Optimal conditions for synthesis of TiO2 nanoparticles in semi-batch reactor

Titanium dioxide (TiO2) nanoparticles were synthesized from tetraethylorthotitanate (TEOT) dissolved in ethanol by using a semi-batch process in order to overcome difficulties in production of nanoparticles by a batchwise reaction. In this work, a statistical experimental design method was also used to find the effect of four parameters [R (=H2O/TEOT), hydroxypropylcellulose (HPC) as a dispersant, the feed rate of reactant, and reaction temperature] on the various properties of TiO2 particles. It was found that the optimal conditions for the preparation of monodispersed TiO2 nanoparticles with high yield and surface area were as follows: (R: 16, HPC: 0.0028 g ml−1, feed rate of reactant: 3.3 ml min−1, and reaction temperature: 28 °C). Experimental results measured by using the above optimal conditions were in agreement with theoretical data and the smallest particle size (∼10 nm in diameter) was obtained. In conclusion, the main parameters affecting the properties of TiO2 particles were decreased in the order of HPC>feed rate of reactant>R (=H2O/TEOT)>reaction temperature.