Preparation of Fe3O4/SiO2 Core/Shell Nanoparticles with Ultrathin Silica Layer

We successfully synthesized Fe3O4/SiO2 nanoparticles with ultrathin silica layer of 1.0 +/- 0.5 nm that was fine controlled by changing concentration of Fe3O4. Among various reaction conditions for silica coating, increasing concentration of Fe3O4 was more effective approach to decrease silica thickness compared to water-to-surfactant ratio control. Moreover, we found that concentration of the 1-octanol is also important factor to produce the homogeneous Fe3O4/SiO2 nanoparticles. The present approach could be available to apply on preparation of other core/shell nanoparticles with ultrathin silica layer.