1成果简介 

　　随着人们对电磁辐射潜在健康风险日益关注，开发高效且环保的电磁干扰（EMI）屏蔽材料变得愈发重要。在吸收主导的屏蔽系统中，性能提升主要源于介电损耗和磁损耗的协同作用，而三维多孔结构则有效促进了电磁波在内部的衰减。本文，南方科技大学田颜清教授等在《ACS Applied Engineering Materials》期刊发表名为"Design and Fabrication of Porous Polymer Gels Composites with Enhanced Electromagnetic Interference Shielding Performance"的论文，研究通过多巴胺辅助化学镀工艺在石墨烯纳米片上沉积镍，随后将碳纤维（CF）和镍包覆石墨烯纳米片（GNP@PDA@Ni）引入聚乙烯醇（PVA）基质中，构建了柔性PVA/CF/GNP@PDA@Ni（PCGN）多孔聚合物凝胶体系。

　　实验结果表明，PCGN-15凝胶在X波段实现了45 dB的EMI屏蔽效能，且以吸收主导（A/R > 1）。进一步增加填料含量后，PCGN-25复合材料的屏蔽效能高达75 dB，可有效阻挡99.99%的微波辐射，满足射频器件和电子通信领域的严苛要求。值得注意的是，PCGN聚合物凝胶还展现出 robust 的机械性能，其断裂伸长率高达264%，拉伸强度达273 kPa，并在低温（−20 °C）下保持出色的柔性，表明其适用于多样化的环境条件。这些特性共同突显了该材料在未来先进电磁防护系统和新兴柔性电子技术中的部署潜力。

　　2图文导读

　　图1. Preparation route for (a) GNP@PDA@Ni and (b) PCGN composites.

　　图2. (a) Magnetic response of GNP and GNP@PDA@Ni to a magnet; (b) Hysteresis loop of GNP@PDA@Ni; (c) FTIR spectra of GNP and GNP@PDA; (d) XRD patterns of GNP and GNP@PDA@Ni; (e) XPS survey spectra of GNP and GNP@PDA@Ni; (f) HRTEM Image of the GNP@PDA@Ni Composite Showing the Ni (111) Lattice Fringe; (g,h) SEM images and corresponding Ni, C EDS elemental mappings of GNP@PDA@Ni.

　　图3. (a) SEM image of original GNPs; (b) magnified image of GNPs; (c) SEM image of GNP@PDA; (d) magnified image of GNP@PDA; (e) SEM image of GNP@PDA@Ni; (f) magnified image of GNP@PDA@Ni.

　　图4. (a–c), (e) SEM images of PCGN-15; (d,f) EDS elemental mappings for Ni and C in the corresponding regions of PCGN-15.

　　图5. (a) Image of PCGN-25 during compression; (b) schematic diagram of the superelastic mechanism of PCGN-25; (c) image of deformation of PCGN-25; (d) compressive stress–strain curve of PCGN-15; (e) Tensile stress–strain curve for PCGN 0–25; (f) comparison of PCGN-25 gel and hydrogel after 1 week of storage in this study.

　　图6. (a) Investigation of the Effect of Filler Content (0–25%) on the Electromagnetic Shielding Performance of PCGN (Sample thickness: 4 mm); (b) SET, SEA, and SER of PCGN (0–25) Gel; (c) reflection (R), absorption (A), and transmission (T) coefficients of PCGN (0–25) gel (d) exploration of the Ratio of GNP@PDA@Ni to CF in PCGN-25 Gel (sample thickness: 4 mm); (e) electromagnetic shielding effect of PCGN-25 gel at different thicknesses; (f) changes in electromagnetic shielding performance and mass of the PCGN-25 gel over 10 days; (g) schematic diagram of PCGN Gel’s electromagnetic shielding mechanism; (h) electromagnetic power loss density distribution of PCGN-0 and PCGN-25 polymer gels; (i) comparison of electromagnetic interference (EMI) performance of the PCGN-25 Gel with Other Reported Materials.

　　3小结 

　　综上所述，本研究通过多巴胺辅助化学镀工艺在石墨烯纳米片上沉积镍，并结合碳纤维与PVA基质，成功构建了柔性PVA/CF/GNP@PDA@Ni多孔聚合物凝胶体系。该材料在X波段展现出优异的EMI屏蔽性能：PCGN-15实现45 dB的屏蔽效能并以吸收主导，PCGN-25的屏蔽效能高达75 dB，可有效阻挡99.99%的微波辐射，满足高端电子通信需求。同时，PCGN凝胶兼具出色的机械性能（断裂伸长率264%、拉伸强度273 kPa）和低温柔性（−20 °C），适用于复杂环境。该工作通过"介电-磁损耗协同"与"三维多孔结构"的双重策略，为柔性高效EMI屏蔽材料的设计提供了新思路，在先进电磁防护和柔性电子领域具有广阔应用前景。

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