SYNTHESIS OF MONODISPERSED SILICA POWDERS .2. CONTROLLED GROWTH REACTION AND CONTINUOUS PRODUCTION PROCESS

The present paper will describe the preparation of monodispersed silica particles by a controlled growth process. This procedure has several advantages compared with the original Stober (batch) process. A simple calculation allows seeds of a given size to be grown exactly to a pre-set final particle size. Spherical and exceptional monodispersed particles of up to 3.6 mu m in diameter and a very high (particle) mass fraction of up to 10 vol.% silica could be prepared by this process. Moreover, a simple tube reactor is shown, which allows those particles to be produced on a continuous basis.