Conductive supramolecular liquid-crystalline polymers by ionic self-assembly

该项目的总体目标是设计易于加工且高度有序的超分子材料，具有各向异性和可切换的光电特性，这些材料来自现成的生物和合成构建块。我们提出了一种基于离子自组装的方法，将低聚苯胺衍生物明确的电子性质与线性聚合物良好的成膜性能和液晶（LC）相结构的可定向性结合起来。将合成阳离子四（苯胺）衍生物，并由具有明确二级结构的离子多肽和合成聚合物制备配合物。超分子聚合物配合物将陆续使用大块有机酸进行塑化和掺杂，以获得液晶相行为和导电性能。将研究超分子聚合物的自组装和LC相行为，以及它们在外部（机械，磁场）中的定向性。为了促进对结构秩序和电子输运之间关系的理解，我们将研究四苯胺自组装成特定纳米结构对材料电导率的影响。在定向结构中，各向异性电导率以及相变时的可切换电导率是可以预期的。从应用的角度来看，这种对结构和功能的同时控制是可取的，并且可能导致潜在的应用，例如，用于生物传感器的可打印各向异性导电材料。

The overall aim of this project is to design easy-to-process yet highly ordered supramolecular materials with anisotropic and switchable optoelectronic properties from readily available biological and synthetic building blocks. We propose to combine the well-defined electronic properties of oligo(aniline) derivatives with the good film-forming properties of linear polymers and the orientability of liquid-crystalline (LC) phase structures in an approach based on ionic self-assembly. Cationic tetra(aniline) derivatives will be synthesised and complexes will be prepared from both ionic polypeptides with defined secondary structure and synthetic polymers. The supramolecular polymer complexes will successively be plasticised and doped using bulky organic acids in order to achieve liquid-crystalline phase behaviour and conducting properties. The self-assembly and LC phase behaviour of the supramolecular polymers, as well as their orientability in external (mechanical, magnetic) fields, will be investigated. To promote understanding of the relation between structural order and electronic transport, the impact of the self-assembly of the tetra(aniline) moieties into defined nanostructures on the materials conductivity will be studied. Anisotropic conductivity as well as switchable conductivity at phase transitions can be expected in oriented structures. Such a simultaneous control over structure and function is desirable from an application point of view, and may lead to potential applications in, for example, printable anisotropic conducting materials for biosensors.