Realization of electromagnetic shielding performance for polyimide-matrix composite by self-metallization

2021 ◽  
pp. 002199832110316
Author(s):  
Jiayang Zhang ◽  
Hongjiang Ni ◽  
Ming Gong ◽  
Jun Li ◽  
Daijun Zhang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Matrix Composite ◽  
Electromagnetic Interference ◽  
Interfacial Strength ◽  
Amic Acid ◽  
Thermal Reduction ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Heat Condition ◽  
Electromagnetic Interference Shielding Effectiveness

Electromagnetic shielding performance has been achieved for a polyimide (PI)-matrix composite by the strategy of self-metallization of its thermosetting PI matrix. Self-metallization of the thermosetting PI was realized by silver ion/poly(amic acid) (PAA) precursor ion exchange and thermal reduction. The factors influencing the self-metallization were investigated. The electrical conductivity and integrity for the surface of the PI were achieved by optimization of ion exchange/thermal reduction parameters. The fabricated PI-matrix composite exhibits a maximum electromagnetic interference shielding effectiveness value of 81 dB. Importantly, the electromagnetic shielding performance can be maintained even after heat condition of 300°C. Meanwhile, the surface-metallized PI composite exhibits mechanical property equivalent to the pristine composite, and an Ag/matrix interfacial strength higher than 19.6 MPa. Besides, self-metallization mechanism of the thermosetting PI was investigated.

Electromagnetic Shielding Effectiveness of Cement-Matrix Composite Containing Nickel Fiber

2010 ◽  
Vol 177 ◽  
pp. 570-573 ◽  
Author(s):  
Liu Jun Luo ◽  
Guo Xuan Xiong ◽  
Shu Fang Zheng ◽  
Min Deng
Keyword(s):  
Matrix Composite ◽  
Electromagnetic Interference ◽  
Coaxial Cable ◽  
Cement Matrix ◽  
Dispersion Property ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Electromagnetic Interference Shielding Effectiveness ◽  
Electromagnetic Shielding Effectiveness ◽  
Better Than

The cement-matrix composite with the function of building structure and electromagnetic interference shielding was prepared by filling nickel fiber into cement. The dispersion of nickel fiber in cement-matrix composite and the shielding effectiveness of composite containing various volume fractions of nickel fiber were investgated in this paper. The electromagnetic interference shielding effectiveness in the frequency range of 0.1 MHz to 1.5 GHz and the conductivity of composite were measured by coaxial cable method and two-probe method, respectively. The dispersion of nickel fiber in cement was characterized by EPMA. The results indicated that the dispersion property of nickel fiber by sodium hexametaphosphatecan was better than sodium carboxymethylcellulose. The optimum contents of nickel fiber in composite was 5 vol.%, the maximum shielding effectiveness was 45.7 dB in 140 MHz and the minimum shielding effectiveness was 36 dB in 1240 MHz. The shielding effectiveness of composite with 7 vol.% nickel fiber was lower than that with 5 vol.% nickel fiber due to the tendency of nickel fiber cling to each other.

Investigation of Electromagnetic Interference Shielding Effectiveness of Cement-Based Composites Filled with Carbon Materials

2010 ◽  
Vol 168-170 ◽  
pp. 1021-1024
Author(s):  
Guo Xuan Xiong ◽  
Zhi Bin Zhang ◽  
Min Deng ◽  
Yu Fen Zhou
Keyword(s):  
Carbon Fiber ◽  
Carbon Black ◽  
Electromagnetic Interference ◽  
Carbon Materials ◽  
Shielding Effectiveness ◽  
Nano Carbon ◽  
Electromagnetic Interference Shielding Effectiveness ◽  
Carbon Nano Tube ◽  
Relationship Of ◽  
The Relationship

The cement-based composite shielding materials filled with carbon materials such as ordinary carbon materials (graphite, coke and carbon black), carbon fiber and nano-carbon materials (carbon nano-tube and nano-carbon black) were prepared. The relationship of conductivity and shielding effectiveness in a frequency range of 100 KHz~1.5 GHz was studied. The electric properties of cement-based composites filled with carbon fiber is better than other carbon materials. With the contents of carbon fiber of 5.vol%, the average shielding effectiveness is about 37 dB and the maximum shielding effectiveness reaches 40 dB.

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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