A research team from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed advanced aerogel composites that integrate high-temperature insulation with mechanical load-bearing capabilities, while also achieving controllable fabrication of large-size samples.
The findings were published in Materials Today Energy and Journal of Materials Research and Technology.
As high-performance systems are increasingly deployed in extreme conditions, there is a growing need for insulation materials that are not only lightweight and thermally efficient but also mechanically strong and stable at elevated temperatures. Traditional aerogels, known for their ultra-low density and excellent insulating properties, often suffer from poor mechanical integrity, limited thermal stability, and challenges in large-scale manufacturing-hindering their practical application in demanding environments.
To address these challenges, the researchers built upon their previous work and developed a carbon fiber reinforcement strategy to create high-performance aerogel composites. By introducing expandable graphite as an interfacial bonding agent, they constructed a robust multi-scale framework that significantly enhanced structural integrity and resistance to thermal deformation. The resulting composites maintained mechanical strength under load while providing efficient thermal insulation across a wide temperature range.
In parallel, for ceramic-based aerogel composites, the researchers proposed a novel precursor impregnation and in-situ dual-morphology growth technique. This approach enabled the simultaneous formation of dense silicon carbide coatings and a network of nanowires within the carbon fiber structure, greatly improving oxidation resistance and ablation performance. Even after exposure to extremely high temperatures, the composites retained their lightweight structure, mechanical strength, and excellent thermal insulation properties, demonstrating strong potential for future thermal protection applications.
Importantly, both types of composites demonstrated the feasibility of large-size fabrication, with samples successfully prepared and capable of being cut and processed as needed.
These progresses provide new technical pathways for the engineering applications of aerogel composites.
The synthesis schematic (a), microstructure characterization (b-e), thermal conductivities at different temperatures (f), stress-strain curves (g) and molding performance (h) of the carbon-based aerogel composites. (Image by YU Jie)
