Chemical "top-down" synthesis of amphiphilic superparamagnetic Fe3O4 nanobelts from exfoliated FeOCl layers.

A novel chemical "top-down" method has been employed to prepare tiny Fe3O4 nanobelts. Uniform Fe3O4 nanobelts were obtained by solvothermal reduction of exfoliated FeOCl layers with the assistance of high polar solvents and a PEO-PPO-PEO stabilizer. We also studied the superparamagnetic properties of Fe3O4 nanobelts, which exhibit a magnetic saturation value as high as ∼53 emu g(-1) at room temperature and a magnetic anisotropy constant up to 6.6 × 10(4) erg cm(-3). Furthermore the as-obtained product, which is amphiphilic and exhibits excellent dispersibility and redispersibility in most of the common solvents, could be readily used in various realms of biomedicine and biotechnology.