A method for scalable synthesis of epoxy composites with graphene and few‐layer graphene fillers is described, and the electromagnetic interference (EMI) shielding and thermal properties of such composites at elevated temperatures are reported. The tested materials reveal excellent total EMI shielding of SE_T ≈ 65 dB (≈ 105 dB) at a thickness of 1 mm (≈ 2 mm) in the X‐band frequency range. At higher filler loading fractions, composites reveal a room‐temperature cross‐plane thermal conductivity of 11.2 ± 0.9 Wm⁻¹ K⁻¹, which is a factor of ×41 larger than that of the pristine epoxy. Interestingly, the EMI shielding efficiency improves further as the temperature increases while the thermal conductivity remains approximately constant. The enhancement in the EMI shielding is explained by the temperature dependence of the two electrical conduction mechanisms, electronic band‐type conduction inside the fillers, and hopping conduction between the fillers. The excellent EMI shielding and heat conduction characteristics of such multifunctional graphene composites at high temperatures are promising for packaging applications of microwave components where EMI shielding and thermal management are important design considerations.

中文翻译：

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高温下电磁屏蔽和热管理的多功能石墨烯复合材料

描述了一种可扩展合成具有石墨烯和少量石墨烯填料的环氧复合材料的方法，并报道了此类复合材料在高温下的电磁干扰（EMI）屏蔽和热性能。所测试的材料揭示SE的优良总EMI屏蔽_Ť的厚度在X波段频率范围为1毫米（≈2mm）的≈65分贝（≈105分贝）。在较高的填料含量下，复合材料的室温横断面导热系数为11.2±0.9 Wm ^-1  K ^-1，比原始环氧树脂大41倍。有趣的是，EMI屏蔽效率随着温度的升高而进一步提高，而热导率保持大致恒定。EMI屏蔽的增强可以通过两种导电机制的温度依赖性来解释：填充物内部的电子带型传导以及填充物之间的跳跃传导。这种多功能石墨烯复合材料在高温下的优异的EMI屏蔽和导热特性对于微波组件的包装应用是有前途的，其中EMI屏蔽和热管理是重要的设计考虑因素。