▎ 摘　　要

NOVELTY - Preparing high specific surface area and strong hydrophobic graphene oxide/silicon dioxide composite aerogel at normal pressure comprises (i) mixing tetraethyl orthosilicate, ethanol, and water, adding dilute hydrochloric acid for adjusting pH to 2-4, stirring uniformly, reacting at room temperature for 8-24 hours, and adding N,N-dimethylformamide dropwise, (ii) adding ethanol solution of aminopropyltriethoxysilane to solution obtained in the step (i) until the pH is 5-6.5, adding graphene oxide hydrosol, ultrasonically treating for dispersing graphene oxide uniformly, continuously adding ethanol solution of aminopropyltriethoxysilane to a pH of 7-8.5, and ultrasonically treating until forming graphene oxide/silicon dioxide composite alcohol gel, (iii) firstly aging formed graphene oxide/silicon dioxide composite alcohol gel in air, then aging in water/ethanol mixed solution, and tetraethyl orthosilicate/ethanol mixed solution, and (iv) dissolving aged alcohol gel in isopropyl alcohol. USE - The method is useful for preparing high specific surface area and strong hydrophobic graphene oxide/silicon dioxide composite aerogel at normal pressure. ADVANTAGE - The method: replaces traditional alkaline catalyst with silane coupling agent, aminopropyltriethoxysilane as silicon source which contains basic group amino group; chemically bonds with acidic carboxy group in graphene oxide; enhances adhesion; greatly reduces gel formation time; and obtains graphene oxide/silica aerogel having high specific surface area, strong hydrophobicity, and low thermal conductivity. DETAILED DESCRIPTION - Preparing high specific surface area and strong hydrophobic graphene oxide/silicon dioxide composite aerogel at normal pressure comprises (i) mixing tetraethyl orthosilicate, ethanol, and water, adding dilute hydrochloric acid for adjusting pH to 2-4, stirring uniformly, reacting at room temperature for 8-24 hours, and adding N,N-dimethylformamide dropwise, (ii) adding ethanol solution of aminopropyltriethoxysilane to solution obtained in the step (i) until the pH is 5-6.5, adding graphene oxide hydrosol, ultrasonically treating for dispersing graphene oxide uniformly, continuously adding ethanol solution of aminopropyltriethoxysilane to a pH of 7-8.5, and ultrasonically treating until forming graphene oxide/silicon dioxide composite alcohol gel, (iii) firstly aging formed graphene oxide/silicon dioxide composite alcohol gel in air, then aging in water/ethanol mixed solution, and tetraethyl orthosilicate/ethanol mixed solution, (iv) dissolving aged alcohol gel in isopropyl alcohol, or n-hexane solvent for replacing water and ethanol in alcohol gel, (v) placing the gel obtained in step (iv) in a mixture of trimethylchlorosilane/n-hexane for hydrophobically modifying, (vi) removing modified gel by hydrochloric acid, and trimethylchlorosilane present in gel with n-hexane solution to obtain alcohol gel, and (vii) drying the alcohol gel under normal pressure to obtain the product.