Synthesis of Magnetite Nanoparticles of Different Size and Shape by Interplay of Two Different Surfactants

Given the central role that nanoparticle size and shape play in many fundamental applications for designing functional materials, fine control of the synthesis has been intensively pursued. A simple one-step method for obtaining monodisperse nanoparticles over a large size range with shape control has not yet been reported. Here, we propose a simple method to control the morphology of magnetite nanoparticles by regulating the amount of non-selective binding surfactant by simply altering the ratio of oleylamine and fatty acid. With this approach, we were able to synthesize magnetite nanoparticles with sizes ranging between 6 +/- 1 and 176 +/- 20 nm and to select between more rounded or faceted shapes.