Highly stable-silica encapsulating magnetite nanoparticles (Fe ₃O₄/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 Fe₃O ₄ 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 Fe₃O ₄ 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.