Deployable satellites in space are exposed to high-frequency electromagnetic interference (EMI) for long periods of time, resulting in shortened lifetimes, so there is an urgent need for supportive electromagnetic shielding materials. To address this limitation, our team has developed innovative ultrathin carbon nanofiber/reduced graphene oxide/polyimide (CNF/rGO/PI) composites. It has excellent strength, shape memory properties, thermal stability and wide temperature range tolerance. Among them, polyimide with 4 % CNFs and 4 % rGO (CGPI44) has the best performance. Gradient-thick Ag films are deposited on both sides of the CGPI44 substrate by magnetron sputtering to form sandwich structure composites. With a sputtered Ag thickness of only about 5 μm and a total thickness of 0.146 mm, the material exhibited an extremely high electrical conductivity and excellent EMI shielding effectiveness (SE) of up to 112 dB in the 8.2–12.4 GHz band. Finite element analysis is performed to calculate the electric field strength and energy distribution. By providing a feasible scheme for highly effective shielding of high-frequency EMI, this approach will promote research on magnetron-sputtered polymer composites in the field of electromagnetic shielding.

中文翻译：

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在CNF/rGO/聚酰亚胺表面沉积梯度厚度银膜，形成三明治结构，实现高效电磁干扰屏蔽

太空中的可部署卫星长期暴露在高频电磁干扰（EMI）下，导致其寿命缩短，因此迫切需要支持性的电磁屏蔽材料。为了解决这一限制，我们的团队开发了创新的超薄碳纳米纤维/还原氧化石墨烯/聚酰亚胺（CNF/rGO/PI）复合材料。它具有优异的强度、形状记忆特性、热稳定性和宽温度范围耐受性。其中，含有4% CNFs和4% rGO的聚酰亚胺（CGPI44）的性能最好。通过磁控溅射在 CGPI44 基板的两侧沉积梯度厚的 Ag 薄膜，形成三明治结构复合材料。该材料的溅射Ag厚度仅为约5μm，总厚度为0.146mm，表现出极高的导电率和优异的EMI屏蔽效能（SE），在8.2-12.4GHz频段高达112dB。进行有限元分析来计算电场强度和能量分布。该方法为高效屏蔽高频EMI提供了可行的方案，将推动磁控溅射聚合物复合材料在电磁屏蔽领域的研究。