The use of crystallization as a tool to control the self-assembly of polymeric and molecular amphiphiles in solution is attracting growing attention for the creation of non-spherical nanoparticles and more...

The creation of nanostructures with precise chemistries on material surfaces is of importance in a wide variety of areas such as lithography, superhydrophobicity, and cell adhesion. We describe a platform for surface functionalization that involves the fabrication of cylindrical micellar brushes on a silicon wafer through seeded growth of crystallizable block copolymers at the termini of immobilized, surface-confined crystallite seeds. The density, length, and coronal chemistry of the micellar brushes can be precisely tuned, and post-growth decoration with nanoparticles enables applications in catalysis and antibacterial surface modification. The micellar brushes can also be grown on ultrathin two-dimensional materials such as graphene oxide nanosheets and further assembled into a membrane for the separation of oil-in-water emulsions and gold nanoparticles.

Toroidal nanostructures are of growing importance due to their unique geometry and potential utility in materials fabrication. Although a variety of amphiphilic block copolymers have been shown to selfassemble into toroidal micelles, the conventional methods used are often very slow with little control over the size of the resulting nanostructures. Here, we report a rapid and efficient synthetic route to prepare toroidal micelles of near uniform diameter through the cooperative co-assembly of amorphous blends of polyferrocenylsilane block copolymer and homopolymer, where the degree of polymerization of the core-forming metalloblock in the former is greater than for the latter. The selfassembly process is accomplished within a few minutes and the ring size of the toroids can be varied between 30 and 90 nm by adjusting the mass ratio of the block copolymer and homopolymer. The kinetic stability of the resulting toroidal micelles can be enhanced by frustrating core crystallization through solvent modulation and the toroids can also be readily used as templates to fabricate circular arrays of metal nanoparticles.

Controlled self-assembly of colloidal particles into predetermined organization facilitates the bottom-up manufacture of artificial materials with designated hierarchies and synergistically integrated functionalities. However, it remains a major challenge to assemble individual nanoparticles with minimal building instructions in a programmable fashion due to the lack of directional interactions. Here, we develop a general paradigm for controlled co-assembly of soft block copolymer micelles and simple unvarnished hard nanoparticles through variable noncovalent interactions, including hydrogen bonding and coordination interactions. Upon association, the hairy micelle corona binds with the hard nanoparticles with a specific valence depending exactly on their relative size and feeding ratio. This permits the integration of block copolymer micelles with a diverse array of hard nanoparticles with tunable chemistry into multidimensional colloidal molecules and polymers. Secondary co-assembly of the resulting colloidal molecules further leads to the formation of more complex hierarchical colloidal superstructures. Notably, such colloidal assembly is processible on surface either through initiating the alternating co-assembly from a micelle immobilized on a substrate or directly grafting a colloidal oligomer onto the micellar anchor.