材料科学
气凝胶
复合材料
热导率
复合数
保温
热稳定性
抗压强度
纳米线
多孔性
微观结构
化学工程
纳米技术
图层(电子)
工程类
作者
Lipeng Wang,Wenxian Lian,Bo Yin,Xingping Liu,Shaokun Tang
标识
DOI:10.1016/j.ceramint.2023.12.008
摘要
Silica aerogels possess extremely low thermal conductivity, low density and high porosity, which can be regarded as candidates for new thermal insulation materials. However, silica aerogels suffer from low strength, brittleness, modeling difficulties and high moisture absorption. In this work, compatible inorganic silica nanowires are introduced as one-dimensional reinforcing materials, and silica nanowires-reinforced silica aerogels (SiO2NWs-MSAs) are synthesized using a two-step acid-base catalytic in-situ sol-gel method combined with atmospheric pressure drying, aiming to improve the comprehensive performances of the composite aerogels. The composite aerogels exhibit good mechanical properties, and the composite aerogel has a compressive strength of 1.379 MPa at a strain of 60 % when the doping amount of silica nanowires is 11 %. The volumetric shrinkage of the composite aerogels varies between 11.58 and 12.81 % and the density ranges from 0.11 to 0.13 g cm−3. SiO2NWs-MSA2 has a low thermal conductivity and good high-temperature insulation properties with thermal conductivity of 0.039 W m−1 K−1 at 25 °C and 0.046 W m−1 K−1 at 150 °C. The thermal stability of the composite aerogels is improved, and the thermal decomposition temperature reaches 500 °C. Meanwhile, the water contact angles of the composite aerogels all exceed 140°. In addition, the composite aerogels can maintain the amorphous state at 1200 °C, and the microstructure remains basically unchanged at 1000 °C, showing excellent high-temperature resistance.
科研通智能强力驱动
Strongly Powered by AbleSci AI