Branched Aggregates with Tunable Morphology via Hierarchical Self-Assembly of Azobenzene-Derived Molecular Double Brushes

Hierarchical self-assembly is one of the most effective approaches to fabricate nature-inspired materials with subtle nanostructures. We report a distinct hierarchical self-assembly process of molecular double brushes (MDBs) with each graft site carrying a poly(azobenzene-acrylate) (PAzo) chain and a poly(ethylene oxide) (PEO) chain. Asymmetric tapered worm (ATW) nanostructures with chain-end reactivity assembling from the azobenzene-derived MDBs serve as primary subunits to prepare branched supermicelles by increasing water content (C-w) in THF/water. Various natural Antedon-shaped multiarm worm-like aggregates (MWAs) can be created via the particle-particle connection of ATWs. Intriguingly, the azobenzene moieties undergo trans-cis isomerization upon UV irradiation and further promote a morphology evolution of MWAs. Multiscale supermicelles comprised of starfish shapes with differing central body and arm morphologies (e.g., compare to the biological specimens Luidia ciliaris and Crossaster papposus) were prepared by manipulating irradiation time.

Automated summary

Hierarchical self-assembly of molecular double brushes (MDBs) can lead to nature-inspired materials with subtle nanostructures, utilizing the chain-end reactivity of asymmetric tapered worm (ATW) nanostructures and azobenzene moieties that undergo trans-cis isomerization upon UV irradiation. The resulting multiscale supermicelles exhibit starfish shapes resembling biological specimens, with differing central body and arm morphologies, achieved by manipulating irradiation time.