In this paper, we report a new route to synthesize novel magnetic hollow silica nanospheres (MHSNs) using polystyrene particles as sacrificial templates, and TEOS and Fe 3O 4 as precursors. TEM, EDS, XRD, and SQUID were applied to characterize MHSNs. TEM and EDS results show that the MHSNs consist of about 200 nm of hollow cores and ∼35 nm shells with ∼10 nm of Fe 3O 4 nanoparticles embedded. The polystyrene beads were successfully removed by immersing the as-prepared silica nanocomposite in a toluene solution. XRD results demonstrate that the Fe 3O 4 magnetic nanoparticles still keep spinel structure even heated at low temperature. The surface status of the polystyrene beads and Fe 3O 4 nanoparticles has an important effect on the formation of the MHSNs. The MHSNs present a superparamagnetism at room temperature by SQUID measurement. The MHSNs have potential applications in biosystem and nanomedicine.
Journal of Magnetism and Magnetic Materials
- Pub Date:
- April 2007
- Studies of specific magnetic materials;
- Nanoscale materials and structures: fabrication and characterization;