3D Printed Integrated Gradient-Conductive MXene/CNT/Polyimide Aerogel Frames for Electromagnetic Interference Shielding with Ultra-Low Reflection

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Фев. 8, 2023

Construction of advanced electromagnetic interference (EMI) shielding materials with miniaturized, programmable structure and low reflection are promising but challenging. Herein, an integrated transition-metal carbides/carbon nanotube/polyimide (gradient-conductive MXene/CNT/PI, GCMCP) aerogel frame hierarchical porous gradient-conductivity has been constructed to achieve EMI ultra-low reflection. The gradient-conductive structures obtained by continuous 3D printing MXene/CNT/poly (amic acid) inks different CNT contents, where the slightly conductive top layer serves as EM absorption highly bottom layer. In addition, could extend dissipation path dissipate multiple reflections. Consequently, GCMCP frames exhibit excellent average efficiency (68.2 dB) (R = 0.23). Furthermore, miniaturized can be used gaskets effectively block wireless power transmission, which shows a prosperous application prospect in defense industry aerospace.

Язык: Английский

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NiO/Ni Heterojunction on N‐Doped Hollow Carbon Sphere with Balanced Dielectric Loss for Efficient Microwave Absorption

Small, Год журнала: 2023, Номер 19(12)

Опубликована: Янв. 1, 2023

Hollow carbon spheres are potential candidates for lightweight microwave absorbers. However, the skin effect of pure carbon-based materials frequently induces a terrible impedance mismatching issue. Herein, small-sized NiO/Ni particles with heterojunctions on N-doped hollow (NHCS@NiO/Ni) constructed using SiO2 as sacrificing template. The fabricated NHCS@NiO/Ni displayed excellent absorbability minimum reflection loss -44.04 dB matching thickness 2 mm and wider efficient absorption bandwidth 4.38 GHz 1.7 mm, superior to most previously reported Experimental results demonstrated that property attributed balanced dielectric optimized characteristic due presence heterojunctions. Theoretical calculations suggested redistribution charge at interfaces formation dipoles induced by N dopants defects responsible enhanced conduction polarization losses NHCS@NiO/Ni. simulations surface current power densities reveal has- applicable attenuation ability toward under practical application scenario. This work paves an way reasonable design well-defined nanostructures high-efficiency absorption.

Язык: Английский

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Functional Tailoring of Multi‐Dimensional Pure MXene Nanostructures for Significantly Accelerated Electromagnetic Wave Absorption

Small, Год журнала: 2023, Номер 19(41)

Опубликована: Июнь 8, 2023

Transition metal carbide (Ti3 C2 Tx MXene), with a large specific surface area and abundant functional groups, is promising candidate in the family of electromagnetic wave (EMW) absorption. However, high conductivity MXene limits its EMW absorption ability, so it remains challenge to obtain outstanding attenuation ability pure MXene. Herein, by integrating HF etching, KOH shearing, high-temperature molten salt strategies, layered (L-MXene), network-like nanoribbons (N-MXene NRs), porous monolayer (P-MXene ML), layer L) are rationally constructed favorable microstructures states for HF, KOH, KCl/LiCl used functionalize tune microstructure state (F- , OH- Cl- terminals), thereby improving capacity MXene-based nanostructures. Impressively, unique structure, proper electrical conductivity, area, defects, nanostructures achieve good impedance matching, dipole polarization, conduction loss, thus inheriting excellent performance. Consequently, L-MXene, N-MXene NRs, P-MXene ML, L enable reflection loss (RL ) value -43.14, -63.01, -60.45, -56.50 dB matching thickness 0.95, 1.51, 3.83, 4.65 mm, respectively.

Язык: Английский

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Electrospinning of hierarchical carbon fibers with multi-dimensional magnetic configurations toward prominent microwave absorption

Carbon, Год журнала: 2022, Номер 202, С. 244 - 253

Опубликована: Ноя. 1, 2022

Язык: Английский

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Sequential Architecture Induced Strange Dielectric‐Magnetic Behaviors in Ferromagnetic Microwave Absorber

Advanced Functional Materials, Год журнала: 2023, Номер 33(27)

Опубликована: Март 27, 2023

Abstract The high filler loading (FL) is a bottleneck in developing lightweight ferromagnetic microwave absorbers (MAs) for the actual applications. Sequential architecture design of MAs can induce strange physical behaviors due to unique coupling‐enhancement effect between functional units, providing vast potential achieving absorption performance. However, FLs current sequential fail be designed on demand because dielectric‐magnetic cannot fulfilled. influence engineering macroscopic properties or microscopic loss mechanism still needs more exploration. Herein, based four mesoscopic models (particles, chains, bundles, and fibers) series with different architectures are prepared via bottom‐up self‐assembly method. fibrous samples exhibit best performance (−51.3 dB, 4.12 GHz) at breakthrough FL 2 wt%, which one order magnitude less than other MAs. Strange behaviors, including negative permittivity heterodromous chiral vortex, occur units lateral configurations. Further, special established reveal attenuation evolutionary mechanism. This study clarifies relationship provides new sight understand electromagnetic

