Highly stable- silica encapsulating magnetite nanoparticles (Fe3O4/SiO2) synthesized using single surfactantless- polyol process

We developed a new one-pot synthesis method for silica coated magnetite nanoparticles by way of a cheap- modified polyol process. In this reaction, polyethylene glycol was used as a solvent media and it has been found to play a key role to act as a reducing agent, stabilizer as well as a linker for silica coating, simultaneously. The Fe3O4/SiO2 sample prepared by this new method was compared with other seed Fe3O4 and Fe3O4/SiO2 samples synthesized through the modified Stober method and characterized using different analysis techniques such as transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, thermogravimetric analysis and Fourier transform infrared spectroscopy. The magnetic properties of the seed Fe3O4 and silica coated magnetite nanoparticles were studied by vibrating sample magnetometer at room temperature. The produced composite sample showed excellent stability against oxidation when annealed at 600 °C in presence of hydrogen gas. Thus, the facile new polyol process adopted in our study appears to be a promising route for synthesis of highly stable, hydrophilic silica coated magnetite nanoparticles.