Abstract:
Top down and bottom up are two fundamental routes for the formation of magnetite nanoparticles (MNPs). These routes are generally utilized for producing technologically and economically significant MNPs. This review discusses the synthesis of MNPs and outlines methods of preparation that allow control over the size, morphology, surface treatment and magnetic properties of the nanoparticles. In the past, long grinding of bulk magnetite in the presence of stabilizing surfactants produced the first accepted ferrofluid containing MNPs. Such mechanogrinding methods were inherently time consuming and costly. Currently, perhaps the most commonly accepted approaches for creating MNPs concentrate around different forms of coprecipitation, microemulsion, biological nanoreactors, sol-gel and polyol methods. Various additional methods also exist for the controlled synthesis of MNPs including ultrasound irradiation (sonochemical synthesis), spray and laser pyrolysis.
