Revealing into the formation mechanism of various nanostructures self-assembled from a bipyridine containing homopolymer

The control of the morphology and nanostructure of soft nanomaterials self-assembled from amphiphilic polymers has attracted significant attention. In this study, various nanostructures including bowl-shaped nanoparticles with controlled openings, round Yuanbao-shaped assemblies, nanowires and butterfly shaped twin nanosheets are formed by manipulating the self-assembly pathway of an amphiphilic homopolymer. The amphiphilic (poly( N -(2,2′-bipyridyl-4-acrylamide), PBPyAA) with bipyridine pendants is designed and synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization, which can self-assemble into bowl-shaped nanoparticles with controlled openings by solvent switch method at different initial concentrations. In addition, core–shell nanostructures are obtained taking advantage of the coordination between bipyridine and Fe 2+ . Upon annealing in ethanol, butterfly shaped twin nanosheets with thickness of about 10 nm are formed by controlling the cooling rate, while round Yuanbao-shaped assemblies are formed by naturally cooling. Revealing into the formation mechanism of the butterfly shaped twin nanosheets, a fusion induced assembly process of nanowires is observed. Overall, various nanostructures are obtained by manipulating the self-assembly pathways of a bipyridine containing amphiphilic homopolymer.