Preparation of the Silica Micro-Spheres by Chemical Precipitation Process

Silica micro-spheres were prepared from sodium silicate at room temperature with ethyl acetate as the precipitant. The effect of process parameters on the yield and the morphology of SiO2 powders was systematically investigated and the optimum reaction condition was confirmed as follows: the concentration of sodium silicate was 0.6 mol/L, the total addition amount of the blend surfactants of PEG-1000 and sodium dodecyl benzene sulfonate (SDBS) was 2.1% and the blend ratio was 20:1, the addition amount of ethanol and ethyl acetate were 5.0% and 8.0%, respectively, the stirring rate was 600 rpm and the reaction time was 4.0 hours. The average particle size was 400 rim and the yield was 93.8%.The product was characterized by scanning electron microscope, Infrared Spectroscopy, and X-ray powder diffraction.