Conductive supramolecular liquid-crystalline polymers by ionic self-assembly

该项目的总体目标是从现成的生物和合成材料中设计出易于加工但高度有序的具有各向异性和可切换光电性能的超分子材料。我们提出了一种基于离子自组装的方法，将低聚(苯胺)衍生物良好的电子性质与线性聚合物良好的成膜性能和液晶(LC)相结构的定向性结合起来。具有固定二级结构的离子多肽和合成聚合物将合成阳离子四(苯胺)衍生物和络合物。超分子聚合物络合物将被连续塑化，并使用大体积有机酸进行掺杂，以实现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)场中的取向性。为了促进对结构有序性和电子输运之间关系的理解，我们将研究四(苯胺)部分在特定纳米结构中的自组装对材料导电性的影响。在取向结构中，各向异性导电性以及相变时可切换的导电性是可以预期的。从应用的观点来看，这种对结构和功能的同时控制是可取的，并且可能导致在例如用于生物传感器的可打印各向异性导电材料中的潜在应用。

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.