MIL-88B (Fe) driven Fe/Fe3C encapsulated in high-crystalline carbon for high-efficient microwave absorption and electromagnetic interference shielding

2021 ◽  
Author(s):  
Xianfeng Yang ◽  
You Zhou ◽  
Hongna Xing ◽  
Hongpeng Wang ◽  
Wei Feng ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Magnetic Loss ◽  
Impedance Matching ◽  
Filling Ratio ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Dual Functional ◽  
High Efficient ◽  
Magnetic Dielectric

Abstract Dual-functional magnetic/dielectric Fe/Fe3C@C composites were fabricated by pyrolysis of MIL-88B (Fe) in Ar atmosphere, which was used for microwave absorption and electromagnetic interference (EMI) shielding. The Fe/Fe3C nanocrystals were completely encapsulated in crystalline carbon, which can improve the oxidation resistance capacity. Owing to the remarkable impedance matching and strong attenuation constants, Fe/Fe3C@C composites show an optimal RL value of -56.4 dB at 14.0 GHz and broad effective absorption bandwidth (RL ≤ -10 dB) of 4.8 GHz, when the filling ratio and absorber thickness are only 20 wt% and 1.9 mm, respectively. Resulted from the high conductivity of crystalline carbon, magnetic loss of Fe/Fe3C and core-shell structure, the Fe/Fe3C@C composites also show remarkable EMI shielding properties at X band, which are enhanced by increasing the filling ratio of Fe/Fe3C@C composites. When the filling ratio was 50 wt%, the EMI shielding efficiency can reach 35 dB. This work suggests that the magnetic/dielectric Fe/Fe3C@C is a good cadidate in microwave absorption and electromagnetic interference shielding.

scholarly journals A Healable and Mechanically Enhanced Composite with Segregated Conductive Network Structure for High-Efficient Electromagnetic Interference Shielding

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ting Wang ◽  
Wei-Wei Kong ◽  
Wan-Cheng Yu ◽  
Jie-Feng Gao ◽  
Kun Dai ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Diels Alder ◽  
Electrostatic Attraction ◽  
List Type ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Elongation At Break ◽  
High Efficient ◽  
Emi Se

Highlights The cationic waterborne polyurethanes microspheres with Diels-Alder bonds were synthesized for the first time. The electrostatic attraction not only endows the composite with segregated structure to gain high electromagnetic-interference shielding effectiveness, but also greatly enhances mechanical properties. Efficient healing property was realized under heating environment. Abstract It is still challenging for conductive polymer composite-based electromagnetic interference (EMI) shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness (EMI SE), especially undergoing external mechanical stimuli, such as scratches or large deformations. Herein, an electrostatic assembly strategy is adopted to design a healable and segregated carbon nanotube (CNT)/graphene oxide (GO)/polyurethane (PU) composite with excellent and reliable EMI SE, even bearing complex mechanical condition. The negatively charged CNT/GO hybrid is facilely adsorbed on the surface of positively charged PU microsphere to motivate formation of segregated conductive networks in CNT/GO/PU composite, establishing a high EMI SE of 52.7 dB at only 10 wt% CNT/GO loading. The Diels–Alder bonds in PU microsphere endow the CNT/GO/PU composite suffering three cutting/healing cycles with EMI SE retention up to 90%. Additionally, the electrostatic attraction between CNT/GO hybrid and PU microsphere helps to strong interfacial bonding in the composite, resulting in high tensile strength of 43.1 MPa and elongation at break of 626%. The healing efficiency of elongation at break achieves 95% when the composite endured three cutting/healing cycles. This work demonstrates a novel strategy for developing segregated EMI shielding composite with healable features and excellent mechanical performance and shows great potential in the durable and high precision electrical instruments.

Sustainable wood-based composites for microwave absorption and electromagnetic interference shielding

2020 ◽  
Vol 8 (46) ◽  
pp. 24267-24283 ◽  
Author(s):  
Ming Zhou ◽  
Weihua Gu ◽  
Gehuan Wang ◽  
Jing Zheng ◽  
Chunchuan Pei ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding

In this review, wood-based composites for efficient EMI shielding and MA are comprehensively introduced.

scholarly journals Graphene Infused Ecological Polymer Composites for Electromagnetic Interference Shielding and Heat Management Applications

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2856
Author(s):  
Klaudia Zeranska-Chudek ◽  
Anna Wróblewska ◽  
Sebastian Kowalczyk ◽  
Andrzej Plichta ◽  
Mariusz Zdrojek
Keyword(s):  
Polymer Composites ◽  
Electromagnetic Interference ◽  
Microwave Range ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Heat Management ◽  
Thick Sample ◽  
Graphene Nanoplatelet ◽  
Dual Functional ◽  
X Band

In the age of mobile electronics and increased aerospace interest, multifunctional materials such as the polymer composites reported here are interesting alternatives to conventional materials, offering reduced cost and size of an electrical device packaging. We report a detailed study of an ecological and dual-functional polymer composite for electromagnetic interference (EMI) shielding and heat management applications. We studied a series of polylactic acid/graphene nanoplatelet composites with six graphene nanoplatelet loadings, up to 15 wt%, and three different flake lateral sizes (0.2, 5 and 25 μm). The multifunctionality of the composites is realized via high EMI shielding efficiency exceeding 40 dB per 1 mm thick sample and thermal conductivity of 1.72 W/mK at 15 wt% nanofiller loading. The EMI shielding efficiency measurements were conducted in the microwave range between 0.2 to 12 GHz, consisting of the highly relevant X-band (8–12 GHz). Additionally, we investigate the influence of the nanofiller lateral size on the studied physical properties to optimize the studied functionalities per given nanofiller loading.

