Key Parameters for Scaling up the Synthesis of Magnetite Nanoparticles in Organic Media: Stirring Rate and Growth Kinetic

The synthesis of magnetic nanoparticles by thermal decomposition in organic media has been studied in this work. The analysis was focused on external parameters, like stirring rate and reaction growth kinetics, given that they are crucial for scaling up the synthesis of magnetic nanoparticles. These parameters have been shown to control magnetite nanoparticle size and size distribution. Magnetite nanoparticles were prepared by thermal decomposition of iron(III) acetylacetonate in 1-octadecene using different stirring rates. At 100 rpm, the largest particle size was achieved, ca. 10 nm, which showed superparamagnetic behavior at room temperature. Growth kinetics were studied at a stirring rate (r) of 100 rpm. Data showed that during magnetite synthesis, particle growth exhibits a sigmoidal behavior and a final Oswald ripening process. Data were fitted to the double Boltzmann function.