A theory of electrical conductivity, dielectric constant, and electromagnetic interference shielding for lightweight graphene composite foams

2016 ◽  
Vol 120 (8) ◽  
pp. 085102 ◽  
Author(s):  
Xiaodong Xia ◽  
Yang Wang ◽  
Zheng Zhong ◽  
George J. Weng
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Electromagnetic Interference ◽  
Electromagnetic Interference Shielding ◽  
Graphene Composite ◽  
Composite Foams

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.

Electrical conductivity and electromagnetic interference shielding efficiency of carbon nanotube/cellulose composite paper

Carbon ◽  
2008 ◽  
Vol 46 (9) ◽  
pp. 1256-1258 ◽  
Author(s):  
Bunshi Fugetsu ◽  
Eiichi Sano ◽  
Masaki Sunada ◽  
Yuzuru Sambongi ◽  
Takao Shibuya ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Electromagnetic Interference ◽  
Electromagnetic Interference Shielding ◽  
Cellulose Composite ◽  
Composite Paper
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