SYNTHESIS AND CHARACTERIZATION OF MAGNETIC Fe3O4 NANOPARTICLES USING OLEIC ACID AS STABILIZING AGENT

Magnetic iron oxide nanoparticles (Fe3O4) provide multiple advantages for drug delivery application due to their inertness, non-toxicity, biocompatibility, and ease of detection as the diagnostic tool for contrast imaging in the human body. To protect against oxidation, preferably covalently bonded a surfactant for coating Fe3O4 is required. For this purpose, in the present study, oleic acid (OA) was applied to stabilize Fe3O4 magnetic nanoparticles via onepot-three-component reaction. Mild conditions as a well as simple reaction could be attributed to this method in producing Fe3O4-OA nanoparticles. The amount of oleic acid (OA) was studied to explore properties of the resulted nanoparticles. Infrared spectroscopy revealed that OA is chemisorbed via a carboxyl group onto the surface of the iron oxide nanoparticle and is coordinated symmetrically to the oxide atoms. Furthermore, there is a ligand exchange between –OH groups and –COO groups on the Fe3O4 nanoparticle surfaces. X-ray diffraction (XRD) spectra indicated that Fe3O4 phase was predominantly obtained beside small amount of γ-Fe2O3 phase. The average crystallite size of the synthesized Fe3O4 nanoparticles at different amount of OA was found in the range of 6.60 nm to 9.48 nm. Magnetic properties of the nanoparticles were determined by electron spin resonance (ESR). The gradient curve of ESR spectra revealed that Fe3O4 and OA-coated Fe3O4 nanoparticles possess significantly different magnetic properties.