Synthesis of raspberry-like monodisperse magnetic hollow hybrid nanospheres by coating polystyrene template with Fe3O4@SiO2 particles

In this paper, we present a novel method for the preparation of raspberry-like monodisperse magnetic hollow hybrid nanospheres with γ-Fe2O3@SiO2 particles as the outer shell. PS@Fe3O4@SiO2 composite nanoparticles were successfully prepared on the principle of the electrostatic interaction between negatively charged silica and positively charged polystyrene, and then raspberry-like magnetic hollow hybrid nanospheres with large cavities were achieved by means of calcinations, simultaneously, the magnetite (Fe3O4) was transformed into maghemite (γ-Fe2O3). Transmission electron microscopy (TEM) demonstrated that the obtained magnetic hollow silica nanospheres with the perfect spherical profile were well monodisperse and uniform with the mean size of 253 nm. The Fourier transform infrared (FTIR) spectrometry, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) provided the sufficient evidences for the presence of Fe3O4 in the silica shell. Moreover, the magnetic hollow silica nanospheres possessed a characteristic of superparamagnetic with saturation magnetization value of about 7.84 emu/g by the magnetization curve measurement. In addition, the nitrogen adsorption–desorption measurement exhibited that the pore size, BET surface area, pore volume of magnetic hollow silica nanospheres were 3.5–5.5 nm, 307 m2 g−1 and 1.33 cm3 g−1, respectively. Therefore, the magnetic hollow nanospheres possess a promising future in controlled drug delivery and targeted drug applications.

A facile method is presented for the preparation of raspberry-like monodisperse hollow hybrid nanospheres with γ-Fe2O3@SiO2 particles as the outer shell via sol–gel process.Figure optionsDownload high-quality image (168 K)Download as PowerPoint slideResearch highlights
► A facile method for preparing raspberry-like magnetic hollow nanospheres was developed.
► The Fe3O4@SiO2 particles were shapely coated on the surface of PS templates.
► The hollow nanospheres were well monodisperse and uniform with a size of 253 nm.
► The hollow nanospheres possessed large cavities and excellent magnetic properties.