Size control of monodisperse nonporous silica particles by seed particle growth

Monodisperse nonporous silica particles were prepared by sol-precipitation via seed particle growth method, and the particle size, which varied from 1.0 to 4.7 μm, was strictly controlled in our experiment. The formation of secondary particles, which resulted in a multimodal distribution of particle size, was suppressed by changing tetraethoxysilane (TEOS) concentration and reaction temperature. Furthermore, the effect of adding small amounts of electrolyte to the hydrolysis mixture was examined.