One-Step Self-Assembly for Fabricating Asymmetric Particle Arrays and Templates for Bifunctional Systems

The assembly of microunits with different chemistries and morphologies into the arrays of a binary structure is of great interest in different fields such as bifunctional probes and bimodal triggered drug delivery. Although some binary structures have been designed, the fabrication of a non-close-packed structure with precise controllability of the subcomponent features remains a challenge. Herein, we report a one-step self-assembly approach for a highly ordered structure with anisotropic “ball-on-disk-shaped” silica microparticles inside the arrayed pores of a polystyrene film. Independent adjustments of the particle sizes and the pore sizes are carried out by varying the breath figure self-assembly process, free from the size-matching rule for a conventional “bead-in-pore” structure. The honeycomb structure not only provides free space but also demonstrates hydrophilic–hydrophobic wetting contrast favoring the accurate growth of additional components in each pore. The secondary subcomponents with different materials and dimensions could be synthesized in situ or crystallized by anchoring silica particles to form arrays of binary structures.