Abstract Due to intensive development in smart electronics and energy devices, wearable electromagnetic interference (EMI) shielding materials such as conducting textiles have emerged to protect human as well as sensitive electronics from electromagnetic pollution. In this work, zinc oxide (ZnO) and reduced graphene oxide (rGO) coated wearable cotton fabrics have been prepared for the application of EMI shielding effectiveness in X-band (8.2–12.4 GHz). The uniform coating of ZnO nanoparticles is achieved by the easy and cost effective in-situ sol-gel method, whereas the uniform coating of rGO is achieved by simple spraying of graphene oxide solution followed by thermal reduction. It is observed that the total EMI shielding effectiveness increases with the rGO loading, however, the reflection loss decreases owing to improved conductivity of the cotton fabric. The as-prepared rGO/ZnO coated cotton (ZnO + 7 wt% rGO) achieves highest total EMI shielding effectiveness of ~99.999% (54.7 dB), which is shared by ~17.783% of reflection and ~82.216% of absorption. Such high absorption dominant EMI shielding is attributed to highly dielectric ZnO nanoparticles, highly conductive rGO sheets and the core-shell structure of the coated cotton fabric. It is also concluded that the excessive loading of rGO can block all the pores of the cotton fabric which is not beneficial for high absorption of the electromagnetic waves. The high absorption of ~90% is demonstrated when the ZnO coated cotton is loaded with 3 wt% rGO. In this work, the detailed mechanism of such absorption dominant EMI shielding has been discussed in details.

中文翻译：

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用于高微波吸收的还原氧化石墨烯/氧化锌涂层可穿戴导电棉纺织品

摘要 由于智能电子和能源设备的密集发展，出现了可穿戴电磁干扰（EMI）屏蔽材料，如导电纺织品，以保护人类和敏感电子设备免受电磁污染。在这项工作中，已经制备了氧化锌 (ZnO) 和还原氧化石墨烯 (rGO) 涂层的可穿戴棉织物，用于在 X 波段 (8.2-12.4 GHz) 中应用 EMI 屏蔽效果。ZnO 纳米粒子的均匀涂层是通过简单且具有成本效益的原位溶胶-凝胶方法实现的，而 rGO 的均匀涂层是通过简单地喷涂氧化石墨烯溶液然后热还原来实现的。据观察，总 EMI 屏蔽效能随着 rGO 负载的增加而增加，然而，由于棉织物的导电性提高，反射损失减少。所制备的 rGO/ZnO 涂层棉 (ZnO + 7 wt% rGO) 实现了最高的总 EMI 屏蔽效率~99.999% (54.7 dB)，由~17.783% 的反射和~82.216% 的吸收共享。这种以高吸收为主的 EMI 屏蔽归因于高介电的 ZnO 纳米粒子、高导电的 rGO 片和涂层棉织物的核壳结构。还得出结论，rGO 的过量负载会阻塞棉织物的所有孔隙，这不利于电磁波的高吸收。当 ZnO 涂层棉负载 3 wt% rGO 时，显示出约 90% 的高吸收率。在这项工作中，详细讨论了这种以吸收为主的 EMI 屏蔽的详细机制。所制备的 rGO/ZnO 涂层棉 (ZnO + 7 wt% rGO) 实现了最高的总 EMI 屏蔽效率~99.999% (54.7 dB)，由~17.783% 的反射和~82.216% 的吸收共享。这种以高吸收为主的 EMI 屏蔽归因于高介电的 ZnO 纳米粒子、高导电的 rGO 片和涂层棉织物的核壳结构。还得出结论，rGO 的过量负载会阻塞棉织物的所有孔隙，这不利于电磁波的高吸收。当 ZnO 涂层棉负载 3 wt% rGO 时，显示出约 90% 的高吸收率。在这项工作中，详细讨论了这种以吸收为主的 EMI 屏蔽的详细机制。所制备的 rGO/ZnO 涂层棉 (ZnO + 7 wt% rGO) 实现了最高的总 EMI 屏蔽效率~99.999% (54.7 dB)，由~17.783% 的反射和~82.216% 的吸收共享。这种以高吸收为主的 EMI 屏蔽归因于高介电的 ZnO 纳米粒子、高导电的 rGO 片和涂层棉织物的核壳结构。还得出结论，rGO 的过量负载会阻塞棉织物的所有孔隙，这不利于电磁波的高吸收。当 ZnO 涂层棉负载 3 wt% rGO 时，显示出约 90% 的高吸收率。在这项工作中，详细讨论了这种以吸收为主的 EMI 屏蔽的详细机制。