TiO2 nanoparticles were prepared by a sol-gel method using TiCl4 as a precursor. The effect of the TiCl4/H2O molar ratio and DBS/ethanol (two important parameters in this process) on the particle size and structure of the samples were studied. The structure and morphology of the nanoparticles were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. A systematic study was made by using the results of Design-Expert software. The optimum ratio of TiCl4/H2O and DBS/ethanol, to achieve the smallest particle size and the highest rutile content, were studied. Results showed that a lower TiCl4/H2O molar ratio led to smaller nano particles and that this goal is achieved for the lowest TiCl4/ H2O molar ratio and intermediate DBS/ethanol values.

Keywords: TiO2 nano pigment, sol-gel method, TiCl4 precursor.