Nanotechnology Now - Press Release: Researchers develop polyimide-mica nanocomposite film with high resistance to low earth orbit environments

In a study published in Advanced Materials, a research team led by Prof. YU Shuhong from University of Science and Technology of China (USTC) of the Chinese Academy of Sciences proposed a unique double-layer nacre-inspired structural design strategy, and fabricated a new PI-based nanocomposite film with greatly enhanced mechanical properties and AO resistance.

Inspired by the brick-and-mortar microstructure of natural nacre, researchers assembled mica nanosheets and PI into a double-layer nacre-inspired structure with a much higher density of mica in the top layer, which was achieved via a straightforward spray assisted assembly followed by a thermo-curing process.

By optimizing the component proportions and top layer thickness, the mechanical properties of the double-layer PI-Mica film were significantly enhanced. The tensile strength, Young�s modulus, and surface hardness of the double-layer film were 45%, 100%, and 68% higher than those of pure PI films, respectively.

By virtue of the unique double-layer nacre-inspired structure and the intrinsic advantages of mica nanosheets, the obtained double-layer PI-Mica film achieved much better AO resistance, UV aging resistance (313 nm), and high-temperature stability (380 ℃) than pure PI film. In addition, both AO fluence and erosion yield characteristics of the double-layer PI-Mica film are superior to previously reported PI-based composites. Thus, this double-layer PI-Mica film may serve as a new type of aerospace protective material, replacing existing PI-based composite films for LEO applications.

The unique double-layer nacre-inspired structural design provides a promising avenue for future design and fabrication of other high-performance bioinspired nanocomposites for diverse applications.