Monodisperse Silica Microsphere with Extremely Large Specific Surface Area: Preparation and Characterization

Monodisperse SiO₂ microspheres are widely used in catalysis, separation, adsorption, and drug delivery. Their particle size, uniformity, and specific surface area are crucial for these applications. This study reports the novel preparation of monodisperse SiO₂ microspheres using cetyltrimethylammonium bromide as the template agent, employing hexadecylamine serving concurrently as a pore-expanding agent and catalyst. By controlling the reactant quantities and reaction conditions, we achieved monodisperse SiO₂ microspheres with tunable particle sizes ranging from 800 nm to 2.5 μm with exceptionally large specific surface areas. It is worth mentioning that microspheres with a particle size of 2 μm and extremely uniform size distribution were produced at room temperature. Excitingly, it has a BET specific surface area of 1543 m²/g. Various effects on the preparation of the microspheres were investigated in detail, and the growth mechanism of these microspheres was elucidated.