Size control of monodisperse silica particles by modified Stöber method

Monodispersed silica spheres were prepared by an effective method, which an ethanolic solution of tetraethyl orthosilicate (TEOS) was continuously supplied to the reaction mixture containing KCl electrolyte, water, TEOS, ethanol and ammonia. The particle size of the silica spheres ranged from 2.0 to 4.5 µm. In addition, the effects of reaction conditions such as temperature and amount of ammonia on microsphere morphology were studied.