New Process For The Preparation Of Monodispersed, Spherical Silica Particles

A new method is presented for preparing highly monodispesed silica particles using a two-stage semibatch/batch hydrolysis reaction of Si(OC2H5)4. The slower rate of hydrolysis of the tetraethylorthosilicate (TEOS) that occurred during the semibatch process resulted in larger silica particles with a higher yield and narrower size distribution. This was in direct contrast to the batch process. In addition, the ability of four different mixed processes to produce silica particles with good packing density, narrower particle-size distribution, and higher yield were evaluated.