• Title/Summary/Keyword: conductive carbon

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Electromagnetic Interference shielding effectiveness of carbon black / Glass fiber woven roving and Carbon fiber unidirectional fabric reinforced composite (카본블랙/섬유강화 복합재료의 전자파 차폐효과)

  • Kim J.S.;Han G.Y.;Ahn D.G.;Lee S.H.;Kim M.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1322-1325
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    • 2005
  • The main objectives of this research work are to develop conductive glass fiber woven roving and carbon fiber unidirectional fabric composite materials and to determine their electromagnetic shielding effectiveness(EMSE). Epoxy is the matrix phase and glass, carbon fiber are the reinforcement phase of the composite material. Carbon black are incorporated as conductive fillers to provide the electromagnetic shielding properties of the composite material. The amount of carbon black in the composite material is varied by changing the carbon black composition, woven roving and unidirectional (fabric) structure. The EMSE of various fabric composites is measured in the frequency range from 300MHz to 800MHz. The variations of EMSE of woven roving and unidirectional composites with fabric structure, metal powder composite are described. Suitability of conductive fabric composites for electromagnetic shielding applications is also discussed.

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Analysis of conductive mechanism on self-diagnosis FRP (자기진단 FRP의 도전기구 해석)

  • 임현주;이학용;신순기;이준희
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.04a
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    • pp.27-30
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    • 2003
  • In order to apply fracture detection we fabricated the CP-FRP using carbon-powder and analyzed conductive mechanism of it. The composites showed lower initial resistance as the carbon powder and amount of glass fiber(TEX) was used much more. When those are compared with each other that before and after bending test, the more cracks observed in matrix after bending test. We become to know that the conductivity of the composites depends on percolation structure of carbon powder.

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Temperature Dependence on Structural, Tribological, and Electrical Properties of Sputtered Conductive Carbon Thin Films

  • Park, Yong-Seob;Hong, Byung-You;Cho, Sang-Jin;Boo, Jin-Hyo
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.939-942
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    • 2011
  • Conductive carbon films were prepared at room temperature by unbalanced magnetron sputtering (UBMS) on silicon substrates using argon (Ar) gas, and the effects of post-annealing temperature on the structural, tribological, and electrical properties of carbon films were investigated. Films were annealed at temperatures ranging from $400^{\circ}C$ to $700^{\circ}C$ in increments of $100^{\circ}C$ using a rapid thermal annealing method by vacuum furnace in vacuum ambient. The increase of annealing temperature contributed to the increase of the ordering and formation of aromatic rings in the carbon film. Consequently, with increasing annealing temperature the tribological properties of sputtered carbon films are deteriorated while the resistivity of carbon films significantly decreased from $4.5{\times}10^{-3}$ to $1.0{\times}10^{-6}\;{\Omega}-cm$ and carrier concentration as well as mobility increased, respectively. This behavior can be explained by the increase of sp2 bonding fraction and ordering $sp^2$ clusters in the carbon networks caused by increasing annealing temperature.

An Experimental Study on the Exothermic Properties of Cement Mortar Containing Conductive Materials (전도성 재료를 혼입한 모르타르의 발열특성에 관한 실험적 연구)

  • Song, Dong-Geun;Hong, Chul-Ho;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.131-132
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    • 2014
  • In this study, an experiment was carried out using graphite, conductive nickel powder, copper bar, carbon fiber for evaluate the exothermic properties and heating reproducibility of the cement mortar containing conductive material. As a result, the conductive materials that interfere with heating reproducibility are present, and the optimal conductive materials exist in each input voltage.

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Modification of C/C Composite Bipolar Plate by Addition of Electro-Conductive Carbon Black

  • Ryu, Seung-Kon;Hwang, Taek-Sung;Lee, Seung-Goo;Lee, Sun-A;Kim, Chang-Soo
    • Carbon letters
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    • v.2 no.3_4
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    • pp.165-169
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    • 2001
  • Modification of C/C composite bipolar plate for improving electrical conductivity was carried out by addition of electroconductive carbon black (EC-CB). Carbon black was carefully mixed to methanol-containing phenolic resin, impregnated into 2D-carbon fabrics, hot pressed and then carbonized to obtain composite plate. Inclusion of electro-conductive carbon black enhanced the electrical conductivity of the C/C composites by increasing the conduction path. Addition of 10 vol% carbon black increased the electrical conductivity from 5.5/${\Omega}cm$ to 32/${\Omega}cm$ and reduced the crack formation by filling effect, resulting in the increase of flexural properties of composite plate. However, at carbon black content over 10 vol%, flexural properties decreased by delaminating role of excess carbon black at the interface in C/C composites.

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Carbon Nanotube Incoporated Conductive Pastes (탄소나노튜브를 이용한 전도성 페이스트)

  • Oh, Young-Seok;Suh, Dae-Woo;Kim, Young-Jin;Choi, Jae-Boong;Baik, Seung-Hyun
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1908-1912
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    • 2008
  • Conductive polymers, prepared by mixing electrically conductive fillers with a suitable polymeric formulation, are widely used in applications such as interconnecting materials for high density electronic packaging. However, resins of conductive pastes used as binders and vehicles are generally nonconductive, so that they may prevent the electrical contact between conductive fillers and reduce electron transmission. In this study, we improved conductivity of silver paste by the incorporation of cabon nanotubes. It is important to achieve homogeneous dispersion of CNTs to act as reinforcements efficiently in matrix. We carried out acid treatment on nanotubes for their homogeneous dispersion in silver/conducting polymer matrix. The dispersion states of nanotubes were characterized by raman spectra and filed emission scanning electron microscope. The electrical resistivity of CNTs incorporated silver paste was also measured by 4-point probe method.

