仿生寡聚多肽侧链修饰的长链聚噻吩的微观纳米结构调控研究

How to realize the flexible and effective control of molecular arrangement in order to regulate material properties, has been always one of important issues for material scientists. Polythiophene, as a special kind of organic conjugated material, becomes the research hot topic in this research field. The performance of polythiophene material might be adjusted by control of molecular arrangement utilizing the introduction of H-bonding and the blance between H-bond assembly from oligopeptide and π-π interaction from conjugated molecule. However, the related research mainly focuses on these oligomer systems that include thiophene units less than five and can form organic gel, and the research on autonomic control of the nanostructure of long chain polythiophene (directly connected thiophene units > 10) is rarely reported. Based on the previous results in our group, we proposed to synthesize series of long chain polythiophene polymers with oligopeptide side chains. These long chain polythiophene polymers have been designed with different molecular weight, different graft density of peptide sidechains, and different regio-regularity of polythiophene. The balance between H-bond assembly from oligopeptide and π-π interaction from conjugated molecular will be regulated with the change of all these structure parameters in long chain polythiophene. By this method, It is anticipated that the flexible and effective control of molecular arrangement of these polythiophene polymers will be realized, which might provide experimental and theoretical bases for potential application of this kind of material in the future.

如何实现分子微观排列的灵活有效调控，从而掌握材料相关性能的调控，一直是材料学家们长久不衰的一个重要研究方向。聚噻吩作为一类特殊有机共轭材料成为这方面研究的热点。利用寡聚多肽氢键的自组装和噻吩单元之间的π-π相互作用的协调来实现材料分子微观排列的有效调控，是赋予这类材料优良应用性能的重要因素。但是，相关的研究主要集中在噻吩单元少于五个、能形成有机凝胶态结构的齐聚物上，而利用寡聚多肽自主调控长链聚噻吩（直接相连的噻吩单元﹥10）微观形貌的研究却鲜见报道。在前期研究基础上，本项目致力于制备不同分子量、不同区域规整性、不同接枝密度的、寡聚多肽侧链修饰的长链聚噻吩，进一步探求如何利用聚合物结构参数的变化来协调氢键和π-π之间相互作用的协同-竞争关系，实现有规律地调控分子的微观排列。本项目的开展为实现灵活调控长链聚噻吩的微观纳米结构和扩展这类材料潜在的应用提供实验和理论依据。

聚噻吩是一类特殊的有机共轭材料成为相关领域研究的热点。本项目制备不同分子量、不同区域规整性、不同接枝密度的、寡聚多肽侧链修饰的长链聚噻吩，进一步探求了利用聚合物结构参数的变化来协调氢键和π-π之间相互作用的协同-竞争关系，实现有规律地调控聚噻吩的微观排列。研究过程中，利用扫描电镜、紫外可见光吸收光谱、红外光谱分别证实了不同冷却方式、不同溶剂体系会明显影响寡聚多肽修饰的聚噻吩的微观组装结构。实验结果证明，采取慢速冷却，制备的嵌段/无规结构的寡聚多肽修饰的聚噻吩组装形成球形或纤维状结构；慢速冷却易于组装。另外，不同的溶剂体系也能影响组装行为，在DMF体系组装形成β结构。本项目的开展为实现灵活调控长链聚噻吩的微观纳米结构和扩展这类材料潜在的应用提供实验和理论依据。