Ferrofluids
Ferrofluids and magnetic particles for biomedical applications

Ferrofluids were first described by Rosensweig in 1966 . They are stable magnetic fluids composed of ferromagnetic nanoparticles between 5 and 12 nm in diameter, dispersed in a liquid phase (aqueous or organic). The synthesis of a magnetic dispersion generally takes place in two stages:

• synthesis of magnetic nanoparticles ;

• dispersing these particles in a medium compatible with the chemical nature of the nanoparticle surface.

In the case of charged nanoparticles, the dispersion medium is water. In an organic dispersion medium, it is essential to change the polarity of the particle surface using a surfactant or a polymer, and this...