Abstract We have explored the sulfonic-functionalized graphene oxides (S-GOs) as an efficient conductive reinforcement to enhance the dielectric permittivity and electromagnetic interference (EMI) shielding effectiveness of the polyethersulfone (PES). The S-GOs having numerous terminal -SO3− groups not only promote the homogeneous dispersion for achieving the low percolation threshold, but also induce strong H-bonding and dipole–dipole interactions at the interfaces. As-prepared S-GO nanosheets showed uniform dispersion in PES matrix with strong adhesion with the polymer matrix via non-bonding interactions. The remarkable enhancement of dielectric permittivity of PES upon inclusion of S-GOs could be attributed to the interfacial polarization effect and microcapacitor model. As-prepared nanocomposites exhibited low conductive percolation threshold. The well-wrapped graphene nanosheets by thin PES layer prevented direct contact of graphene nanosheets and consequently decreased the dielectric loss by suppressing the current leakage. The PES/S-GO nanocomposites exhibited significant improvement in thermal stability with high char yield in N2 atmosphere compared to pure PES. A high EMI shielding effectiveness of 23.5 dB was achieved for the nanocomposite film with 5 wt% graphene loading, which might be originated from the development of conductive network at higher graphene loading. Overall, the as-prepared PES/S-GO hybrid nanocomposite could be used in DC and radiofrequency electronics.

中文翻译：

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具有增强的介电常数和 EMI 屏蔽效果的磺酸基功能化氧化石墨烯增强聚醚砜纳米复合材料 

摘要 我们探索了磺酸官能化氧化石墨烯 (S-GO) 作为一种有效的导电增强材料，以提高聚醚砜 (PES) 的介电常数和电磁干扰 (EMI) 屏蔽效果。具有大量末端-SO3-基团的S-GO不仅促进均匀分散以实现低渗透阈值，而且在界面处诱导强氢键和偶极-偶极相互作用。所制备的 S-GO 纳米片在 PES 基质中表现出均匀的分散性，通过非键合相互作用与聚合物基质具有很强的粘附性。包含 S-GO 后 PES 介电常数的显着增强可归因于界面极化效应和微电容器模型。所制备的纳米复合材料表现出低导电渗透阈值。由薄 PES 层包裹良好的石墨烯纳米片防止了石墨烯纳米片的直接接触，从而通过抑制电流泄漏来降低介电损耗。与纯 PES 相比，PES/S-GO 纳米复合材料在 N2 气氛中表现出热稳定性和高炭产率的显着改善。具有 5 wt% 石墨烯负载的纳米复合膜实现了 23.5 dB 的高 EMI 屏蔽效率，这可能源于在更高石墨烯负载下导电网络的发展。总体而言，所制备的 PES/S-GO 混合纳米复合材料可用于直流和射频电子产品。与纯 PES 相比，PES/S-GO 纳米复合材料在 N2 气氛中表现出热稳定性和高炭产率的显着改善。具有 5 wt% 石墨烯负载的纳米复合膜实现了 23.5 dB 的高 EMI 屏蔽效率，这可能源于在更高石墨烯负载下导电网络的发展。总体而言，所制备的 PES/S-GO 混合纳米复合材料可用于直流和射频电子产品。与纯 PES 相比，PES/S-GO 纳米复合材料在 N2 气氛中表现出热稳定性和高炭产率的显着改善。具有 5 wt% 石墨烯负载的纳米复合膜实现了 23.5 dB 的高 EMI 屏蔽效率，这可能源于在更高石墨烯负载下导电网络的发展。总体而言，所制备的 PES/S-GO 混合纳米复合材料可用于直流和射频电子产品。