Liu An, Qiu Hua, Lu Xinghan, Guo Hua, Hu Jinwen, Liang Chaobo, He Mukun, Yu Ze, Zhang Yali, Kong Jie, Gu Junwei
Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, P. R. China.
Queen Mary University of London Engineering School, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, P. R. China.
Adv Mater. 2025 Feb;37(5):e2414085. doi: 10.1002/adma.202414085. Epub 2024 Dec 4.
Electromagnetic interference (EMI) shielding materials with low electromagnetic (EM) waves reflection characteristics are ideal materials for blocking EM radiation and pollution. Materials with low reflectivity must be constructed using materials with excellent EM waves absorption properties. However, materials simultaneously possessing both low reflectivity and excellent EMI shielding performance remain scarce, consequently, multilayer structures need to be developed. Poly(p-phenylene-2,6-benzobisoxazole) nanofibers (PNF) are prepared by deprotonation. PNF are combined with MXene and heterostructure MXene@Ni prepared by in-situ growth; MXene@Ni/PNF acts as an EM absorption layer while MXene/PNF acts as an EM reflective layer. Finally, (MXene@Ni/PNF)-(MXene/PNF) aerogels are prepared by layer-by-layer freeze-drying based on the layered modular design concept. Experimental characterizations revealed that (MXene@Ni/PNF)-(MXene/PNF) aerogels enable the efficient absorption-reflection-reabsorption of EM waves, effectively eliminating EMI. When the mass ratio of MXene to Ni in MXene@Ni is 1:6 and the mass fraction of MXene in the reflective layer is 80 wt.%, the (MXene@Ni/PNF)-(MXene/PNF) aerogels exhibit excellent EMI shielding performance (71 dB) and a very low reflection coefficient (R = 0.10). Finite element simulations verified that the developed asymmetric structural aerogels achieve high EMI shielding performance with low reflection characteristics. In addition, (MXene@Ni/PNF)-(MXene/PNF) aerogels display excellent infrared camouflage ability.
具有低电磁波反射特性的电磁干扰（EMI）屏蔽材料是阻挡电磁辐射和污染的理想材料。低反射率的材料必须使用具有优异电磁波吸收性能的材料来构建。然而，同时具备低反射率和优异EMI屏蔽性能的材料仍然稀缺，因此，需要开发多层结构。聚（对亚苯基-2,6-苯并双恶唑）纳米纤维（PNF）通过去质子化制备。PNF与通过原位生长制备的MXene和异质结构MXene@Ni相结合；MXene@Ni/PNF用作电磁吸收层，而MXene/PNF用作电磁反射层。最后，基于分层模块化设计理念，通过逐层冷冻干燥制备了（MXene@Ni/PNF）-（MXene/PNF）气凝胶。实验表征表明，（MXene@Ni/PNF）-（MXene/PNF）气凝胶能够实现电磁波的高效吸收-反射-再吸收，有效消除电磁干扰。当MXene@Ni中MXene与Ni的质量比为1:6且反射层中MXene的质量分数为80 wt.%时，（MXene@Ni/PNF）-（MXene/PNF）气凝胶表现出优异的EMI屏蔽性能（71 dB）和非常低的反射系数（R = 0.10）。有限元模拟验证了所开发的不对称结构气凝胶在低反射特性下实现了高EMI屏蔽性能。此外，（MXene@Ni/PNF）-（MXene/PNF）气凝胶具有优异的红外伪装能力。
