Toward the alignment of conjugated polymers into anisotropically-ordered structure

Abstract

Recently, oriented polymers and/or polymer nanostructures have attracted a large amount of attention for their potential applications as, for example, electric devices such as FETs, LEDs, photovoltaic cells, and so forth. Besides several methods for organizing conjugated polymers, we have recently reported a novel concept for the alignment of conjugated polymers through the action of supramolecular bundling molecules. We here introduce two different approaches for aligning conjugated polymers; one is to utilize a crosslinking molecule (‘aligner’), and the other is to use a twining polymer (‘twimer’) for organizing conjugated polymers. Aligner binds and crosslinks conjugated polymers in a positive allosteric manner to form organized supramolecular assemblies in solution. The cast film from the solution resulted in a crystalline sheet with periodicities corresponding to the distance between polymers, confirmed by several microscopic studies. On the other hand, twimer helically twins around the conjugated polymers to form one-dimensional (1D) complex in solution and the complex self-assembles into two-dimensionally (2D) aligned structure in drying process. The resulting film of conjugated polymer–twimer composites gave also highly ordered, crystalline structure. The principal results obtained both in solution and solid states and their future perspectives are discussed here.