添加三甲基乙氧基硅烷制备耐高温硅/铝复合气凝胶  

Preparation of Heat-Resistant Silica/Alumina Composite Aerogel by Adding Trimethylethoxysilane

作　　者：王文琴[1] 张志华[1] 祖国庆[1] 沈军[1] 周斌[1] 姚献东 

机构地区：[1]同济大学波耳固体物理研究所上海市特殊人工微结构材料与技术重点实验室,上海200092 [2]纳诺科技有限公司,绍兴312000

出　　处：《无机化学学报》2016年第1期117-123,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.51172163;U1230113);国家科技支撑计划(No.2013BAJ01B01);国家高技术研究发展计划项目(863)(No.2013AA031801);上海航天科技创新基金(No.SAST201469);浙江省重大专项项目(No.2014C11SA600010)资助

摘　　要：以仲丁醇铝(ASB)和三甲基乙氧基硅烷(TMEO)为前驱体,采用溶胶-凝胶法,经乙醇超临界干燥制备了耐温高、成型性好的硅/铝复合气凝胶。用透射电子显微镜、N2吸附分析仪、红外光谱仪、X射线衍射仪、hot disk热分析仪等仪器表征了气凝胶的形貌、孔结构、表面基团、晶相、热学等性能。在溶胶-凝胶过程中,通过添加TMEO在氧化铝纳米颗粒表面引入了-Si-(CH_3)_3基团,该基团经高温热处理后会在Al_2O_3表面形成SiO_2纳米颗粒,有效地抑制了Al_2O_3纳米颗粒在高温下的晶体生长,使得该复合气凝胶具有优异的耐温性能。在1 200℃高温处理后,线性收缩低至16%,比表面积可达141 m^2·g^(-1),这将进一步促进气凝胶材料在高温保温隔热、吸附、催化等领域的广泛应用。Silica/alumina composite aerogels with good heat resistance and formability were prepared by a sol-gel method combined with the ethanol supercritical fluid drying technique using aluminum trisec butoxide and trimethylethoxysilane（TMEO） as precursors. Transmission electron microscope, N2 adsorption analyzer, fourier transform infrared spectroscope, X-ray diffraction and hot disk thermal analyzer were used to characterize the morphology, pore structure, surface groups, phases, thermal properties, etc. The-Si-（CH3）3 groups were introduced onto the alumina nanoparticles by adding TMEO during sol-gel process. It is demonstrated that these groups would produce SiO2 nanoparticles, which effectively restricted the crystal growth of Al2O3 nanoparticles and led to the excellent heat resistance of the composite aerogels. The linear shrinkage of the obtained composite aerogel was as low as 16% and the corresponding specific surface area was as high as 141 m2·g-1 after heat treatment at 1200 ℃. This would further contribute to the wide application of aerogels on high-temperature thermal insulation, adsorption, catalysis, etc.

关 键 词：硅/铝复合气凝胶 三甲基乙氧基硅烷 耐高温 高比表面积 

分 类 号：TB333[一般工业技术—材料科学与工程]