Gram-scale fabrication of patchy nanoparticles with tunable spatial topology and chemical functionality

Patchy particles, defined as particles with one or more well-defined patches, have attracted much attention due to their anisotropic and directional interactions. The anisotropic nature of the patchy particle surface enables a certain degree of control over the assembly process. Enormous efforts have been carried out to design and explore the properties of patchy particles and their collective behaviour. However, the techniques to fabricate patchy particles are still limited in terms of tunability and scalability. In this work, an effective method of fabricating patchy particles with tunable spatial topology and chemical composition of patches is presented. The number, distribution and size of the patches can be tailored by adjusting the packing of the colloidal particles and the processing condition. The active secondary reaction on the polydopamine (PDA)-coated surface and silica surface could functionalize the obtained patchy particles with desired properties to meet different requirements. As a proof of principle, the PDA-coated patches were modified with thiol-based dye via the Michael reaction and the silica surfaces were functionalized with amine-terminated alkoxysilanes via the silane coupling reaction have been demonstrated. Furthermore, the unique properties of PDA, such as reductive ability, powerful adhesive capability and carbonizable feature, have also been proven to fabricate metallic nanoparticle-decorated patchy particles and anisotropic carbon nanocapsules. The well-defined patchy particles are templated from colloidal crystal and their gram-scale fabrication is easily achieved. These results indicate that our strategy will help access the transformative potential of patchy particles in the rational design and large-scale production of functional materials.