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Enhancement of the Electromagnetic Wave Shielding Effectiveness by Geometry-Controlled Carbon Coils

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http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53359#.VMBgwizQrzE

Author(s)   
Gi-Hwan Kang1, Sung-Hoon Kim1*, Saehyun Kim2

Affiliation(s)
1Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736, Republic of Korea.
2Onnuri International Christian Academy, Yangsan, Kyungnam, 626-813, Republic of Korea.

ABSTRACT
Carbon microcoils were deposited onto Al2O3 substrates using C2H2/H2 as source gases and SF6 as an incorporated additive gas in a thermal chemical vapor deposition system. At as-grown state, the carbon coils (d-CCs) show the diverse geometry. The geometry-controlled carbon microcoils (g-CMCs) could be obtained by manipulating the injection time of SF6 in C2H2 source gas. The d-CCs with polyurethane (PU) composite (d-CC@PU) and the g-CMCs with PU composite (g-CMC@PU) were obtained by dispersing d-CCs and g-CMCs in PU, respectively. The electromagnetic wave shielding properties of d-CC@PU and g-CMC@PU composites were investigated in the frequency range of 0.25 - 4.0 GHz. The shielding effectiveness (SE) of d-CC@PU and g-CMC@PU composites were measured and discussed according to the weight percent of d-CCs and g-CMCs in the composites with the thickness of the composites layers. On the whole frequency range in this work, the SE of g-CMC@PU composites was higher than those of d-CC@PU composites, irrespective of the weight percent of carbon coils in the composites and the layer thickness. Furthermore, we confirmed that the absorption mechanism, instead of the reflection mechanism, seemed to play the critical role to shield the EMI for not only the g-CMC@PU composites but also the d-CC@PU composites.

KEYWORDS
Carbon Coils, Electromagnetic Wave Interference, Shielding Effectiveness, Absorption Mechanism

Cite this paper
Kang, G. , Kim, S. and Kim, S. (2015) Enhancement of the Electromagnetic Wave Shielding Effectiveness by Geometry-Controlled Carbon Coils. Journal of Materials Science and Chemical Engineering, 3, 37-44. doi: 10.4236/msce.2015.31006.

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