scholarly journals EMI Shielding using Composite Materials with Plasma Layers

10.5772/16553 ◽  
2011 ◽  
Author(s):  
Ziaja Jan ◽  
Jaroszewski Maciej
Keyword(s):  
Composite Materials ◽  
Emi Shielding

Wood fiber ferrite micro- and nano-composite materials for EMI-shielding

2013 ◽  
pp. 117-125
Author(s):  
K Dimitrov ◽  
T Döhler ◽  
M Herzog ◽  
S Schrader ◽  
S Nenkova
Keyword(s):  
Composite Materials ◽  
Wood Fiber ◽  
Emi Shielding ◽  
Nano Composite

Integration of Carbon Nanotubes Into a Fiberglass Reinforced Polymer Composite and its Effects on Electromagnetic Shielding and Mechanical Properties

2013 ◽  
Author(s):  
Mehran Tehrani ◽  
Ayoub Y. Boroujeni ◽  
Majid Manteghi ◽  
Zhixian Zhou ◽  
Marwan Al-Haik
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Composite Materials ◽  
Electromagnetic Interference ◽  
Hybrid Composites ◽  
Fiber Surface ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electrically Conductive ◽  
Coated Fabric

Electromagnetic (EM) waves, such as electronic noise and radio frequency interference can be regarded as an invisible electronic pollution which justifies a very active quest for effective electromagnetic interference (EMI) shielding materials. Highly conductive materials of adequate thickness are the primary solutions to shield against EMI. Equipment cases and basic structure of space aircraft and launch vehicles have traditionally been made of aluminum, steel and other electrically conductive metals. However, in recent years composite materials have been used for electronic equipment manufacturing because of their lightweight, high strength, and ease of fabrication. Despite these benefits, composite materials are not as electrically conductive as traditional metals, especially in terms of electrical grounding purposes and shielding. Therefore, extra effort must be taken to resolve these shortcomings. The present work demonstrates a study on developing hybrid composites based on fiberglass with surface grown carbon nanotubes (CNTs) for EMI applications. The choice of fiberglass is primarily because it naturally possesses poor electrical conductivity, hence growing CNTs over glass fiber surface can significantly improve the conductivity. The fabrics were sputter-coated with a thin layer of SiO2 thermal barrier prior to growing of CNTs. The CNTs were grown on the surface of woven fiberglass fabrics utilizing a relatively low temperature technique. Raw fiberglass fabric, SiO2 coated fabric, and SiO2 coated fabric which was subjected to the identical heat treatment as the samples with CNTs were also prepared. Two-layers composite specimens based on different surface treated fiberglass fabrics were fabricated and their EMI shielding effectiveness (SE) was measured. The EMI SE of the hybrid CNT-fiberglass composites was shown to be 5–10 times of the reference samples. However, the tensile mechanical properties of the composites based on the different above mentioned fibers revealed significant degradation due to the elevated CNT growth temperature and the addition of coating layer and CNTs. To further probe the structure of the hybrid composites and the inter-connectivity of the CNTs from one interface to another, sets of 20-layers composites based on different surface treated fabrics were also fabricated and characterized.

scholarly journals Sodium-Based Chitosan Polymer Embedded with Copper Selenide (CuSe) Flexible Film for High Electromagnetic Interference (EMI) Shielding Efficiency

2021 ◽  
Vol 7 (7) ◽  
pp. 102
Author(s):  
Nurul Huda Osman ◽  
Nurul Najiha Mazu ◽  
Josephine Ying Chyi Liew ◽  
Muhammad Mahyiddin Ramli ◽  
Andrei Victor Sandu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Fourier Transform ◽  
Composite Materials ◽  
Polymer Matrix ◽  
Electromagnetic Interference ◽  
Copper Selenide ◽  
Emi Shielding ◽  
Free Standing ◽  
Casting Technique ◽  
Flexible Film

Efficient shielding materials are extremely important to minimize the effect of electromagnetic interference. Currently, various composite materials are being investigated with different shielding efficiencies reported. In this paper, a flexible and free-standing sodium-based chitosan (CH/Na) polymer with copper selenide (CuSe) filler was prepared for electromagnetic shielding. The CH/Na/CuSe polymer matrix was prepared via the direct casting technique at different wt% of CuSe, varying from 2 to 20 wt%. The polymer matrix was then characterised by using Fourier transform infrared (FTIR) spectroscopy to confirm the interaction between the CH/Na and CuSe. The XRD results revealed that the CH/Na/CuSe polymer was successfully formed. Improvement in the electrical conductivity was confirmed by an impedance spectroscopy measurement. The highest electrical conduction recorded was at 3.69 × 10−5 S/cm for CH/Na/CuSe polymer matrix with 20 wt% CuSe. An increase in total electromagnetic interference (EMI) shielding efficiency (SET) of up to 20 dB (99% EM power shield) was achieved, and it can be increased up to 34 dB (99.9% EM power shield) with the thickness of the polymer increased.

Comparative Microstructures of Ion Milled and Electrochemically Thinned Composite Materials

1974 ◽  
Vol 32 ◽  
pp. 546-547
Author(s):  
R.R. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Composite Materials ◽  
Great Difficulty ◽  
Ion Milling ◽  
Transmission Electron ◽  
Ion Damage ◽  
Intermetallic Composite

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.

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