Nucleation Process of the Silica Nanoparticles:Ⅰ.the Influence of Technological Conditions

Monodispersed silica nanoparticles are widely used in the fields of construction, daily chemistry, aerospace, catalysis and semiconductor. The preparation of silica nanoparticles includes two processes of nucleation and growth. The nucleation process is the foundation of spheri-city, uniformity and morphology of the silica nanoparticles, so the study of nucleation process is of great significance to the synthesis and the final products. In this work, the silica nanoparticles were prepared by the ion exchange method with the water glass as material. The concentration of the silicic acid, the addition rate of the monomer and the morphology of the particle during the nucleation process were stu-died in detail. The results show that the appropriate concentration of silicic acid is 5wt% and the addition time should be 10 h. Final size of silica nanoparticle under this condition is 21.8 nm. In the early stage of nucleation, there is no monodispersed nucleus, only silica gel with cross-linked network structure exis-ting. Monodispersed and spherical silica nuclei can be prepared with the concentration of silica acid and addition time, which provides the critical condition for the uniform growth of particles in the next stage. © 2022, Materials Review Magazine. All right reserved.