关键词: 块状气凝胶, TiO₂, 制备, 溶胶-凝胶法, 超临界干燥

Abstract: Monolithic TiO₂ aerogels have been prepared from titanium n butoxide by sol-gel process and supercritical drying technique, and the structural properties of the aerogel samples have been characterized by means of SEM, TEM, XRD, IR, BETand pore distribution analysis. The results indicated that the optimum condition for preparing monolithic TiO₂ aerogels was n-[Ti(OC₄H₉)₄]: n-(C₂H₅OH): n-(H₂O): n-(HNO₃)=1:18.3:3.75:0.14. The final aerogels which consist of colloidal particles with diameters of about 5 nm were found to be with coherent uniform size and low density solid inorganic materials with porosity of about 90%, and contained mesopore in the range of 10-20 nm. The monolithic TiO₂ aerogels were of the pure amorphous form at room temperature, which would be converted into anatase and then into rutile by increasing the temperature of heat treatment.

Key words: Monolithic aerogel, TiO₂, Preparation, Sol-gel process, Supercritical drying