Preparation of Al2O3-SiO2-ZrO2 Composite Aeroels By Sol-Gel Method

Aerogels that have fascinating such as high porosity, large surface aera, low density and low thermal conductivity have been used in numerous application fields including microfilters, adsorbents, controlled release of drug, especially for thermal insulation and catalyst or support of catalysts. The Al2O3-SiO2-ZrO2 composite aerogel with low density were synthesized by Sol-gel technology and supercritical drying method. AlC13·6H2O, ZrOCl2·8H2O and tetraethoxysilane(TEOS) was introduced as precursor, the mixed solution of water and ethanol were chosen as reaction medium, and propylene oxide was added as gelation promoter. Changing the molar ratio of Al:Si:Zr , the kinds and content of crystal phases of aerogel composite could  be different, which may lead to a variety of microstructure of aerogel. The effects of heat treatments on the surface nanoscale topography and microstructure of aerogel composite were also analyzed. The morphology and structures of as-prepared and calcined aerogels are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), raman spectroscopy, BET surface area analysis, thermogravimetric and differential scanning calorimetry analysis (TG-DSC).