scholarly journals Robust, flexible, and high-performance electromagnetic interference shielding films with long-lasting service

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18476-18482
Author(s):  
Licui Wang ◽  
Zhaoxin Xie ◽  
Yanhu Zhan ◽  
Xuehui Hao ◽  
Yanyan Meng ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
High Performance ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding

It is of great significance for electromagnetic interference (EMI) shielding materials to fulfill long-lasting service requirements.

scholarly journals Interface Engineered Microcellular Magnetic Conductive Polyurethane Nanocomposite Foams for Electromagnetic Interference Shielding

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Guolong Sang ◽  
Pei Xu ◽  
Tong Yan ◽  
Vignesh Murugadoss ◽  
Nithesh Naik ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Magnetic Loss ◽  
Interfacial Polarization ◽  
Conductive Network ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Multiple Reflections ◽  
Conduction Loss ◽  
Composite Foams ◽  
Emi Se

Abstract Lightweight microcellular polyurethane (TPU)/carbon nanotubes (CNTs)/ nickel-coated CNTs (Ni@CNTs)/polymerizable ionic liquid copolymer (PIL) composite foams are prepared by non-solvent induced phase separation (NIPS). CNTs and Ni@CNTs modified by PIL provide more heterogeneous nucleation sites and inhibit the aggregation and combination of microcellular structure. Compared with TPU/CNTs, the TPU/CNTs/PIL and TPU/CNTs/Ni@CNTs/PIL composite foams with smaller microcellular structures have a high electromagnetic interference shielding effectiveness (EMI SE). The evaporate time regulates the microcellular structure, improves the conductive network of composite foams and reduces the microcellular size, which strengthens the multiple reflections of electromagnetic wave. The TPU/10CNTs/10Ni@CNTs/PIL foam exhibits slightly higher SE values (69.9 dB) compared with TPU/20CNTs/PIL foam (53.3 dB). The highest specific EMI SE of TPU/20CNTs/PIL and TPU/10CNTs/10Ni@CNTs/PIL reaches up to 187.2 and 211.5 dB/(g cm−3), respectively. The polarization losses caused by interfacial polarization between TPU substrates and conductive fillers, conduction loss caused by conductive network of fillers and magnetic loss caused by Ni@CNT synergistically attenuate the microwave energy.

Interface design of carbon filler/polymer composites for electromagnetic interference shielding

2021 ◽  
Author(s):  
Runxiao Chen ◽  
Rongrong Yu ◽  
Xiaoyuan Pei ◽  
Wei Wang ◽  
Diansen Li ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Electromagnetic Interference ◽  
Interface Design ◽  
Electrical Equipment ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Carbon Filler ◽  
Portable Electronics ◽  
Electromagnetic Pollution ◽  
Carbon Based

The extensive use of electrical equipment and portable electronics has aroused major concerns about electromagnetic pollution. Carbon-based polymer composites are widely used in the electromagnetic interference (EMI) shielding field, motivated...

Asymmetric Sandwich Structural Cellulose-based Film with Self-supported MXene and AgNW Layers for Flexible Electromagnetic Interference Shielding and Thermal Management

Nanoscale ◽  
2021 ◽  
Author(s):  
Bing Zhou ◽  
Qingtao Li ◽  
Penghui Xu ◽  
Yuezhan Feng ◽  
Jianmin Ma ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Thermal Management ◽  
Electromagnetic Interference ◽  
High Potential ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Conductive Films

Flexible cellulose-based conductive films reveal the high potential in electromagnetic interference (EMI) shielding and thermal management applications. However, the high contact electrical/thermal resistance in these films is still one of...

scholarly journals Direct Ink Writing of Highly Conductive MXene Frames for Tunable Electromagnetic Interference Shielding and Electromagnetic Wave-Induced Thermochromism

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinyu Wu ◽  
Tingxiang Tu ◽  
Yang Dai ◽  
Pingping Tang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Interference ◽  
High Performance ◽  
Normal Operation ◽  
List Type ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Direct Ink Writing ◽  
Aluminum Ions ◽  
Wave Induced

Highlights 3D printing of MXene frames with tunable electromagnetic interference shielding efficiency is demonstrated. Highly conductive MXene frames are reinforced by cross-linking with aluminum ions. Electromagnetic wave is visualized by electromagnetic-thermochromic MXene patterns. Abstract The highly integrated and miniaturized next-generation electronic products call for high-performance electromagnetic interference (EMI) shielding materials to assure the normal operation of their closely assembled components. However, the most current techniques are not adequate for the fabrication of shielding materials with programmable structure and controllable shielding efficiency. Herein, we demonstrate the direct ink writing of robust and highly conductive Ti3C2Tx MXene frames with customizable structures by using MXene/AlOOH inks for tunable EMI shielding and electromagnetic wave-induced thermochromism applications. The as-printed frames are reinforced by immersing in AlCl3/HCl solution to remove the electrically insulating AlOOH nanoparticles, as well as cross-link the MXene sheets and fuse the filament interfaces with aluminum ions. After freeze-drying, the resultant robust and porous MXene frames exhibit tunable EMI shielding efficiencies in the range of 25–80 dB with the highest electrical conductivity of 5323 S m−1. Furthermore, an electromagnetic wave-induced thermochromic MXene pattern is assembled by coating and curing with thermochromic polydimethylsiloxane on a printed MXene pattern, and its color can be changed from blue to red under the high-intensity electromagnetic irradiation. This work demonstrates a direct ink printing of customizable EMI frames and patterns for tuning EMI shielding efficiency and visualizing electromagnetic waves.

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