Formation of crystalline nanosized titania in reverse micelles at room temperature

Shuttle-like crystalline TiO2 nanoparticles were synthesised by hydrolysis of titanium tetrabutoxide in the presence of acids in NP-5 (Igepal CO-520)-cyclohexane reverse micelle at room temperature. Pure rutile nanoparticles were obtained at appropriate acid concentrations. The effect of various reaction conditions, such as concentration and type of acid, water content, H2O/Ti molar ratio, and reaction time, on the formation, crystal phase, morphology, and size of the TiO2 particles was investigated. The acidity, the type of acid used, and the microenvironment of the reverse micelles are the key factors affecting the formation of rutile at room temperature. Prolonged reaction times and increasing the [H2O]/[NP-5] and [H2O]/[Ti(OC4H9)4] ratios leads to agglomeration of the particles. 24 refs.