Growing nanoscale polymer brushes on materials' surfaces overcomes a key challenge in surface chemistry, researchers report, creating a new way to fabricate a diverse array of materials that could hold advanced uses in catalysis or chemical separation applications, for example. Their approach represents a crucial step forward in the search for simple and general techniques to create functional surfaces with tailor-made chemical properties, writes Alejandro Presa Soto in a related Perspective; "Pandora's box is now open, and the limits of this approach are only restricted by the imagination and skills of the scientific community." As technology advances, the ability to create advanced materials with specific surface properties and functionalities is becoming critically significant in a wide variety of areas including chemical engineering and biomedicine.
One recently developed approach for creating functionalized surfaces makes use of polymer chains, grafted to surfaces in brush-like patches. However limited, the method allows for tailoring of the surface chemistry at the molecular level. Similar approaches using nano- or micron-scale structures hold great promise for greatly expanded functionality and applications; however, the precise fabrication of these surfaces remains a prohibitive challenge. Jiandon Cai and colleagues address this by growing nanoscale micellar brushes directly on a material's surface. Cai et al. attached small crystalline micelle-seeds on a variety of surfaces, including silicon wafers, graphene oxide nanosheets and gold nanoparticles.
Unimers are used to initiate the crystallization-driven growth of well-defined cylindrical nanostructures over the seed-coated surface. The approach allows for the precise control over the density, length and chemistry of the micellar brushes, which can further be outfitted with other functional molecules and nanoparticles to enable a variety of catalysis and antibacterial and chemical separation applications.