Abstract Flexible, low-density, high-performance electromagnetic interference (EMI) shielding performance materials are urgently required in aerospace and flexible electronic devices. Due to the high aspect ratio and conductivity, carbon nanotube (CNTs) has been considered as one of the most promising candidates for providing excellent EMI shielding performance. Here, a flexible spongy CNTs consisting of self-assembled, interconnected CNT skeletons, with a density of 10.0 mg/cm3, was directly used as EMI shielding film. The freestanding CNT sponge with a thickness of 1.8 mm shows highly EMI shielding effectiveness (SE) and specific SE (SSE) of 54.8 dB and 5480 dB cm3/g in X-band, respectively. The performance of the CNT sponges can be further improved by increasing the thickness or density of the samples. After composited with PDMS by directly infiltrating method, the CNT/PDMS film still exhibits excellent EMI SE (46.3 dB) at the thickness of 2.0 mm, while the CNT loading content is less than 1.0 wt%. The EMI SE of the composite is almost unchanged after repeated stretching or bending for 1000 cycles. The flexible, stability, and highly conductive nanocompsite can be directly used as high-performance EMI shielding films in areas such as packaging, electronics and communication.

中文翻译：

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用于高性能电磁干扰屏蔽的柔性轻质碳纳米管海绵和复合材料

摘要 航空航天和柔性电子设备迫切需要柔性、低密度、高性能的电磁干扰（EMI）屏蔽性能材料。由于高纵横比和导电性，碳纳米管 (CNT) 被认为是提供出色 EMI 屏蔽性能的最有希望的候选者之一。在这里，由自组装、互连的 CNT 骨架组成的柔性海绵状碳纳米管，密度为 10.0 mg/cm3，直接用作 EMI 屏蔽膜。厚度为 1.8 mm 的独立式 CNT 海绵在 X 波段显示出高度的 EMI 屏蔽效率 (SE) 和比 SE (SSE)，分别为 54.8 dB 和 5480 dB cm3/g。通过增加样品的厚度或密度，可以进一步提高碳纳米管海绵的性能。通过直接渗透法与PDMS复合后，CNT/PDMS薄膜在厚度为2.0 mm时仍表现出优异的EMI SE（46.3 dB），而CNT负载量小于1.0 wt%。在重复拉伸或弯曲 1000 次循环后，复合材料的 EMI SE 几乎没有变化。这种柔性、稳定性和高导电性的纳米复合材料可直接用作封装、电子和通信等领域的高性能 EMI 屏蔽膜。