Self-Assembly of Nanoparticles Induced by Polymer Brushes

The ability to assemble nanoparticles (NPs) into ordered superstructures is important to the development of devices for a range of applications including energy harvesting and storage, magnetic storage, plasmonics, electronics, drug-delivery, catalysis, imaging, and biosensing. While assemblies of NPs into various structures can be obtained through top-down approaches such as lithography, these techniques require precise placement of the NPs, which relies on careful calibration and clean environment. These techniques also suffer from a range of limitations including the synthesis of structures with characteristic length scales smaller than ~10 nm. Using molecular dynamics simulations of a coarse-grained implicit-solvent model, we show that polymer brushes in good solvent conditions can mediate the self-assembly of spherical NPs into ordered hexagonally-close-packed superstructures over a wide range of NP-polymer interactions. We show that these structures are the result of the chains' conformational anisotropy and gradients in the polymer density profile.