The academician team of Yu Shuhong, China University of Science and Technology, developed a new type of spacecraft outer protective material – polyimide-nano-macular composite film. This new material has been significantly improved due to its unique bionic design, and its mechanical properties and extreme environmental tolerance are significantly improved, which is expected to replace existing polyimide-based composite film materials. This results have been published in "Advanced Materials".
The polyimide film is a perfect material of the space detector "protective clothing" due to its excellent mechanical properties, excellent thermal stability and protruding chemical resistance. However, like other hydrocarbon polymers, the material is extremely susceptible to atomic oxygen attack in the space environment, causing its physical and mechanical properties to drop sharply, and there is currently no good solution. In addition, cosmic radiation and space debris impact also bring severe tests to their stability.
Yu Shuhong team is inspired by natural pearl mother’s "brick-mud" layered structure, using the pre-mechanical properties and ultraviolet mask function and can be prepared as a structural element, with polyimide precursor The polyimide-nanocomposite film is co-assembled, and the superior intrinsic characteristics of mica make up for the lack of polyimide. Different from the conventionally imitation pearl layer nanocomposite film, researchers have double-layer pearl layer structures by changing group distribution ratios, with a two-layer pearl layer structure, with a more dense nammother piece. This design strategy not only achieves effective improvement in material mechanical properties, but also facing atomic oxygen, ultraviolet radiation and spatial debris or the like.
Studies have shown that the tensile strength, Young’s modulus and surface hardness of this novel bionic composite film are 125 MPa, 2.2 Gpa and 0.37 GPpa, 45%, 100%, respectively, 100%, respectively, 100%, respectively, 100%, respectively, 100%, respectively, 100% And 68%, its performance is significantly better than the polyimide-mica composite film of the pure polyimide film, a single layer of pearl mother structure, and a polyimide-based composite containing conventional reports. In addition, its anti-ultraviolet aging and high temperature stability are also significantly improved.
The industry believes that this research proposed unique double imitation pearl mother structure design strategy, providing new ideas for designing other high-performance nanocomposites. (Guiyun An)