Hierarchical Nanowires Synthesized by Supramolecular Stepwise Polymerization.

The self-organization of pre-assembled aggregates is an efficient stepwise strategy for fabricating nanostructures with a second level of hierarchy. Herein, we report that anisotropic spindle-like micelles, self-assembled from polypeptide graft copolymers with rigid backbones, can serve as ideal pre-assembled subunits for constructing one-dimensional materials with hierarchical structures. By adding organic solvents and dialyzing against water, reactive points can be generated at the ends of the spindle-like micelles, which subsequently drive the anisotropic micelles to grow as rods in a chain and eventually self-assemble into hierarchical nanowires in a stepwise manner. The second self-assembly step is a hierarchical process that resembles step polymerization. Hierarchical structures can be precisely synthesized by this new type of polymerization. These nanostructures can be tailored by the activity of the reactive points, which depends on the nature of the solvent and the molecular architecture.