Preparation Of Titanium Dioxide Microspheres

Titanium dioxide is a N-type semiconductor materials, which is widely used in sensors, dielectric materials, paints, cosmetics, antimicrobial agent, sewage treatment and so on for its wet sensitive, gas sensing, dielectric effect, photoelectric effect, photochromic and superior photocatalytic properties.In recent years, three-dimensional structure of titanium dioxide, because of unique structure, performance, the use of a wide range of subject and many other characteristics is favored by domestic and foreign researchers. Titanium dioxide microspheres is one form of three-dimensional structure titanium dioxide, it becomes one of the the most research point at home and abroaddue to the state of near-size and unique appearance. At present, the preparation method of titanium dioxide is still the focus of the researchfield. Therefore, no template solvent evaporation and spreading membrane calcine method were adopted to prepare titania microspheres, and scanning electron microscopy (SEM) and X-ray diffraction (XRD) and other means of characterization methods were used to study its impacts and formation mechanism. The main results are as follows:(1) No template solvent evaporation method was adopted to synthesize titanium dioxide microspheres for the first time, and their particle size is in the range of 1-2μm. This method can avoid causing the product of post-processing difficulties, and other shortcomings. SEM was adopted to study the appearance of the synthesized microspheres which is affected by the solvent quality, the solute concentration, temperature, oil -water bath, stirring speed and so on. And XRD was used to characterize different calcination temperature treatment of titanium dioxide microspheres. The results showed that the solvent concentration can affect the microspheres particle size; and when the reaction temperature is higher, the microspheres not to be more homogeneous; and when the steam is not enough, the production titanium dioxide microspheres particle size is uneven, the appearance is not so good; stir would undermine the formation of spherical titanium dioxide; the microspheres at room temperature, 500℃, 800℃, are no stereotypes, anatase and rutile, respectively. In addition, the prepared microspheres formation mechanism of no template-solvent evaporation is preliminary speculated. The possible mechanism for: under certain temperature, the precursor first contact and reacts with water molecules in the air at gas-liquid interface, and form titanium dioxide; Accompanied by a volatile solvent and gas-liquid interface reaction of the turn, and the titanium dioxide form nuclear, and grew up the final formation of microspheres.(2) Using the spreading membrane calcine method to grow TiO₂ microspheres. The study results showed that particle size of the grown microspheres is 1-2μm, and the heat treatment temperature and time has the varying degree influence to the product. Reaction temperature on the formation of microspheres has an impact. Heat Treatment little effect on the reaction time, the growth over time, the particle size was no significant change when microspheres growth to 1-2μm, for the surface is basically stable. The prepared microspheres formation mechanism of no template-solvent evaporation is preliminary speculated. The possible mechanism for: at high temperature conditions, ethanol firstly evaporate to form thin film of n-butyl titanate, and with the temperature increase gradually, the film fuse and curled into titanium dioxide, and grew into the nucleation, and form microspheres at last.