Preparation of Monodisperse Iron Oxide Nanoparticles via the Synthesis and Decomposition of Iron Fatty Acid Complexes
1 Department of Mechanical Engineering, National Cheng Kung University, Tainan, 701, Taiwan, ROC
2 Nanomaterials Laboratory, Far East University, Hsing-Shih, Tainan County, 74448, Taiwan, ROC
3 Department of Power Mechanical Engineering, National Taitung Junior College, Taitung County, 95045, Taiwan, ROC
Nanoscale Research Letters 2009, 4:1343-1350 doi:10.1007/s11671-009-9403-xPublished: 30 July 2009
Iron fatty acid complexes (IFACs) are prepared via the dissolution of porous hematite powder in hot unsaturated fatty acid. The IFACs are then decomposed in five different organic solvents under reflux conditions in the presence of the respective fatty acid. The XRD analysis results indicate that the resulting NPs comprise a mixture of wustite, magnetite, and maghemite phases. The solvents with a higher boiling point prompt the formation of larger NPs containing wustite as the major component, while those with a lower boiling point produce smaller NPs with maghemite as the major component. In addition, it is shown that unstable NPs with a mixed wustite–magnetite composition can be oxidized to pure maghemite by extending the reaction time or using an oxidizing agent.