Researchers have developed an ultralight, anisotropic silicon carbide (SiC) aerogel using cornstalk biomass as a carbon source. Produced through a carbonisation–thermal reduction process, the aerogel has a density of less than 41.8 mg/cm³ and an oriented porous structure that can respond more effectively to environmental conditions. The team published their study in the KeAI journal Defence Technology .
"Conventional biomass-derived carbon aerogel absorbers cannot meet the service requirements of high-temperature aerospace scenarios, which are plagued by severe oxidation failure under hot-oxygen environments," explains corresponding author Professor Bingbing Fan. “To overcome this material bottleneck, we selected natural corn-stalk pith with intrinsic aligned honeycomb channels as biotemplate and explored anisotropic SiC aerogel prepared via carbonization and catalyst-free carbothermal reduction.”
The researchers produced three distinct directional specimens: parallel-growth, 45 o -diagonal and perpendicular-growth SiC aerogel, each showing vastly different electromagnetic-wave absorption and thermal insulation performances. “Though all samples possess lightweight porous features, only the perpendicular-growth sample delivers outstanding comprehensive properties,” says Fan. “The parallel-growth counterpart exhibits relatively weak absorption capacity and inferior heat-shielding effect, which cannot satisfy practical protection demands.”
The team then implemented a series of material characterizations including SEM, TEM and vector network analyzer tests to clarify structure‑property correlation, while adopting RCS simulation to assess real-world stealth potential. “Abundant grain boundaries, stacking faults and heterogeneous interfaces inside SiC aerogel serve as charge-accumulation sites and produce strong interfacial polarization,” shares Fan. “The inherited honeycomb pore architecture reshapes heat conduction and electromagnetic‑wave propagation paths for different orientations.”
Experimental results demonstrated that biomass‑induced anisotropy dominates the multifunctional performance of SiC aerogel. "This study uncovers the structure‑function coupling mechanism of biomass-originated anisotropic SiC aerogel," adds Fan. "It provides a feasible green preparation strategy for developing integrated materials combining electromagnetic absorption and high-temperature thermal insulation."
###
Contact the author: Bingbing Fan, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China. fanbingbing@zzu.edu.cn
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Defence Technology
Experimental study
Not applicable
Biomass‑derived anisotropic silicon carbide aerogels with orientation‑dependent electromagnetic absorption and high‑temperature insulation performance
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.