摘要
通过纳米晶组装技术,构筑了Al2O3-SiO2复合气凝胶;利用不同组分耐温性的差异,经过热处理过程得到了骨架强健的Al2O3-SiO2气凝胶.研究了不同配比及热处理温度对材料微观结构和组分的影响,确定了最佳制备条件,得到了比表面积为123. 9 m^2/g,密度为0. 25 g/cm^3,导热系数为0. 029 W·m^-1·K^-1的气凝胶材料.在泡水和冰冻等极端环境下,气凝胶材料未发生结构的破坏,模拟10次重复隔热应用(800℃,30 min)后导热系数保持不变.该隔热性气凝胶的开发有望解决未来飞行器隔热材料需重复使用的技术瓶颈,为开发新型气凝胶隔热材料提供了新思路.
An Al2O3-SiO2 composite aerogel with robust mechanical property was constructed by nanocrystalline assembly. Due to different heat resistance of Al2O3 and SiO2,robust Al2O3-SiO2 aerogel can be prepared by controlling treating temperature. The effects of Al/Si molar ratio and treating temperature on microstructure were studied and the best experiment condition was obtained. The aerogel gets densities of 0. 25 g/cm^3,specific surface of 123. 9 m^2/g,thermal coefficient of 0. 029 W·m^-1·K^-1 fabricated in the best experiment condition. The test result showed that the microstructures of aerogel unchanged in extreme conditions such as water immersion and freeze. And thermal coefficient of aerogel still remains 0. 029 W · m^-1·K^-1 after 10 cycles heat treatment( 800 ℃,30 min). The robust Al2O3-SiO2 aerogel is expected to solve the problem that thermal insulation material cannot be used repeatedly in future aerospace vehicles and near space vehicles.This method prove a new idea for new aerogel insulation materials.
作者
张恩爽
黄红岩
刘韬
贺丽娟
郭慧
李文静
张凡
杨洁颖
张昊
赵英民
ZHANG Enshuang;HUANG Hongyan;LIU Tao;HE Lijuan;GUO Hui;LI Wenjing;ZHANG Fan;YANG Jieying;ZHANG Hao;ZHAO Yingmin(Aerospace Institute of Advanced Material&Processing Technology,Beijing 100074,China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第12期2566-2573,共8页
Chemical Journal of Chinese Universities
关键词
空天飞行器
纳米孔
气凝胶
可重复使用性能
隔热材料
Aerospace vehicle
Nanopores
Aerogel
Reusable property
Thermal insulation material
作者简介
联系人:李文静,女,博士,研究员,主要从事热防护材料研究.E-mail:ht3lwj@126.com。
