Hierarchal 3D porous carbon materials show huge potential for EMI shielding because of their adjustable pore structure, tunable morphology and high electrical conductivity. However, poor graphitic nature and improper contact between materials lead to reduce the inherent conductivity, which supress the EMI shielding performance. In this work, we designed a hierarchical Carbon–Carbon nanostructure, which resembles a ‘sea-urchin’, exhibiting high shielding performance. A facile strategy of microwave assisted growth of carbon nanofiber (CNF) on the ‘self-assembled’ carbon urchin (CU) holds the rank of hierarchy, which enhance the electrical contact between the urchins. In order to obtain a 3D construct, a classical Ionomers pair-PEDOT:PSS was chosen as the matrix and CNF@CU was infused and subjected to freeze-drying to design ultra-light aerogel. The morphological assessment reveals that CNF@CU in the aerogel offers trapping centers by providing multiple interfaces. The aerogels exhibited two orders of jump in electrical conductivity and showed excellent thermal stability. The high limiting oxygen index value begins to suggest that these aerogels can extend their utility to flame retardant materials. The EMI shielding properties of the construct were studied in the X-band (8.2–12.4 GHz). The aerogel with 1.7 wt% of CNF@CU exhibited −50.8 dB of shielding efficiency (representing 99.999% blocking). The excellent EMI performance achieved here is mainly due to the conductive losses, dipole polarization, interface polarization, and wave trappers. These wave trappers are extremely beneficial for shielding EM radiations through multiple scattering. The utility of these materials were further evaluated using a Bluetooth module, wherein the aerogel potentially blocked all the transmitting Bluetooth signals confirming the quick shielding quality of the proposed aerogel. Taken together, this work provides a facile approach for designing and developing lightweight aerogel based EMI shielding materials.

分层 3D 多孔碳材料显示出巨大的 EMI 屏蔽潜力，因为它们具有可调节的孔结构、可调的形态和高导电性。然而，不良的石墨性质和材料之间的不当接触导致固有导电率降低，从而抑制了EMI屏蔽性能。在这项工作中，我们设计了一种类似于“海胆”的分层碳-碳纳米结构，具有高屏蔽性能。一种简便的微波辅助生长碳纳米纤维 (CNF) 在“自组装”碳海胆 (CU) 上的策略具有层次结构，可增强海胆之间的电接触。为了获得 3D 结构，选择经典的离聚物对-PEDOT:PSS 作为基质，注入 CNF@CU 并进行冷冻干燥以设计超轻气凝胶。形态学评估表明，气凝胶中的 CNF@CU 通过提供多个界面来提供捕获中心。气凝胶在电导率方面表现出两个数量级的跳跃，并表现出出色的热稳定性。高极限氧指数值开始表明这些气凝胶可以将其用途扩展到阻燃材料。该构造的 EMI 屏蔽特性在 X 波段 (8.2–12.4 GHz) 中进行了研究。含有 1.7 wt% CNF@CU 的气凝胶表现出 -50.8 dB 的屏蔽效率（代表 99.999% 的阻挡）。此处实现的出色 EMI 性能主要归功于传导损耗、偶极极化、界面极化和陷波器。这些波捕获器非常有利于通过多次散射屏蔽 EM 辐射。使用蓝牙模块进一步评估了这些材料的实用性，其中气凝胶可能会阻挡所有传输的蓝牙信号，从而证实了所提出的气凝胶的快速屏蔽质量。总之，这项工作为设计和开发基于轻质气凝胶的 EMI 屏蔽材料提供了一种简便的方法。