Growth of SiO2 microparticles by using modified Stober method: Effect of ammonia solution concentration and TEOS concentration

The unique structural features and suitability of the SiO2 microparticles in different application areas have mobilized a worldwide interest in the last few decades. In this report a classical method known as the Stober method has been used to synthesize silica microspheres. These microparticles have been synthesized by the reaction of tetraethyl orthosilicate (Si(OC2H5)(4), TEOS)(silica precursor)with water in an alcoholic medium (e.g. ethanol) in the presence of KCl electrolyte and ammonia as a catalyst. It has been observed that the size of the microparticles closely depends on the amount of the TEOS and ammonia. A decrease in the size of micro particles from 2.1 mu m to 1.7 mu m has been confirmed as the amount of TEOS increases from 3.5ml to 6.4ml respectively. In similar way a decrease in the diameter of the micro particles from 2.1 mu m to 1.7 mu m has been observed with increase in the ammonia content from 3ml to 9ml.