Tetraethyl orthosilicate and methyltriethoxysilane were used as copolymerized silicon sources,and N,N-dimethylformamide was added as a chemical additive for drying control to prepare silica sol by acid catalysis.Subsequently,the shading agent SiC was added and mixed evenly with the silica sol,and then aged under alkaline conditions to obtain the SiC-doped modified double silicon source system SiO2 sol.Finally,SiC-doped modified SiO2 aerogel was obtained by post-treatment processes such as hydrophobic modification and solvent exchange under atmospheric pressure drying.The microstructure and properties,surface morphology,material composition and pore structure of SiO2 aerogel with double silicon source system were investigated.The effects of different SiC doping amount and different temperature conditions on the thermal insulation properties of SiO2 aerogel were further analyzed.The results showed that the thermal conductivity of SiO2 aerogel doped with SiC could be as low as 0.0482W/(m·K) at 700℃,and it had good high temperature insulation performance.
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基金资助
陕西国防工业职业技术学院2022年度科研计划项目(Gfy22-03)
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