Facile heteroatom doping of biomass-derived carbon aerogels with hierarchically porous architecture and hybrid conductive network: Towards high electromagnetic interference shielding effectiveness and high absorption coefficient

2021 ◽  
pp. 109175
Author(s):  
Meng-Lin Wang ◽  
Sheng Zhang ◽  
Zi-Han Zhou ◽  
Jin-Long Zhu ◽  
Jie-Feng Gao ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Carbon Aerogels ◽  
Conductive Network ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Heteroatom Doping ◽  
Porous Architecture ◽  
High Absorption Coefficient ◽  
Electromagnetic Interference Shielding Effectiveness ◽  
High Absorption

EMI Shielding Effectiveness of CNTs Composites

2013 ◽  
Vol 331 ◽  
pp. 439-442 ◽  
Author(s):  
Ping Li ◽  
Aik Seng Low ◽  
Yue Yan Shan ◽  
Guat Choon Ong ◽  
Xi Jiang Yin
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Interference ◽  
Conductive Network ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Frequency Range ◽  
Electromagnetic Interference Shielding ◽  
Emi Shielding Effectiveness ◽  
Electromagnetic Interference Shielding Effectiveness ◽  
5 Ghz

A carbon nanotubes (CNTs) composite and its electromagnetic interference shielding effectiveness (SE) were investigated. Its absorptance, reflectance and shielding effectiveness (SE) were analysed. The CNTs composite has a shielding effectiveness (SE) of more than 25 dB (>99.68%) in frequency range from 30 MHz to 5 GHz. The testing results also demonstrate that the shielding mechanism of the CNTs composite is mainly EMI absorption of electromagnitic radiation. The high SE of the CNTs composite in the study is attributed to a high aspect ratio (>3000) and good conductive network of CNTs within the composite.

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.

Electromagnetic interference shielding effectiveness of polypyrrole-silver nanocomposite films on silane-modified flexible sheet

2021 ◽  
pp. 095400832110645
Author(s):  
Karim Benzaoui ◽  
Achour Ales ◽  
Ahmed Mekki ◽  
Abdelhalim Zaoui ◽  
Boudjemaa Bouaouina ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Electromagnetic Interference ◽  
Nanocomposite Films ◽  
Electrical Characteristics ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Silver Nanocomposite ◽  
Electromagnetic Interference Shielding Effectiveness ◽  
Emi Se

The conventional electromagnetic interference (EMI) shielding materials are being gradually replaced by a new generation of supported conducting polymer composites (CPC) films due to their many advantages. This work presents a contribution on the effects of silane surface–modified flexible polypyrrole-silver nanocomposite films on the electromagnetic interference shielding effectiveness (EMI-SE). Thus, the UV-polymerization was used to in-situ deposit the PPy-Ag on the biaxial oriented polyethylene terephthalate (BOPET) flexible substrates whose surfaces were treated by 3-aminopropyltrimethoxysilane (APTMS). X-ray Photoelectron Spectroscopy (XPS) analyzes confirmed the APTMS grafting procedure. Structural, morphological, thermal, and electrical characteristics of the prepared films were correlated to the effect of substrate surface treatment. Thereafter, EMI-SE measurements of the elaborated films were carried out as per ASTM D4935 standard for a wide frequency band extending from 50 MHz to 18 GHz. The obtained results confirmed that the APTMS-treated BOPET film exhibit higher EMI shielding performance and better electrical characteristics compared to the untreated film. In fact, a 32% enhancement of EMI-SE was noted for the treated films compared to the untreated ones. Overall, these results put forward the role played by the surface treatment in strengthening the position of flexible PPy-Ag supported films as high-performance materials in electronic devices and electromagnetic interference shielding applications.

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