Self-assembly of colloidal polymers from two-patch silica nanoparticles

We report the formation of colloidal polymers consisting of disk-like silica nanoparticles (NPs) with polystyrene (PS) chains at the bottom of their two cavities assembled through reduction of the solvent quality for the PS chains and linked by hydrophobic associations. We show that this NPs assembly exhibits a two-stage process involving reaction-controlled polymerization and diffusion-controlled polymerization. Colloidal polymer networks are produced by the incorporation of three-patch NPs, which serve as branching points between the colloidal chains. By co-assembling preformed homopolymers composed of patchy NPs of different sizes or surface chemical groups, block copolymers are also achieved. This study provides insight into the process of self-assembly of two-patch NPs by precisely designing the components to generate colloidal analogues of linear macromolecular chains.