Preparation of Silica-Based Inorganic Capsule Shell via a Novel Emulsion-Sol-Gel Route

Abstract

NH₄OH was directly adopted as water phase and catalyst to prepare the silica shell, hexane and Span 80 were respectively adopted as oil phase and emulsifier to prepare water-in-oil emulsion. TEOS was adopted as the silica source, then the silica shell can be obtained through the sol-gel route at the interface of emulsion. Scanning electron microscope and X-ray diffraction were chosen to investigate the morphological and crystallized properties of samples. Results reveal that the morphology of capsule experienced the regular-irregular-regular-irregular transformation and hollow capsule can be obtained when the ratio of water phase to oil phase is 1:6. Furthermore, a schematic model of the experiment is proposed.