Язык: Английский

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Construction of dual heterogeneous interface between zigzag-like Mo–MXene nanofibers and small CoNi@NC nanoparticles for electromagnetic wave absorption

Journal of Advanced Ceramics, Год журнала: 2023, Номер 12(8), С. 1562 - 1576

Опубликована: Май 24, 2023

Two-dimensional (2D) transition metal carbides (MXene) process attractive conductivity and abundant surface functional groups, providing immense potential in the field of electromagnetic wave (EMW) absorption. However, high spontaneous aggregation MXene suffer from limited EMW response. Inspired by dielectric-magnetic synergy effect, strategy decorating with magnetic elements is expected to solve this challenge. In work, zigzag-like Mo₂TiC₂ nanofiber (Mo-MXene NFs) cross-linked networks are fabricated using HF etching KOH shearing processes. Subsequently, Co-MOF derived CoNi LDH ultrathin nanosheets grown inside Mo-MXene NFs, N-doped carbon matrix anchored alloy nanoparticles formed pyrolysis firmly embedded NFs network. Benefiting synergistic effect highly dispersed small nanoparticles, a 3D conductive network assembled numerous hollow vesicles, dual heterogeneous interface, designed Mo-MXene/CoNi-NC heterostructure provides robust absorption ability reflection loss (R_L) value -68.45 dB at matching thickness 4.38 mm. The performance can be attributed excellent dielectric losses, loss, impedance matching, multiple scattering triggered unique structure. This work puts up great developing advanced MXene-based devices.

Язык: Английский

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Metal–Organic Gel Leading to Customized Magnetic-Coupling Engineering in Carbon Aerogels for Excellent Radar Stealth and Thermal Insulation Performances

Nano-Micro Letters, Год журнала: 2023, Номер 16(1)

Опубликована: Дек. 4, 2023

Metal-organic gel (MOG) derived composites are promising multi-functional materials due to their alterable composition, identifiable chemical homogeneity, tunable shape, and porous structure. Herein, stable metal-organic hydrogels prepared by regulating the complexation effect, solution polarity curing speed. Meanwhile, collagen peptide is used facilitate fabrication of a aerogel with excellent physical properties as well homogeneous dispersion magnetic particles during calcination. Subsequently, two kinds heterometallic coupling systems obtained through application Kirkendall effect. FeCo/nitrogen-doped carbon (NC) demonstrates an ultra-strong microwave absorption - 85 dB at ultra-low loading 5%. After reducing time taken atom shifting, FeCo/Fe

Язык: Английский

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Macroscopic electromagnetic synergy network-enhanced N-doped Ni/C gigahertz microwave absorber with regulable microtopography

Nano Research, Год журнала: 2023, Номер 16(7), С. 10666 - 10677

Опубликована: Апрель 29, 2023

Язык: Английский

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Integrated Electromagnetic Device with On‐Off Heterointerface for Intelligent Switching Between Wave‐Absorption and Wave‐Transmission

Advanced Functional Materials, Год журнала: 2023, Номер 33(49)

Опубликована: Июль 20, 2023

Abstract Intelligent electromagnetic wave absorbers (IEAs) are in high demand due to their dynamic parameters that can adapt the complex and volatile application environments of current 5G era. Despite this, there is currently a lack research on convertible (EMW) absorption mode (switching between wave‐absorption wave‐transmission) integrated design with external physical stimulations, so device will realize intelligent switching any conditions. In this work, V 2 C‐VO (M) heterostructure exhibits reversible metal–insulator transition at temperature 62 °C fabricated via oxidation MXene. The heterostructures demonstrate near wave‐transmission characteristics 25 while behavior wide effective bandwidth (4.04 GHz) 70 °C. VO stronger intrinsic conductivity after phase transition, “on‐off” C lead poor/strong local conductive network interfacial polarization 25/70 °C, thus creating “quantized” dielectric loss. Furthermore, multilayered functional developed facilitate absorber's voltage 17.5 V. This work presents promising opportunities for various applications, including radar stealth, portable stealth suits, signal regulation, deicing.

Язык: Английский

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Fabrication of CuS/Fe3O4@polypyrrole flower-like composites for excellent electromagnetic wave absorption

Journal of Colloid and Interface Science, Год журнала: 2022, Номер 634, С. 481 - 494

Опубликована: Дек. 9, 2022

Язык: Английский

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