Document Type: Research Paper
Silica nanoparticles were synthesized by chemical methods from tetraethylorthosilicate (TEOS), polyethylene glycol 5% and hydrochloric acid 0.001 N. The sol-gel process was applied for the preparation of nano silica gel. This method is hydrolysis and condensation reactions of TEOS as precursor of silica. The optimal synthesis conditions for the preparation of silica nanoparticles were obtained and the produced silica nanoparticles were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicated that the silica nanoparticles were successfully formed. The prepared samples change from amorphous to α-crystallite phase. The XRD analysis indicated the amorphous structure of the synthesized silica nanoparticles while the SEM and TEM images exhibited monodispersedNano sized silica particles with a size about 34 nm. In this study, the soft process of sol-gel reaction is favourable from a view point of energy conservation. Additionally, the advantages of this technique were the purity of products and ability to control nanometer sized internal structure.