Metal-based electromagnetic interference(EMI)shielding composites are essential for ensuring electromagnetic compatibility but are often compromised by susceptibility to corrosion,especially in harsh environments.Exis...Metal-based electromagnetic interference(EMI)shielding composites are essential for ensuring electromagnetic compatibility but are often compromised by susceptibility to corrosion,especially in harsh environments.Existing strategies to mitigate coupling corrosion typically involve physical barriers,which inevitably hinder conductivity.In this study,we introduce a novel interface doping approach to fabricate lightweight Graphite@PDA/Ag@Ag composites that simultaneously enhance EMI shielding and corrosion resistance.The PDA/Ag layer selectively regulates electrons with different migration directions and energies to migrate,increasing charge transfer resistance at Ag/graphite interfaces and ensuring conductivity through a tunneling effect.This design achieves an ultralow corrosion rate of 4.313×10–8µm/y(a billionth that of 316 L stainless steel)alongside superior EMI shielding effectiveness of 109 dB in the X-band at 1.5 mm thickness.Remarkably,the composite maintains over 90 dB shielding efficiency after 7 d in NaCl solutions across various pH levels.Furthermore,simulated corrosion under South China Sea conditions predicts a coating loss of less than 0.026µm over 7 years.This work presents a transformative approach to mitigating coupling corrosion in EMI shielding materials,offering a practical route to high-performance,corrosion-resistant composites without the need for a protective topcoat.展开更多
Dielectric-magnetic composite material that incorporate both dielectric and magnetic loss mechanisms are progressively emerging as the design paradigm for high-performance electromagnetic wave(EMW)absorbing materials....Dielectric-magnetic composite material that incorporate both dielectric and magnetic loss mechanisms are progressively emerging as the design paradigm for high-performance electromagnetic wave(EMW)absorbing materials.However,it remains challenging to combine dielectric and magnetic materials through a convenient structural design.Here,we report a core-shell structured Fe_(3)O_(4)@copper sulfide with multiple loss mechanisms,combining the typical magnetic component Fe_(3)O_(4),which has excellent magnetic loss and impedance matching,with the dielectric component copper sulfide,which has high electrical conductivity and rich interfaces.Unlike the conventional hydrothermal synthesis method,the Fe_(3)O_(4)@copper sulfide core-shell structure is formed using the polymer-assisted electrodeless metal deposition(PAMD)method and a subsequent solution based sulfidation reaction.Attributed to the strong dielectric loss capacity introduced by copper sulfide nanosheets,Fe_(3)O_(4)@copper sulfide has an effective absorption bandwidth(EAB)of 5 GHz within 2-18 GHz at a filling ratio of 65 wt.%and a thickness of only 1.4 mm.In addition,we used the same possess to synthesize FeSiCr@copper sulfide,which also exhibited EMW absorption performance superior to that of the original magnetic component,verifying that the PAMD method is also applicable to other magnetic particles.Therefore,the proposed PAMD method provides a new solution-based strategy for constructing high-performance EMW absorbing materials with multi-component and multi-loss mechanisms.展开更多
基金supported by the National Science and Technology Major Project(No.J2019-VI-0015-013)Innovative Talent Promotion Program-Youth Science and Technology Emerging Project(No.2021KJXX-101)+5 种基金Science Fund for Distinguished Young Scholars of Shannxi Province(No.2023-JC-JQ-35)Fundamental Research Project of National Defense(No.2021-JCJQ-ZD-046-00)Northwestern Polytechnical University College Student Innovation and Entrepreneurship Training Program(No.S202310699574)National Natural Science Foundation of China(No.52302367)“Fundamental Research Funds for the Central Universities”(No.G2023KY05101)Special thanks to Dr.Minghui Fang(School of Materials Science and Engineering,Northwestern Polytechnical Uni-versity)for illustration production.
文摘Metal-based electromagnetic interference(EMI)shielding composites are essential for ensuring electromagnetic compatibility but are often compromised by susceptibility to corrosion,especially in harsh environments.Existing strategies to mitigate coupling corrosion typically involve physical barriers,which inevitably hinder conductivity.In this study,we introduce a novel interface doping approach to fabricate lightweight Graphite@PDA/Ag@Ag composites that simultaneously enhance EMI shielding and corrosion resistance.The PDA/Ag layer selectively regulates electrons with different migration directions and energies to migrate,increasing charge transfer resistance at Ag/graphite interfaces and ensuring conductivity through a tunneling effect.This design achieves an ultralow corrosion rate of 4.313×10–8µm/y(a billionth that of 316 L stainless steel)alongside superior EMI shielding effectiveness of 109 dB in the X-band at 1.5 mm thickness.Remarkably,the composite maintains over 90 dB shielding efficiency after 7 d in NaCl solutions across various pH levels.Furthermore,simulated corrosion under South China Sea conditions predicts a coating loss of less than 0.026µm over 7 years.This work presents a transformative approach to mitigating coupling corrosion in EMI shielding materials,offering a practical route to high-performance,corrosion-resistant composites without the need for a protective topcoat.
基金supported by the National Natural Science Foundation of China(Nos.52302367 and 52203094)the National Key Laboratory of Electromagnetic Information Control and Effects Open Fund(No.SYS1W2023010304)+1 种基金the State Key Laboratory of Solidification Processing in NPU(No.2025-TS-08)We are grateful to Gao Qianwen(Analytical&Testing Center of NPU)for her help in the microstructure characterization.
文摘Dielectric-magnetic composite material that incorporate both dielectric and magnetic loss mechanisms are progressively emerging as the design paradigm for high-performance electromagnetic wave(EMW)absorbing materials.However,it remains challenging to combine dielectric and magnetic materials through a convenient structural design.Here,we report a core-shell structured Fe_(3)O_(4)@copper sulfide with multiple loss mechanisms,combining the typical magnetic component Fe_(3)O_(4),which has excellent magnetic loss and impedance matching,with the dielectric component copper sulfide,which has high electrical conductivity and rich interfaces.Unlike the conventional hydrothermal synthesis method,the Fe_(3)O_(4)@copper sulfide core-shell structure is formed using the polymer-assisted electrodeless metal deposition(PAMD)method and a subsequent solution based sulfidation reaction.Attributed to the strong dielectric loss capacity introduced by copper sulfide nanosheets,Fe_(3)O_(4)@copper sulfide has an effective absorption bandwidth(EAB)of 5 GHz within 2-18 GHz at a filling ratio of 65 wt.%and a thickness of only 1.4 mm.In addition,we used the same possess to synthesize FeSiCr@copper sulfide,which also exhibited EMW absorption performance superior to that of the original magnetic component,verifying that the PAMD method is also applicable to other magnetic particles.Therefore,the proposed PAMD method provides a new solution-based strategy for constructing high-performance EMW absorbing materials with multi-component and multi-loss mechanisms.
