Fe₂O₃ Nanoparticles Coated in a SiO₂ Shell by Microemulsion Method

Abstract

Mixing elements at nanoscale range can offer exciting possibilities of novel materials with composition, structure and properties quite different from those in the bulk. Fe₂O₃ nanoparticles embedded in a surrounding silica shell were prepared via surfactant – assisted process by using dodecyl-4-lauryl ether (Brij 30) as oriented template, followed by thermal treatment. The nanoparticles are formed by the precipitation reaction of ferrous and ferric salts with ammonium hydroxide into water-in-oil microemulsion. The hydrodynamic radius of microemulsion droplets and coated nanoparticles were measured by dynamic light scattering. Their structural properties have been studied by FT-IR spectroscopy, thermogravimetric analysis and atomic force microscopy.

Keywords:

• Fe₂O₃ & SiO₂ nanoparticles
• water-in-oil microemulsion

Acknowledgments

This article was supported by the Romanian National CEEX POSTDOC program, project No 8/2004. The authors gratefully acknowledge its financial support.