Patchy Silica Particles

Abstract

Patchy particles, or particles with anisotropic surface functionality, have various potential applications, for example as model systems or functional materials. For all these applications the formation of particles with a controlled number and relative positions of the patches is key. This research sets out to synthesise patchy silica particles and compare their patchiness to the crystal structure and crystal fraction of the colloidal crystals from which the patchy particles were formed. Patchy particles were synthesised by surface modification of a sintered colloidal crystal with 3-(trimethoxysilyl)propyl methacrylate (TPM). After redispersion, silica protrusions were grown on the non-modified patches. Syntheses were performed by varying the following parameters: sinter temperature, sinter time, particle size, particle concentration, surface modification, and the added amount of silica precursor. The crystal structure and crystal fraction of the colloidal crystal from which the particles were formed were investigated. Furthermore, patchy particles with a different number of patches and patchy particles with fluorescent patches were investigated.