Of Tio <sub> 2 </ Sub>, The Y <sub> 2 </ Sub> O <sub> 3 </ Sub> Micro-nanospheres And Its Composite Oxide Synthesis And Its Near-infrared Reflectance Performance

In this paper, TiO₂ precursor was prepared by sol-gel process with tetrabutyl titanate as raw material, then titanium oxide microspheres of different crystal forms were obtained from the precursor by different sintering temperatures. Y₂O₃ nanospheres were synthesized through homogeneous precipitation method, with Y(NO₃)₃, NaOH and urea as materials. TiO₂-Y₂O₃ composite coating was obtained by ball milling method from the samples prepared. The composition, structure, morphology and reflectance properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), TG Dynamic Stability Controln (TG-DSC), FE-scanning electronic microscope (FE-SEM). Various factors and the preparing method on the sample morphology was investigated, also, the growth mechanism of the spheres was studied. The main contents are as follows:1.With sol-gel method and surfactants as auxiliary, TiO₂ microspheres precursor of narrow dispersion were prepared, whose average diameter was 800nm. TiO₂ microspheres were obtained by proper heat treating. The size and morphology does not change after heat treatment. By controlling the temperature of heat treating, titanium dioxide microspheres of anatase and rutile type can be obtained. XRD, TG-DSC and SEM have been employed to analyzed the construction of product, reflection properties of the sample was determined by UV-VIS-NIR-spectrometer.2.With homogeneous precipitation method, and surfactants as auxiliary, precursor of different diameter were prepared. Y₂O₃ nanospheres of different particle size were obtained by proper heat treating.The diameter is between 40nm and 250nm. The size and morphology does not change after heat treatment. XRD, TG-DSC, FE-SEM and TEM have been employed to analyzed the construction of products, reflection properties of the sample was determined by UV-VIS-NIR-spectrometer.3.Disperse TiO₂ and Y₂O₃ prepared into water-borne or solvent acrylic resin respectively to carry coating experiments. The results show that the best filler for TiO₂ coating is the microspheres obtained at 900℃for 2h, the best filler of Y₂O₃ coating is the Y₂O₃ nanospheres which particle size is 180nm.4.With TiO₂ and Y₂O₃ as raw materials, Oily acrylic resin and hexamethylenetetramine as dispersant, TiO₂-Y₂O₃ composite coating was obtained by ball milling method。The effect of the dopant ratio, ball/powder weight ratio, milling time and the dosage of aerogel were investigated. UV-VIS-NIR-spectrometer was employed for the reflection properties of the coatings prepared. The optimum condition for the preparation of TiO₂-Y₂O₃ composite coating with best reflection properties was obtained, the preparation conditions follow the ratio with yttrium∶titanium =1:1, ball:paint=3:4, ball milling time for two hours.