Highly Dispersed Iron Oxide Nanoparticles Synthesized by Solvothermal Method Adding Electrostatic Stabilizers

Magnetite nanoparticles (Fe₃O₄) in the range of submicrometer in diameters were prepared by modified solvothermal process adding electrostatic stabilizers to be applied for biomedical applications. Added electrostatic stabilizers could prevent the magnetic particles from agglomerating and slow down the reaction rate so that the size of Fe₃O₄ nanoparticles could be controlled. The average diameter of magnetic nanoparticles synthesized in the presence of different electrostatic stabilizers (citrate, didodecyldimethylammonium bromide, and polyethylene glycol) was in the range of 150-350 nm. All of the prepared samples exhibited sufficiently high saturation magnetization Ms value of 60-73 emu/g showing superparamagnetic behavior. They could also be easily redispersed in water after magnetic collection.