Here we present a facile yet robust strategy to prepare polymer nano-bowls through 3D confined assembly and disassembly of block copolymers. Unlike the previously reported methods, this strategy allows for generation of nano-bowls with precisely controllable opening degree and thickness. Typically, polystyrene-b-poly(4-vinyl pyridine) (PS-b-P4VP) nano-bowls can be generated through confined assembly of PS-b-P4VP with homopolystyrene (hPS) to form Janus particles, followed by the crosslinking of P4VP domains and disassembly of PS domains. The opening degree of the nano-bowls can be precisely controlled by the weight fraction of hPS, and the thickness can be tailored by the varying molecular weight of PS-b-P4VP. By selectively loading gold nanoparticles in P4VP domains, it is anticipated that the resulting hybrid nano-bowls would be useful for surface enhanced Raman scattering and potential catalytic reaction applications.

The presence of surfaces influences the kinetics of amyloid-β (Aβ) peptide fibrillation. Although it has been generally recognized that the fibrillation process can be assisted or accelerated by surface chemistry, the impact of surface topography, i.e., roughness, on peptide fibrillation is relatively little understood. Here we study the role of surface roughness on surface-mediated fibrillation using polymer coatings of varying roughness as well as polymer microparticles. Using single-molecule tracking, atomic force microscopy, and the thioflavin T fluorescence technique, we show that a rough surface decelerates the two-dimensional (2D) diffusion of peptides and retards the surface-mediated fibrillation. A higher degree of roughness that presents an obstacle to peptide diffusion is found to inhibit the fibrillation process.

We develop a novel heterogeneous pattern with nanometer-sized spots surrounded with a bio-inert matrix by using a diblock copolymer thin film. The nanopattern with features down to 20 nm is highly resistant to protein adsorption and cell adhesion. By providing a domelike topography similar to biologically relevant size, such a heterogeneous nanopattern demonstrates an excellent anti-biofouling property to control protein–surface and cell–surface interactions at the molecular level.

Here we describe a facile yet effective route for the fabrication of crystal-like polymer microdiscs with a huge bump at the surrounding edge through hydrodynamic instabilities of emulsion droplets containing hydrophobic polymer and cosurfactant n-octadecanol (OD). This strategy allows for the generation of polymer particles with tunable size and shape by tuning the cosurfactant concentration, emulsion droplet size, and/or solvent evaporation rate. The generation of polystyrene (PS) microdiscs is balanced by the interfacial instabilities of emulsion droplets, crystallization of OD, and capillary flow. Our approach can be extended to different hydrophobic polymers and allows for the functionalization of the discs with tunable chemical/physical properties by incorporating functional species. By introducing magnetic nanoparticles, we have been able to manipulate the spatial orientation of the magnetic microdiscs via an external magnetic field. We anticipate this simple and versatile route to be useful for the design and fabrication of well-defined microparticles for potential applications in the fields of targeting, separation, sensing, drug delivery, and formation of advanced materials.

We develop a novel heterogeneous pattern with nanometer-sized spots surrounded with a bio-inert matrix by using a diblock copolymer thin film. The nanopattern with features down to 20 nm is highly resistant to protein adsorption and cell adhesion. By providing a domelike topography similar to biologically relevant size, such a heterogeneous nanopattern demonstrates an excellent anti-biofouling property to control protein–surface and cell–surface interactions at the molecular level.