碳化硅块状气凝胶的制备及应用

Preparation and Applications of Silicon Carbide Monolithic Aerogels

碳化硅气凝胶具有高温稳定性、低热膨胀系数、良好的抗热震性以及抗氧化和耐腐蚀等优异的性质,在高温和高腐蚀性环境下的隔热、电磁吸波、过滤和吸附等领域具有较大的应用潜力。然而,块状碳化硅气凝胶的可控制备一直是一项较大的挑战。本文综述了块状碳化硅气凝胶在制备工艺和应用两个方面的研究进展,首先分析总结了各种制备工艺及其优缺点,包括有机/SiO_(2)复合气凝胶碳热还原法、预陶瓷化聚合物裂解法、化学气相沉积法、高温气相渗硅法和碳化硅纳米线组装法;然后,详细介绍了碳化硅气凝胶在高温隔热和电磁吸波两个领域的应用研究进展;最后,展望了碳化硅气凝胶未来的若干发展方向。

Silicon carbide aerogels have excellent properties such as high temperature stability,low thermal expansion coefficient,good thermal shock resistance,oxidation resistance and corrosion resistance,etc.They have great application potential in the fields of high temperature thermal insulation,electromagnetic wave adsorbing,filtration and adsorption under high temperature and high corrosive environment.However,the controllable preparation of bulk silicon carbide aerogels has always been a major challenge.As a new kind of aerogels,the preparation process of bulk SiC aerogels is more complicated than that of traditional oxide and carbon aerogels.In recent years,the research on preparation and application of SiC aerogels has entered a new stage.Many new strategies for preparing SiC aerogels have been developed,and many important progress has been made in the research of SiC aerogels in the fields of heat insulation and electromagnetic wave adsorbing.In this paper,the research progress on preparation and application of monolithic silicon carbide aerogels is reviewed.Firstly,the advantages and disadvantages of various preparation technologies are analyzed and summarized,including carbon thermal reduction method with organic/SiO_(2) composite aerogels,cracking method with pre⁃ceramic polymer,chemical vapor deposition method,high⁃temperature vapor⁃phase silicon cementation method and self⁃assembly method of SiC nanowire.Then the application research progress of SiC aerogel in high temperature insulation and electromagnetic wave adsorbing are introduced in detail.Finally,the development trend of SiC aerogel in the future is prospected.