Abstract
A hydrothermal synthesis process for preparing crystalline magnetite （Fe3O4） nanoparticles was statistically analyzed to control the particle size, using response surface methodology （RSM） based on design of experiments （DOE）. The influence of the experimental parameters （initial ferrous/ferric ion molar ratio, initial concentration of ferrous ions, and heating time） and their interactions on the particle growth was evaluated through the analysis of variance （ANOVA） for the dynamic light scattering diameter. Furthermore, the multiple linear regression analysis （MLRA） was performed, and then the three-dimensional response surface plots were obtained. The particle size was found to be affected by the experimental parameters, in particular, the interaction between the ferrous/ferric ion molar ratio and the concentration of ferrous ions, suggesting that the particle growth mechanism is altered depending on the amount of ferrous ions. The particle size can be successfully controlled to a given target level using the obtained analysis results.
