate short PEO chains into dimesitylboryl functionality containing conjugated polymers. However, the desired polymer encountered a solubility problem. Different synthetic strategies were tried and a variety of polymer structures were designed to make this kind of polymer soluble. Finally, by rational incorporation of a unit with branched structures, we got a conjugated polymer with very good solubility. To better understand the relationship between the property and structure of this kind of polymers, we synthesized an oligomer combining both of the functionalities, and studied its optical properties and thermal properties.更多还原