Guo Zhengzheng, Ren Penggang, Yang Fan, Wu Tong, Zhang Lingxiao, Chen Zhengyan, Huang Shengqin, Ren Fang
School of Materials Science and Engineering, Xi'an University of Technology, Xi'an710048, China.
The Faculty of Printing, Packaging Engineering and Digital Media Technology, Xi'an University of Technology, Xi'an710048, China.
ACS Appl Mater Interfaces. 2023 Feb 8;15(5):7308-7318. doi: 10.1021/acsami.2c22447. Epub 2023 Jan 24.
Exploring electromagnetic interference (EMI) shielding materials with ultra-efficient EMI shielding effectiveness (SE) and an absorption-dominated mechanism is urgently required for fundamentally tackling EMI radiation pollution. Herein, zeolitic imidazolate framework-67 (ZIF-67)/MXene/cellulose aerogels were first prepared via a simple solution mixing-regeneration and freeze-drying process. Subsequently, they are converted into electric/magnetic hybrid carbon aerogels (Co/C/MXene/cellulose-derived carbon aerogels) through a facile pyrolysis strategy. ZIF-67-derived porous Co/C could provide the additional magnetic loss capacity. The resultant electric/magnetic hybrid carbon aerogels exhibit a hierarchically porous structure, complementary electromagnetic waves (EMWs) loss mechanisms, and abundant heterointerfaces. The construction of a porous architecture and the synergy of electric/magnetic loss could greatly alleviate the impedance mismatching at the air-specimen interface, which enables more EMWs to enter into the materials for consumption. Moreover, numerous heterointerfaces among Co/C, TiCT MXene, and cellulose-derived carbon skeleton induce the generation of multiple polarization losses containing interfacial and dipole polarization, which further dissipate the EMWs. The resultant electric/magnetic hybrid carbon aerogel with a low density (85.6 mg/cm) achieves an ultrahigh EMI SE of 86.7 dB and a superior absorption coefficient of 0.72 simultaneously. This work not only offers a novel approach to design high-performance EMI shielding materials entailing low reflection characteristic but also broadens the applicability of electric/magnetic hybrid carbon aerogels in aerospace, precision electronic devices, and military stealth instruments.
迫切需要探索具有超高效电磁干扰(EMI)屏蔽效能(SE)和以吸收为主导机制的EMI屏蔽材料,以从根本上解决EMI辐射污染问题。在此,首次通过简单的溶液混合-再生和冷冻干燥工艺制备了沸石咪唑酯骨架-67(ZIF-67)/MXene/纤维素气凝胶。随后,通过简便的热解策略将它们转化为电/磁混合碳气凝胶(Co/C/MXene/纤维素衍生碳气凝胶)。ZIF-67衍生的多孔Co/C可以提供额外的磁损耗能力。所得的电/磁混合碳气凝胶具有分级多孔结构、互补的电磁波(EMW)损耗机制和丰富的异质界面。多孔结构的构建以及电/磁损耗的协同作用可以极大地缓解空气-样品界面处的阻抗失配,使更多的EMW能够进入材料中被消耗。此外,Co/C、TiCT MXene和纤维素衍生碳骨架之间的大量异质界面诱导产生了包含界面极化和偶极极化的多种极化损耗,进一步耗散了EMW。所得的低密度(85.6 mg/cm)电/磁混合碳气凝胶同时实现了86.7 dB的超高EMI SE和0.72的优异吸收系数。这项工作不仅提供了一种设计具有低反射特性的高性能EMI屏蔽材料的新方法,还拓宽了电/磁混合碳气凝胶在航空航天、精密电子设备和军事隐身仪器中的应用范围。