Robust hybrid nanostructures comprising gold and thiol-functionalized polymer nanoparticles: Facile preparation, diverse morphologies and unique properties

Nanohybrids are generated via covalent integration of Au nanoparticles (NPs) with thiol-functionalized crosslinked polymer NPs. The polymer NPs have been readily prepared by the controlled intramolecular crosslinking of long-chain highly branched polymers through the thiol-ene reaction in dilute solution, and the thiol groups on polymer NPs can be introduced and tailored by alternating the cross linkers with various thiol functionalities, which facilitates the further fabricatation of nanohybrids with different loadings of Au NPs. The structures and optical properties of these nanostructures are characterized by elemental analysis, IR, NMR, XPS, XRD, and UV-vis measurements. The morphologies of nanostructures are investigated via dynamic light scattering, atom force microscopy, transmission electron microscopy, and cryogenic transmission electron microscopy. The results reveal that the crosslinked polymer NPs have an average diameter of 45 nm, and Au NPs in the nanohybrids are isolated and distributed throughout the surface of the polymer NPs. When varying the concentrations, the hybrid nanostructures display diverse morphologies going through nanosphere, chainlike assembly and nanorod, accompanied with unique optical properties. Additionally, this type of hybrid nanostructure has high stability and recoverability in catalysis, and shows excellent efficiency for the reduction of nitro compounds.