Synthesis and property studies of Iron Oxide Nanoparticles

• Main Authors: Wen Ming Chin, 溫明鏡
• Other Authors: Tai Ming Fong
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/85307413029076554857

碩士 === 國立中正大學 === 物理系 === 91 === The main focus is to prepare magnetic iron oxide nanoparticles by decomposition of organmetallic precursors. We choose Fe(CO)5 as the organometallic precursor together with different stabilizing agents were dissolved in organic solvent. γ-Fe2O3 metal oxide nanoparticles were then obtained through the reflux of the solution. The shape and the size of thus synthesized nanoparticles were analyzed by transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and X-ray powder diffractometer (XRD). The magnetic properties of γ-Fe2O3 nanoparticles were studied by using virbration sample magnetometer to measure the hysteresis loop with applied magnetic field 12000 oersted at room temperature at first and by using high magnetic field measurement system (OXFORD MagLabAC) to measure the hysteresis loop of γ-Fe2O3 nanoparticles at low tempaerature and the magnetization of nanoparticles on fixed applied magnetic field with changing temperature. We discovered that the sizes of nanoparticles were varied in associated with the with molar ratios between Fe(CO)5 and oleic acid. The nanoparticle sizes can be controlled in a range of 4.7 0.9 nm to 7.7 1.6 nm. The effect of additional surfactants particle size up to11.7 2.0 nm with CTAB added. Further more, the additional stabilizer of polyethylene imine (PEI) changes by the increase of particle sizes to 30.9 4.2 nm via 1 hour reflux. Meanwhile, the particle sizes decreases with increasing reflux time. The saturated magnetization of γ-Fe2O3 nanoparticles were formed to be increased by decreasing particle sizes. 4.7 0.9 nmγ-Fe2O3 nanoparticles is 8.21 emu/g and that for the size of 7.7 1.6 nm is 3.62 emu/g. The saturated magnetization increases by a wide margin after adding PEI, while the saturated magnetization of 30.9 4.2 nm γ-Fe2O3 nanoparticles is 23.31 emu/g. From the hysteresis loop studies, particles are paramagnetic at room temperature and they exhibited superparamagnetic phenomenon. They become ferrimagnetism at low temperature. The increase of the coercive force is due to thermal vibration. Our preliminary studies of these magnetic nanoparticles in gene transduction of retroviral vectors on biomedicine showed a promising enhancing effect. It will be investigated further in the near further.