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Characterization of Transparent Electrodes using Carbon Nanotubes Coated by Conductive Polymers (전도성 고분자가 코팅된 탄소 나노튜브 투명전극의 특성 분석)

  • Kim, Bu-Jong;Han, Sang-Hoon;Park, Jin-Seok
    • Journal of the Semiconductor & Display Technology
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    • v.13 no.1
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    • pp.19-25
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    • 2014
  • This study demonstrates transparent electrodes with characteristics desirable for touch screen panels using carbon nanotubes (CNTs). This has been accomplished by depositing CNTs on glass substrates via spray coating and then depositing thin conductive polymer films on the CNTs via spin coating. For all of the samples, such as CNTs, conductive polymers, and polymer-coated CNTs, the surface morphologies, sheet resistances, visible transmittances, chromatic properties are characterized as functions of their preparation conditions, such as the spray times for CNTs and the spin speeds for conductive polymers. The experimental results confirm that only the polymer-coated CNTs can satisfy all of the requirements that are required for electrodes of touch screen panels, such as the sheet resistance lower than $100{\Omega}/sq$, the visible transmittance higher than 80 %, and the yellowness smaller than 1.

Electromagnetic Interference Shielding Effectiveness of Hybrid Conductive Fabrics (하이브리드 전도성 직조섬유의 전자파 차폐효과)

  • Han, Gil-Young;Kim, Ki-Yeol;Yun, Tae-Soon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.2
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    • pp.81-86
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    • 2015
  • This study investigated electromagnetic interference (EMI) shielding effectiveness (SE) of hybrid conductive fabrics. The coaxial transmission line method was used to measure the EMI Shielding effectiveness of the conductive fabrics. We designed and constructed a measuring system, consisting of a network analyzer and a device that serves as a sample holder and at the same time as a transmission medium of incident electromagnetic waves. The measurements of SE were carried out in a frequency range from 100 MHz to 2 GHz. The results of the EMI shielding experiments showed that the maximum electromagnetic shielding effectiveness (EMSE) values of sandwich type C/A/C (carbon fiber sheet/aluminum foil tape/carbon fiber sheet) and C/Ni/C (carbon fiber sheet/magnetic shielding foil/carbon fiber sheet) samples were 55 dB and 113 dB, respectively, at a frequency of 1.9 GHz.

Effects of Sintering Temperature on the Electrical Conductivities of the Y2O3-Carbon Composites (Y2O3-카본 복합체의 전기전도성에 미치는 소결온도의 영향)

  • Choi, Kwan-Young;Oh, Yoon-Suk;Kim, Sung-Won;Kim, Hyung-Sun;Park, Chong-Hun;Lee, Sung-Min
    • Journal of the Korean Ceramic Society
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    • v.49 no.2
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    • pp.173-178
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    • 2012
  • The $Y_2O_3$ ceramics have been widely used as plasma resistant materials in the semiconductor industry. In this study, composites made of plasma resistant $Y_2O_3$ and electrically conductive carbon have been produced. The electrical properties of this composite were measured with respect to the size, volume fraction of the conductive carbon phase, and sintering temperature. When micro-sized carbon was used, the composites were insulating up to 5 wt% addition of the carbon. However, when nano-sized carbon of around 60 ~100 nm was used, the composites became conductive over threshold volume fraction of carbon, which increased with increasing sintering temperature. This behavior of electrical conductivity of the composites was discussed in terms of the percolation theory. The percolation threshold of the conductivity seemed to be affected by the grain growth and coalescences of dispersed conductive carbon phases with grain growth of matrix $Y_2O_3$.

Improvement of Nitrogen Oxide Removal of Concrete Sidewalk Block Using by Conductive Photocatalyst (전도성 광촉매를 이용한 콘크리트 블록의 대기중 질소산화물 저감에 관한 연구)

  • Geun-Guk Bae;In-Sook Cho;Yong-Sik Ahn
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.4
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    • pp.493-500
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    • 2023
  • The use of TiO2 photocatalyst in the production of concrete blocks for the purpose of nitrogen oxide reduction is an issue of controversy due to the conflicting evidence on its effectiveness. Efforts have been made to reduce the level of nitrogen oxides in the environment by using of titanium dioxide (TiO2). This study examined the effect of incorporating activated carbon into concrete blocks on the reduction of nitrogen oxides released into the atmosphere and the durability of the blocks. The efficiency of photocatalyst was enhanced through the addition of a surrounding conductive substance. The addition of activated carbon resulted in a significant increase in the electrical conductivity of photocatalytic blocks and improved durability. The cement mixture using 5 % TiO2 and 15 % activated carbon exhibited the optimal mixing ratio for the purpose of nitrogen oxide removal. The effect of the addition of conductive carbon to the photocatalytic blocks was discussed with the results of conductivity, flexural and comprssive strength and nitrogen oxide removal test. The relationship between the addition of conductive carbon to the photocatalytic blocks and its resulting effects have been studied by several tests, including conductivity, flexural and compressive strength, and nitrogen oxide removal.