Wear-resistant and heat-insulating materials used in harsh environments will more or less encounter unexpected conditions encountered in the design and manufacturing process. On the one hand, the product needs to maintain its characteristics to provide impact resistance, but under high temperature conditions, performance degradation often occurs, that is, the heat resistance deteriorates. In many cases, this requires the use of several materials to make fabrics, and the manufacturing process of such strong and durable thermal protection textiles will be more complicated.
Aramid fiber is widely used in protective applications as a functional and structural material. Aramid fiber has excellent mechanical properties and is widely used as a functional and structural material in protective applications, such as protective clothing for firefighters and emergency personnel. Although resistant to high temperatures, the thermal properties of aramid fibers limit their applications. Due to their relatively high thermal conductivity and temperature-sensitive polymer properties, aramid fibers cannot be provided in various temperature ranges from low to high temperatures. Adequate thermal protection while maintaining its strong mechanical properties.
In contrast, ceramic aerogels have super-insulating properties due to their high specific surface area and low-density mesoporous structure. However, these ultra-light materials have the problems of mechanical brittleness and poor mechanical properties.
Researchers at the University of Buffalo have combined the advantages of these two fields to develop a wear-resistant aramid/ceramic aerogel nanocomposite with excellent mechanical and thermal properties.
A sample of a new type of aramid aerogel nanocomposite material is placed on the flower bud, demonstrating the lightweight properties of this material. These properties make this new nanocomposite material a promising candidate for low-cost manufacturing of wearable textiles for applications in harsh environments, including aerospace, electronics and personal protective clothing.
A team led by a professor at the University of Buffalo reported their findings in advanced engineering materials aramid ceramic aerogel composites, showing a low density (0.08 g cm-3), low thermal conductivity (0.034 W m- 1 K-1) and the mechanical strength of the highly compressible ceramic aerogel nanocomposite is 1.1 MPa. A process plan for preparing aramid aerogel fabric by in-situ cross-linking reaction of pre-aerogel precursors (HCl, CTAB micelles, urea and sodium silicate) with aramid fibers. The researchers explained the manufacturing process: “We adopted a simple and scalable manufacturing strategy to prepare nanocomposites through in-situ cross-linking reactions between nanoporous silica aerogels and aramid fibers. The synthesized nanocomposite fibers A 3D network is formed, connected to the hollow mesoporous silica matrix.". "The aerogel fiber structure has an interconnected porous network and a high still air layer content. Even in the extreme environment of -196°C to 400°C, the aramid fiber aerogel composite material has extraordinary heat insulation.
The key to this preparation method is the in-situ cross-linking between the silica and the ceramic aerogel precursor and the aramid fiber. In the atmospheric drying reaction, the precursor is converted into nanoporous silica aerogel and deposited on the aramid fiber. Aramid fibers form a percolation network, while silica gel is 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.
After successfully demonstrating the excellent performance of nanocomposite insulating materials, the team is studying specific applications, including thermal insulation and wear-resistant systems, impact-resistant armor applications, and structural components in heat-sensitive applications.