Abstract In this work, the low-density, compressible and porous composites are fabricated by simply coating polyurethane (PU) sponge with reduced graphene oxide (rGO) and hematite (Fe2O3) hollow microspheres for the application of absorption-dominant electromagnetic interference (EMI) shielding composites in X-band (8.2–12.4 GHz). By coating rGO on the skeleton of PU sponge, the composites possess high EMI shielding effectiveness of 37.45 dB. By further incorporating Fe2O3 hollow microspheres as the coating material along with rGO, the absorption of the electromagnetic waves enhances from 72.6% to 94.5% owing to the enhanced dielectric loss and better impedance matching at the air/shield interface. Moreover, the porous structure of the coated sponge facilitates absorption-dominant EMI shielding effectiveness owing to low density, conduction loss, multiple reflections and scattering of EM waves. In addition, the layered structure can further improve the absorption of the electromagnetic waves up to 97.3% by selectively stacking the rGO coated and rGO/Fe2O3 coated sponges, which serve as reflection and absorption layers, respectively.

中文翻译：

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用于柔性电磁干扰屏蔽复合材料的还原氧化石墨烯/Fe2O3空心微球包覆海绵

摘要 在这项工作中，通过简单地用还原氧化石墨烯 (rGO) 和赤铁矿 (Fe2O3) 中空微球涂覆聚氨酯 (PU) 海绵制备低密度、可压缩和多孔复合材料，用于吸收主导电磁干扰 (EMI) X 波段 (8.2–12.4 GHz) 中的屏蔽复合材料。通过在 PU 海绵骨架上涂覆 rGO，复合材料具有 37.45 dB 的高 EMI 屏蔽效率。通过进一步将 Fe2O3 空心微球与 rGO 一起作为涂层材料，电磁波的吸收率从 72.6% 提高到 94.5%，这是由于介电损耗的增加和空气/屏蔽界面处更好的阻抗匹配。此外，涂层海绵的多孔结构由于密度低、传导损失、EM 波的多次反射和散射。此外，通过选择性堆叠分别作为反射层和吸收层的 rGO 涂层和 rGO/Fe2O3 涂层海绵，层状结构可以进一步提高电磁波的吸收率，高达 97.3%。