Clarification of basic concepts for electromagnetic interference shielding effectiveness

Journal of Applied Physics, Journal Year: 2021, Volume and Issue: 130(22)

Published: Dec. 10, 2021

There exists serious miscomprehension in the open literature about electromagnetic interference shielding effectiveness (EMI SE) as a critical index to evaluate performance, which is misleading graduates and newcomers embarking on field of materials. EMI SE defined sum three terms including reflection loss, absorption loss multiple classical Schelkunoff theory, while it decomposed into two named practice, called Calculation theory here. In this paper, we elucidate widely-seen misconceptions connected with via theoretical derivation instance analysis. Firstly, are often mistakenly regarded approximation same names when negligible. Secondly, insufficient unreasonable determine absorption-dominant performance case that higher than since cannot represent actual levels reflected absorbed power. Power coefficients recommended compare contribution performance. Thirdly, effect included definitions reflections property clarified against commonly wrong understandings. These clarifications offer correct comprehension mechanism assessment total shielding.

Language: Английский

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Bioinspired, High-Strength, and Flexible MXene/Aramid Fiber for Electromagnetic Interference Shielding Papers with Joule Heating Performance

ACS Nano, Journal Year: 2022, Volume and Issue: 16(4), P. 6700 - 6711

Published: March 25, 2022

High-strength, flexible, and multifunctional characteristics are highly desirable for electromagnetic interference (EMI) shielding materials in the field of electric devices. In this work, inspired by natural nacre, we fabricated large-scale, layered MXene/amarid nanofiber (ANF) nanocomposite papers blade-coating process plus sol-gel conversion step. The as-synthesized possess excellent mechanical performance, that is, exceptional tensile strength (198.80 ± 5.35 MPa), large strain (15.30 1.01%), good flexibility (folded into various models without fracture), which ascribed to synergetic interactions interconnected three-dimensional network frame hydrogen bonds between MXene ANF. More importantly, with extensive continuous conductive paths formed nanosheets present a high EMI effectiveness 13188.2 dB cm2 g-1 frequency range 8.2-12.4 GHz. interestingly, show Joule heating performance fast thermal response (<10 s) low driving voltage (≤4 V). As such, large-scale MXene/ANF considered as promising alternatives wide applications management.

Language: Английский

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Porous and Ultra-Flexible Crosslinked MXene/Polyimide Composites for Multifunctional Electromagnetic Interference Shielding

Nano-Micro Letters, Journal Year: 2022, Volume and Issue: 14(1)

Published: Feb. 9, 2022

Abstract Lightweight, ultra-flexible, and robust crosslinked transition metal carbide (Ti 3 C 2 MXene) coated polyimide (PI) (C-MXene@PI) porous composites are manufactured via a scalable dip-coating followed by chemical crosslinking approach. In addition to the hydrophobicity, anti-oxidation extreme-temperature stability, efficient utilization of intrinsic conductivity MXene, interfacial polarization between MXene PI, micrometer-sized pores composite foams achieved. Consequently, show satisfactory X-band electromagnetic interference (EMI) shielding effectiveness 22.5 62.5 dB at density 28.7 48.7 mg cm −3 , leading an excellent surface-specific SE 21,317 g −1 . Moreover, exhibit electrothermal performance as flexible heaters in terms prominent, rapid reproducible, stable effect low voltages superior heat more uniform distribution compared with commercial composed alloy plates. Furthermore, well attached on human body check their electromechanical sensing performance, demonstrating sensitive reliable detection motions wearable sensors. The EMI multifunctionalities, along facile easy-to-scalable manufacturing techniques, imply promising perspectives C-MXene@PI next-generation electronics, aerospace, smart devices.

Language: Английский

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Electromagnetic interference shielding materials: recent progress, structure design, and future perspective

Journal of Materials Chemistry C, Journal Year: 2021, Volume and Issue: 10(1), P. 44 - 72

Published: Dec. 14, 2021

Novel structure design and shielding mechanism of various materials are critically reviewed. Measurement methods far-field near-field presented. Challenges future perspectives for discussed.

