Synthesis of surfactant free SiO2 nanoparticles via emulsion method

We demonstrate a facile method for the synthesis of monodisperse SiO₂ nanoparticles through simple emulsion method without the use of any surfactant and toxic solvents. The effect of concentration of tetraethyl orthosilicate, ammonia and water on final size of nanoparticles was studied. These particles were characterized by X- ray diffraction, scanning electron microscopy and transmission electron microscopy. Without the use of any surfactant, SiO₂ nanoparticles of size 30 ~ 90 nm are synthesized by incisively controlling the amount of ammonia and water.