Preparation method of high-temperature-resistant and hydrophobic SiO2 aerogel felt

The invention belongs to the field of preparation processes of nano porous materials and relates to a preparation method of hydrophobic SiO2 aerogel felt resistant to high temperature (higher than or equal to 350 DEG C). A sol-gel method is adopted, wet gel is prepared from an organic silicon source serving as a silicon source, ethanol serving as a solvent, acid and alkali serving as catalysts as well as methyl sodium silicate and potassium methyl silicate serving as surface modifiers, and the high-temperature-resistant and hydrophobic modified SiO2 aerogel felt is obtained after the wet gel is subjected to aging, solvent displacement, supercritical drying and heat treatment. The prepared high-temperature-resistant and hydrophobic SiO2 aerogel felt can be used for a long time at the high temperature of 350 DEG C or above, keeps the hydrophobic effect and has low density, large specific surface area, high strength, high-temperature resistance, a good hydrophobic property and other excellent performance, and th