Multifunctional SiC aerogel reinforced with nanofibers and nanowires for high-efficiency electromagnetic wave absorption

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2023-07, Vol.467, p.143518, Article 143518
• Main Authors: Song, Limeng, Wu, Chengwen, Zhi, Qing, Zhang, Fan, Song, Bozhen, Guan, Li, Chen, Yongqiang, Wang, Hailong, Zhang, Rui, Fan, Bingbing
• Format: Article
• Language: English
• Subjects: Ceramic aerogels; Freeze casting; High efficiency EMW absorption; Monolithic; Multifunctional
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.143518

[Display omitted] •SiC aerogels were prepared by freeze casting, carbonation and calcination process.•SiC aerogels were composed of SiC nanofibers, nanowires, and nanosheets.•SiC aerogel-2 shows a RLmin of −61.56 dB and an EABmax of 9.82 GHz. Ceramic aerogels with recoverable compressibility, super-insulation capacity, and remarkable thermal and chemical stability are fascinating for use in the field of high-level electromagnetic wave (EMW) absorption. However, integrating multiple functions into a monolithic ceramic aerogel using presently available fabrication techniques remains a challenge. Therefore, we employed a novel strategy to successfully synthesize a multifunctional and monolithic SiC ceramic aerogel using a simple freeze casting technique with a subsequent carbonation and calcination process. The as-synthesized SiC aerogel-2 exhibits ultralow density, fire resistance, high-temperature chemical and thermal stability, and excellent insulating properties. Notably, the one-dimensional SiC nanofibers and nanowires inside the SiC aerogel-2 act as a reinforcement to ensure the presence of a stable porous structure. The sample exhibits excellent mechanical performance and also achieves ideal impedance matching to present high-efficiency EMW-absorbing properties, including a minimum reflection loss (RLmin) of − 61.56 dB and a maximum effective absorption bandwidth (EABmax) of 9.82 GHz. Thus, the successful fabrication of multifunctional SiC aerogels will pave the way for the development and widespread application of high-level EMW absorption materials in aviation and aerospace fields.