Conjugated polymers are attractive soft materials that have gained a lot of attentions due to their interesting optoelectronic properties. In this presentation, we will focus on the new strategies for the formation of semiconducting 2D nanostructures via self-assembly approach. Conventional polymer adapts random coil conformation while many conjugated polymers are semi-rigid. Furthermore, these conjugated polymers form π-π stacking to one another so they are easily aggregated showing much lower solubility. As a result, due to their high rigidity and crystallinity, controlling their morphologies are challenging. Here, taking advantageous of these facts, we designed several diynes monomers containing fluorene side-chains and performed cyclopolymerization using 3rd generation Grubbs catalyst. These new homopolymers of polyacetlyene derivatives underwent self-assembly to form various 2D nanostructures which are simply beyond the conventional structures of typical polymers. The resulting nanostructures are characterized by UV-vis, IR, DLS, AFM, TEM, and optical microscopy to obtain the detailed structural information. We will start with how we could control the shape of 2D nanosheets and then discuss how to control their sizes and aspect ratios by combining the concept of crystallization-driven self-assembly. Since conjugated polymers are attractive soft materials for their interesting optoelectronic properties, we hope these new 2D nanosheets would find useful applications in electronic devices.

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