Spherical SiO2 particles

摘要

Highly monodispersed nonporous spherical SiO2 particles are prepared having mean particle diameters between 0.05 and 10 mu m with a standard deviation of not more than 5% and a method for the preparation of such particles. The particles can be produced by a two step process wherein first a sol of primary particles is prepared by hydrolytic polycondensation of tetraalkoxysilanes in an aqueous/alcoholic ammoniacal medium. The SiO2 particles are then converted to the desired particle size by a continuous measured addition of tetraalkoxysilane or organotrialkoxysilane controlled by the extent of the reaction. The SiO2 particles produced by this process are particularly useful as sorption material in chromatography.