Although graphene nanosheets (GNs) with huge specific surface area and exceptional electrical properties exhibit attractive practical prospect in the realm of electromagnetic function materials, how to optimize the distribution states of GNs in matrix is still a challenge. In this work, the suspension of GNs was prepared directly via an efficient liquid-phase exfoliation (LPE) process in N-octyl-2-pyrrolidone (NOP). Thanks to the dissolution of polyether sulfone (PES) in NMP and NOP solvent, the GNs/PES composites were in-situ prepared via a facile solution blending in combination with evaporation process. The “function units” of the mesoscopic micro-cluster structure assembled by GNs during the solvent evaporation process contribute to optimized impedance matching characteristics and loss capabilities as well as excellent electromagnetic wave (EMW) absorbing performance of the as-constructed GNs/PES electromagnetic composites. Particularly, the as-prepared sample G-P-9 with a graphene content of as low as 9.0 wt% exhibits outstanding EMW absorbing performance in the whole ranges of tested frequency (8.2–12.4 GHz) and temperature (293–453 K) with a minimum reflection loss (RL) of −52.7 dB. Besides, the in-situ self-assemble GNs/single-walled carbon nanotubes (GNs/SWCNT) film with pre-constructed three-dimensional interpenetrating conductive network exhibits excellent electromagnetic interference (EMI) shielding effectiveness (SE) of about 5.1 × 10 dB cm g. The present approach would be applicable to construct high-performance electromagnetic functional materials and broaden the application prospect of high-integrity graphene nanosheets.

中文翻译：

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基于液相剥离策略原位构建高效电磁功能石墨烯/PES复合材料

尽管具有巨大比表面积和优异电性能的石墨烯纳米片（GNs）在电磁功能材料领域展现出诱人的实用前景，但如何优化GNs在基体中的分布状态仍然是一个挑战。在这项工作中，GNs 的悬浮液是通过 N-辛基-2-吡咯烷酮 (NOP) 中的高效液相剥离 (LPE) 工艺直接制备的。由于聚醚砜（PES）在 NMP 和 NOP 溶剂中的溶解，GNs/PES 复合材料是通过简单的溶液混合结合蒸发过程原位制备的。 GNs在溶剂蒸发过程中组装的介观微团簇结构的“功能单元”有助于优化阻抗匹配特性和损耗能力以及所构建的GNs/PES电磁复合材料优异的电磁波（EMW）吸收性能。特别是，所制备的石墨烯含量低至 9.0 wt% 的样品 GP-9 在整个测试频率（8.2–12.4 GHz）和温度（293–453 K）范围内表现出出色的电磁波吸收性能，最小反射损耗 (RL) 为 −52.7 dB。此外，具有预构建三维互穿导电网络的原位自组装GNs/单壁碳纳米管（GNs/SWCNT）薄膜表现出优异的电磁干扰（EMI）屏蔽效能（SE），约为5.1×10 dB厘米克。该方法可用于构建高性能电磁功能材料并拓宽高完整性石墨烯纳米片的应用前景。