Effect of stirring speed on particle dispersion in silica synthesis

The particle size distribution of nanoparticles is an important indicator and has a crucial impact on their applications. In this work, we investigated the effect of stirring speed on particle size and size distribution during the synthesis of SiO2 nanoparticles and quantified the polydispersity index (PDI) for the first time. Our results showed that there is an approximate relationship between the stirring speed and the PDI. At a stirring speed of 400 rpm during the Stöber reaction, the PDI of SiO2 nanoparticles reached a minimum value of 0.027, with a diameter of 90 nm, indicating excellent particle dispersion and potential drug delivery applications.