Language: Английский

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Thermally conductive polyvinyl alcohol composite films via introducing hetero-structured MXene@silver fillers

Nano Research, Journal Year: 2023, Volume and Issue: 16(5), P. 7820 - 7828

Published: March 15, 2023

Language: Английский

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Self-Healing Liquid Metal Magnetic Hydrogels for Smart Feedback Sensors and High-Performance Electromagnetic Shielding

Nano-Micro Letters, Journal Year: 2023, Volume and Issue: 15(1)

Published: March 31, 2023

Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli. However, are limited by challenges terms issues biocompatibility, custom shape, and self-healing. Herein, a conductive, stretchable, adaptable, self-healing, biocompatible liquid metal GaInSn/Ni-based composite hydrogel is developed incorporating magnetic into the framework through crosslinking polyvinyl alcohol (PVA) with sodium tetraborate. The excellent stretchability fast self-healing capability PVA/liquid derived from its abundant hydrogen binding sites fusion. Significantly, owing constituent, can be guided remotely using an field specific position repair broken wires no need for manual operation. also exhibits sensitive deformation responses used as strain sensor monitor body motions. Additionally, multifunctional displays absorption-dominated electromagnetic interference (EMI) shielding properties. total performance increases ~ 62.5 dB 31.8 pure PVA at thickness 3.0 mm. proposed bioinspired demonstrates substantial application intelligent devices.

Language: Английский

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Design and advanced manufacturing of electromagnetic interference shielding materials

Materials Today, Journal Year: 2023, Volume and Issue: 66, P. 245 - 272

Published: April 10, 2023

Electromagnetic interference (EMI) shielding is critical in electronic applications. However, the currently available EMI materials are restricted customizability and application flexibility. Recent advances manufacturing technologies have provided a unique path to achieve custom creation of solutions. A successful example additive (AM), which has enabled high design freedom, efficient performance regulation, multifunctionality simultaneously into fabricated shields, offering an opportunity start revolution field shielding. In this review, we summarize latest AM materials, aiming provide deep understanding connection between raw methods, considerations, performances shields. We first introduce mechanism subsequently focusing on characteristics representative methods as-created Based requirements create application-oriented solutions, these also critically compared. Thereafter, present state-of-the-art considerations shields examine pivotal roles realizing designs. conclude by discussing future research directions, at motivating use developments

Language: Английский

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Construction of NiCo2O4 nanosheets-covered Ti3C2Tx MXene heterostructure for remarkable electromagnetic microwave absorption

Carbon, Journal Year: 2022, Volume and Issue: 193, P. 26 - 34

Published: March 14, 2022

Language: Английский

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Multi-interface Assembled N-Doped MXene/HCFG/AgNW Films for Wearable Electromagnetic Shielding Devices with Multimodal Energy Conversion and Healthcare Monitoring Performances

ACS Nano, Journal Year: 2022, Volume and Issue: 16(5), P. 7816 - 7833

Published: May 10, 2022

With the progressive requirements of modern electronics, outstanding electromagnetic interference (EMI) shielding materials are extensively desirable to protect intelligent electronic equipment against EMI radiation under various conditions, while integrating functional applications. So far, it remains a great challenge effectively construct thin films with diversiform frameworks as integrated devices. To simultaneously promote waves (EMWs) attenuation and multifunction, an alternating-layered deposition strategy is designed fabricate polydimethylsiloxane packaged N-doped MXene (Ti3CNTx)/graphene oxide wrapped hollow carbon fiber/silver nanowire (p-LMHA) followed by annealing encapsulation approaches. Contributed synergistic effect consecutively conductive networks porous architectures, LMHA exhibit satisfying effectiveness 73.2 dB at thickness 11 μm, specific 31 150.1 dB·cm2·g-1. Benefiting from encapsulation, p-LMHA further impart hydrophobicity reliability harsh environments. Besides, devices integrate rapid-response behavior electro/photothermal and, meanwhile, function healthcare monitoring sensor. Therefore, believed that assembled independent offer facile solution for practical multimodular protection integration characteristics.

Language: Английский

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

Small, Journal Year: 2023, Volume and Issue: 19(41)

Published: June 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.

Language: Английский

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