仿鸟骨结构纳米纤维复合材料及其在临近空间环境中吸波机制研究

Stealth spacecrafts in near space have important strategic significance in modern national defense. Strong ultraviolet radiation, low temperature, high ozone concentrations require microwave absorbers be good weatherability, low density and excellent mechanical properties. Bird bone has a three-dimensional porous long-range order structure. Inspired by this structure, high performance nanofibers/magnetic nanosheets/conducting polymers will be well fabricated. In this project, the important scientific problem has been well performed based on surface interaction between nanofibers and magnetic nanosheets. The magnetic field or electrical field will be employed to obtain the long range order of magnetic nanosheets. Supercritical drying will be used as powerful tool for bio-inspired bird bone structures. The long range order, the ratio of polymers and magnetic nanosheets, electrical property will be studied in great detail for the general rule designing high performance microwave absorbers in near space.

临近空间隐身飞行器在现代国防中具有重要的战略意义。临近空间环境具有高紫外辐射强度、低温、臭氧浓度高等特点，这就要求隐身吸波材料具有较强的上述耐候性和轻质高强的力学特性。本项目从鸟骨多孔三维有序结构和轻质高强的力学性质受到启发，从解决高性能高分子纳米纤维与无机磁性纳米片界面相容性的基本科学问题出发，以高性能纳米纤维作为磁性纳米片无机分散基质，并通过磁场或电场作用实现无机磁性纳米片的长程有序结构，通过导电高分子原位修饰实现电学性能调控，通过超临界干燥技术实现复合材料的多孔有序结构；揭示纳米纤维复合材料长程有序结构、有机/无机配比、导电性和力学性质在临近空间环境中的电磁吸收规律，建立临近空间环境吸波材料评价体系，最后实现纳米纤维复合材料在临近空间环境超强耐候性、轻质高强力学性能和优异的吸波性能。

临近空间隐身飞行器在现代国防中具有重要的战略意义。临近空间环境具有高紫外辐射强度、低温、臭氧浓度高等特点，要求隐身吸波材料具有较强的上述耐候性和轻质高强的力学特性。本项目从鸟骨多孔三维轻质高强有序结构受到启发，以高性能纳米纤维作为磁性纳米片分散基质，并通过磁场作用实现无机磁性纳米片的长程有序结构；研究纳米纤维复合材料长程有序结构、有机/无机配比在临近空间环境中的电磁波吸收规律。仿鸟骨结构纳米纤维复合膜在厚度为1.5 mm，频率为10.5 GHz时RL达-39 dB；当厚度为2.0 mm时，有效吸收带宽（RL≤-10 dB）达3.2 GHz。此外，在纳米纤维复合膜表面化学气相沉积二氧化硅无机涂层，其阻燃和耐热性能显著提升。极限氧指数为36.5，抗拉强度高至7.5 MPa，柔韧性好。该轻质高强的仿鸟骨结构纳米纤维复合材料在临近空间环境吸波具有潜在的应用价值。