Preparation and Characterization of Chain-Like and Peanut-Like Fe3O4@SiO2 Core–Shell Structure

The size- and shape-controlled Fe3O4@SiO2 nanocomposites were successfully synthesized via the sol–gel method. The results showed that the size, shape, and property of the products were directly influenced by the amount of TEOS, and the concentration of water-based magnetic fluid in the coating process. The morphology and properties of the products were characterized by TEM, SEM, X-ray powder diffraction, IR and EDS. The Fe3O4@SiO2 composites with easily-controlled size arranged from 58 to 835 nm could be synthesized by adjusting the experimental parameters. When TEOS amount is 1 mL and the concentration of magnetic fluid were 30.0 and 10.0 mg/mL respectively, chain-like and peanuts-like well-dispersed Fe3O4@SiO2 particles with clear core–shell structure were obtained. These size- and shape-controlled Fe3O4@SiO2 composites may have potential application in the field of targeted drug delivery and MRI contrast agent.