Size-controlled monodisperse hydrophobic and hydrophilic magnetite nanoparticles: One-pot synthesis, characterization, and the mechanism study

Depending on whether to add oleic acid in the reaction system, monodisperse magnetite nanoparticles with hydrophobicity and hydrophilicity are prepared by one-step “polyolthermal reaction”. Combined techniques of TEM, XRD, XPS and FTIR are used to characterize the obtained nanoparticles. The diameter of nanoparticles can be tuned easily by a simple change in the reaction time and the concentration of iron precursor. The method proposed here combines all the advantages of the high-temperature thermal decomposition method and the solvothermal process. Details about formation processes of magnetite nanoparticles are studied using UV–vis absorption spectrum. The result shows a different nucleation procedure and nucleation time for oil-soluble and water-soluble nanoparticles due to the presence of oleic acid. Magnetic properties of the prepared magnetite nanoparticles are also measured on vibrating sample magnetometer at room temperature.