Recently, the results of a new type of aramid ceramic aerogel nanocomposite by the research team of the University of Buffalo were published in the journal Advanced Engineering Materials. This material has the characteristics of maintaining high mechanical wear resistance from low to high temperature. Make it a promising candidate for low-cost manufacturing of wearable textiles for applications in harsh environments, including aerospace, electronics and personal protective clothing.
Aramid is more widely known as a protective fiber application under the Kevlar® trademark (Kevlar) as a functional and structural material. The powder circle has reported that Russia plans to replace steel armor with ceramic + fabric for heavy guided missile destroyers in 2023. The reason is that aramid is light and has good protection, but the cost is high; composite ceramics can enhance protection and reduce costs. Combining the performance of two artificial materials, aramid and ceramic, can reduce the weight while improving the protective effect, which has greatly improved the survivability of the ship.
However, the above reported application is the application of structural design and assembly of two materials. This research is to combine the two materials organically, which undoubtedly gives better play to the advantages of materials and expands the application space. The material parameters show that its characteristics are: low density (0.08g cm-3), low thermal conductivity (0.034W m-1 K-1) and high compressibility. The mechanical strength of the ceramic aerogel nanocomposite is 1.1MPa.
The research team introduced the preparation method. "Industrialized production strategy is used as a guide to prepare composite fibers through in-situ cross-linking of nanoporous silica aerogel and aramid fibers. The synthesized nano composite fibers form a three-dimensional network and hollow mesoporous silica. The aerogel matrix is connected, and the aerogel fiber structure has interconnected porous networks and high still air layer content. Even in the extreme environment of -196°C to 400°C, the aramid fiber aerogel composite material is also It has extraordinary thermal insulation properties."
The key to this method is the in-situ cross-linking between the silica pre-ceramic aerogel precursor and the aramid fiber. In the atmospheric drying reaction, the precursor is transformed into nanoporous SiO2 aerogel and deposited on the aramid fiber. Aramid fibers form a percolation network, while aerogels are cross-linked and deposited on the fiber network. The interface combination of aramid fiber and aerogel after gelation further prevents the collapse of the fiber network.
The researchers pointed out that this material is also suitable for 3D printing. The team is studying specific applications, including thermal insulation and wear-resistant systems, impact-resistant armor applications, and structural components in thermal applications.