MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, Shaanxi Key Laboratory of Macromolecular Science and Technology, Department of Applied Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi' an, Shaanxi 710072, P.R. China.
Nanoscale. 2019 Nov 28;11(46):22590-22598. doi: 10.1039/c9nr06022g.
How to significantly increase electromagnetic interference (EMI) shielding performances by improving electrical conductivities is still a serious challenge. Herein, we have explored and prepared a 3D silver platelets/reduced graphene oxide foam (AgPs/rGF) with numerous regular spherical hollow structures, which ingeniously achieved uniform dispersion of the AgPs along the 3D rGO network via the sol-gel template method. Combining AgPs/rGF with epoxy resin (EP), 3D AgPs/rGF/EP nanocomposites with highly regular segregated structures were successfully fabricated. Due to interconnected spherical hollow conductive networks of the AgPs/rGF and the interfacial synergy between AgPs/rGF and EP, the 3D AgPs/rGF/EP nanocomposites containing 0.44 vol% rGF and 0.94 vol% AgPs show the maximum EMI shielding effectiveness (SE) value of 58 dB in the X-band (shielding 99.9998% of incident electromagnetic waves), 274% improvement in comparison with that of 3D rGF/EP nanocomposites (∼21 dB). The corresponding electrical conductivity improves from 0.1 to 45.3 S m-1, and the dielectric loss increases from ∼0.6 to ∼0.8. In addition, the theoretical minimum skin depth of the 3D AgPs/rGF/EP nanocomposites is calculated by analyzing the skin effect. It provides a guideline for fabricating lightweight, thin and multi-functional shielding nanocomposites in the key fields of spacecraft and high precision electronics.
如何通过提高电导率来显著提高电磁干扰（EMI）屏蔽性能仍然是一个严峻的挑战。在此，我们探索并制备了一种具有大量规则球形空心结构的 3D 银片/还原氧化石墨烯泡沫（AgPs/rGF），巧妙地通过溶胶-凝胶模板法实现了 AgPs 在 3D rGO 网络中的均匀分散。将 AgPs/rGF 与环氧树脂（EP）结合，成功制备了具有高度规则分离结构的 3D AgPs/rGF/EP 纳米复合材料。由于 AgPs/rGF 的互连球形空心导电网络和 AgPs/rGF 与 EP 之间的界面协同作用，含有 0.44 体积% rGF 和 0.94 体积% AgPs 的 3D AgPs/rGF/EP 纳米复合材料在 X 波段（屏蔽 99.9998%入射电磁波）下表现出最大的 EMI 屏蔽效能（SE）值为 58 dB，与 3D rGF/EP 纳米复合材料（约 21 dB）相比提高了 274%。相应的电导率从 0.1 提高到 45.3 S m-1，介电损耗从约 0.6 提高到约 0.8。此外，通过分析趋肤效应，计算了 3D AgPs/rGF/EP 纳米复合材料的理论最小皮肤深度。它为在航天器和高精度电子等关键领域制造轻量、薄型和多功能屏蔽纳米复合材料提供了指导。
