Qiao Shiya, Chen Haiming, Zhao Yuehao, Wang Zhen, Yan Jingling
Laboratory of Polymers and Composites, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China.
Ningbo Key Laboratory of High-Performance Polymers and Composites, Ningbo, 315201, China.
Adv Mater. 2025 Aug 19:e13423. doi: 10.1002/adma.202513423.
Lightweight polymer-based electromagnetic interference (EMI) shielding materials exhibiting good mechanical adaptability and thermal stability are pivotal for next-generation electronics. However, conventional approaches utilized to enhance the EMI shielding efficiency (SE) through porous architectures often compromise the structural integrity of the material or its EMI shielding performance under dynamic deformation. Herein, a morphogenetic approach is proposed to precisely coordinate the precursor thermodynamics by tuning the carbon nanotube (CNT) content and precursor concentration in the framework of the freeze-drying method. With this method, polyimide/CNT aerogels with unprecedented triaxial hierarchical architectures (macroscopic core-radiating patterns, microscopic omasum-like folds, and nanoscopic CNT bridges) are obtained. The synergy between these multiscale structures extends the dissipation pathways of electromagnetic waves by inducing multiple reflections, yielding an EMI SE of 71 dB and an ultrahigh specific efficiency (6470 dB cm g). Remarkably, the C67-5.0 aerogels also exhibit enhanced EMI shielding performance with temperature (5.0% improvement at 350 °C), a negative Poisson's ratio (around -0.28), and structural stability (≈90% height retention after 500 compression cycles). This unique combination of a high EMI SE, outstanding mechanical properties, and excellent structural compressibility opens new avenues for designing adaptive EMI shielding systems for application to aerospace and electronics industries.
具有良好机械适应性和热稳定性的轻质聚合物基电磁干扰(EMI)屏蔽材料对下一代电子产品至关重要。然而,通过多孔结构提高EMI屏蔽效率(SE)的传统方法往往会损害材料的结构完整性或其在动态变形下的EMI屏蔽性能。在此,提出了一种形态发生方法,通过在冷冻干燥方法的框架内调节碳纳米管(CNT)含量和前驱体浓度来精确协调前驱体的热力学。通过这种方法,获得了具有前所未有的三轴分级结构(宏观核心辐射图案、微观瘤胃样褶皱和纳米级CNT桥)的聚酰亚胺/CNT气凝胶。这些多尺度结构之间的协同作用通过诱导多次反射扩展了电磁波的耗散路径,产生了71 dB的EMI SE和超高的比效率(6470 dB cm g)。值得注意的是,C67-5.0气凝胶还表现出随温度增强的EMI屏蔽性能(在350°C时提高5.0%)、负泊松比(约-0.28)和结构稳定性(500次压缩循环后高度保留率约为90%)。这种高EMI SE、出色的机械性能和优异的结构可压缩性的独特组合为设计适用于航空航天和电子行业的自适应EMI屏蔽系统开辟了新途径。