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›› 2002, Vol. 2 ›› Issue (4): 0-0.

• 4 •    

纳米孔超级绝热材料气凝胶的制备与热学特性

沈军，周斌，吴广明，邓忠生，倪星元，王珏   

  1. 同济大学波耳固体物理研究所，上海 200092
  • 出版日期:2002-08-20 发布日期:2002-08-20

Preparation and Investigation of Nanoporous Super Thermal Insulation: Silica Aerogels

SHEN Jun, ZHOU Bin, WU Guang-ming, DENG Zhong-sheng, NI Xing-yuan, WANG Jue   

  1. Institute of Process Engineering, CAS, Beijing 100080, China
  • Online:2002-08-20 Published:2002-08-20

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摘要： 以正硅酸四乙酯(TEOS)为硅源，通过溶胶–凝胶及超临界干燥过程制备了SiO2气凝胶. 同时，采用相对廉价的多聚硅(E–40)为硅源，以三甲基氯硅烷(TMCS)为表面修饰剂，硅油为干燥介质, 在常压条件下制备了同样具有纳米多孔结构的SiO2气凝胶. 用透射电镜、扫描电镜及孔径分布仪对其结构进行了表征，并用动态热线法对其热学特性进行了测试. 结果表明: 两种方法制备的气凝胶均是典型的纳米孔超级绝热材料，后者热导率略高但成本低许多，所以更具应用推广潜力.

关键词: SiO2气凝胶, 纳米孔, 溶胶–凝胶, 热导率

Abstract: Al2O3-coated nano-ZnO composite powder was obtained by coating precursor in slurry of basic zinc carbonate. The composite powder was examined by UV-VIS and TEM, and its photocatalytic activity was determined by photooxidation of castor oil illuminated under a high pressure mercury lamp. The composite particles are about 50 nm, and coated homogeneous film is 3~5 nm thick. The composite powder has nice ultraviolet- adsorption as good as un-coated nano-ZnO and its photocatalytic activity is reduced significantly. Compared with coating the calcined product ZnO powder surface, less steps are required in this coating process. As a result, the agglomeration during preparation steps is avoided.

Key words: SiO2 aerogel, nanoporous, sol–gel, thermal conductivity

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