Production of Iron Oxide Nanoparticles by Co-Precipitation method with Optimization Studies of Processing Temperature, pH and Stirring Rate

Iron Oxide Nanoparticle, maghemite (γ-Fe2O3) has received great interest and extensively used in biomedical field. Optimization studies were carried out in the production of γ-Fe2O3 nanoparticles by using co-precipitation method. Iron (II) chloride and iron (III) chloride were used as precursors which are dissolved in distilled water followed by centrifugation, drying and grinding process in order to obtain dried dark brown precipitated γ-Fe2O3 powder. The effect of different processing temperature (30 to 70°C), pH (10 to 12) and stirring rate (300 to 700rpm) towards crystallite size of γ-Fe2O3 were investigated by using Response Surface Methodology (RSM) and Central Composite Design (CCD). Based on analysis of variance (ANOVA), the determination coefficient, R² obtained was 0.9890 where stirring rate was the parameter that affected the most on the crystallite size. Optimization processing condition that produce smallest crystallite size of 7.3657 nm was 50 °C, pH 11.40 and 550 rpm by using Design of Expert software (DOE). Characterization of γ-Fe2O3 powder samples were evaluated by using different analytical tools such as Fourier Transform Infrared (FTIR), X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). Iron oxide group (Fe-O), hydroxyl (OH-) group and carbon dioxide (CO2) were identified in FTIR spectrum. The characteristic peak occurring at 2θ = 35.4° indicated presence of γ-Fe2O3 in the samples. The γ-Fe2O3 particles appeared generally in spherical shape in SEM analysis.