Ultrasonic Wave Assisted Preparation and Properties of SiO_2 Aerogels by Fractional Modification

摘要

In this study, hydrophobic SiO_2 aerogel was prepared through fractional hydrophobic modification and ambient pressure drying of the raw material, tetraethoxysilane (TEOS) under ultrasonic wave and using trimethyl chlorosilane as modifier and acid catalyst in the process of sol-gel and acid-base catalysis. SiO_2 aerogels were analyzed and compared using scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller analysis method, Fourier transform infrared spectroscopy, X-ray diffraction. The results indicate that by adopting the ultrasonic wave, the specific surface area of SiO_2 aerogels was 801.71 m~2/g. Pore distribution in micro-pore range was 0.5-1 nm. Pore distribution in meso-pore range was 2.0-20 nm. The hydrophobic SiO_2 aerogels with the hydrophobic angle at 160° displayed super hydrophobicity.