常压干燥制备有机复合韧性硅气凝胶

Preparation of organic composite tenacious silica aerogels via ambient pressure drying

以甲基三甲氧基硅烷(MTMS)和N-氨乙基-γ-氨丙基-三甲氧基硅烷(ATAPTES)为硅源,间苯二酚和甲醛为有机增强体,采用溶胶-凝胶法通过常压干燥制备了有机韧性SiO 2气凝胶。研究了MTMS与ATAPTES、甲醛与间苯二酚摩尔比对复合气凝胶结构和性能的影响。采用N 2吸附脱附等温线、SEM、FT-IR及压缩测试等方法对韧性气凝胶进行了表征。结果表明,甲醛与间苯二酚摩尔比为4时,气凝胶孔径分布范围较宽,总孔容积0.15~0.40 cm ^3/g,比表面积5~70 m ^2/g,最大形变率可达50%,对有机溶剂的吸附量可达自身质量的7~11倍。甲醛与间苯二酚摩尔比为2时,气凝胶孔径主要分布范围3~10 nm,总孔容积0.52~0.53 cm^ 3/g,比表面积110~120 m 2/g,有机复合硅气凝胶柔韧性较小,最大形变率为10%。

Organic composite tenacious SiO 2 aerogels were prepared by sol-gel method using methyltrimethoxysilane(MTMS)and N-(b-Aminoethyl)-γ-aminopropyl-trimethoxysilane(ATAPTES)as silicon source,resorcinol and formaldehyde as organic reinforcements.The effects of molar ratio of MTMS and ATAPTES,resorcinol and formaldehyde on the structure and properties of aerogels were studied.The microstructure and properties of the obtained tenacious aerogels were characterized by N 2 adsorption-desorption isotherm,SEM,FT\|IR and compression tests.The results show that the pore size distribution of the composite aerogel is wide,with the pore volume being 0.15-0.40 cm 3/g and specific surface area being 5-70 m 2/g when molar ratio of resorcinol and formaldehyde is 4.The maximum deformation rate can reach 50%,and the adsorption capacity for organic solvent can reach 7-11 times of the composite aerogel’s own weight.Whereas,the pore size of the composite aerogel is mainly distributed in 3-10 nm,with the pore volume being 0.52-0.53 cm 3/g and specific surface area being 110-120 m 2/g when molar ratio of resorcinol and formaldehyde is 2.The composite aereogel exhibits small flexibility with the maximum deformation rate being 10%.