Opacifier embedded and fiber reinforced alumina-based aerogel composites for ultra-high temperature thermal insulation |
| |
| Affiliation: | 1. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China;2. Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy, North China Electric Power University, Beijing 102206, China;3. Key Laboratory for Thermal Science and Power Engineering of MOE, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China;4. National Key Laboratory of Advanced Functional Composite Materials, Aerospace Research Institute of Materials and Processing Technology, Beijing 100076, China;1. School of Civil Engineering, Guangzhou University, Guangzhou 510006, China;2. Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong, China |
| |
| Abstract: | A novel method was developed to uniformly disperse sub-micron TiO2 opacifier into fiber reinforcements using agar and silica as binders via freeze drying. TiO2 opacifier/ fiber/ alumina-based aerogel ternary (TFA) composites with high strength and excellent high-temperature thermal insulation were successfully prepared by sol-gel route, impregnation process and supercritical fluid drying. The microstructure, mechanical and thermal insulation properties of TFA composites were investigated comprehensively. The results show that the mechanical property of TFA composites can be significantly enhanced by mullite fiber felt and the incorporation of SiO2 binder. The effect of TiO2 opacifier on the high-temperature thermal conductivity was studied by adjusting the content of TiO2 from 0 to 15 wt%. The obtained TFA composites exhibit high Young's modulus of up to 3.58 MPa and low high-temperature thermal conductivities of 0.129 W/m·K at 800 °C and 0.168 W/m·K at 1000 °C, respectively. The mechanism of heat transfer in TFA composites at high-temperature was also analyzed. |
| |
| Keywords: | Alumina-based aerogel Thermal conductivity High-temperature thermal insulation |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
