Synthesis of Monodisperse Polystyrene@Vinyl-SiO₂ Core–Shell Particles and Hollow SiO₂ Spheres

This paper presents a scalable method of preparing highly monodisperse core–shell particles and hollow spheres, and their application in fabricating colloidal crystals. By using polystyrene (PS) particles as the template and vinyltrimethoxysilane as the precursor, the core–shell particles could be obtained via direct growth of vinyl-SiO 2 hybrid material on the negatively charged PS template. This method has two interesting characteristics. The first is the tunable shell thickness (from 10 to 170 nm) combined with a low polydispersity (smaller than 3%). Second, the method is simpler than traditional ones, which use surface modified PS as template to get a uniform coating. Furthermore, the core–shell particles could be converted into hollow SiO 2 spheres by removing the PS cores in a calcination process. Both the PS@vinyl-SiO 2 particles and the hollow SiO 2 spheres could be self-assembled into three-dimensional colloidal crystals, because the resulting particles are highly monodisperse and suspensible.