• Title/Summary/Keyword: Functional materials

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Multi-walled Carbon Nanotube-Reinforced Hydroxyapatite Coating on Ti Substrates by Aerosol Deposition (에어로졸 증착법에 의해 티타늄 기판위에 제조된 다중벽 탄소나노튜브 강화 수산화아파타이트 코팅층)

  • Hahn, Byung-Dong;Park, Dong-Soo;Ryu, Jung-Ho;Choi, Jong-Jin;Yoon, Woon-Ha;Lee, Byung-Kuk;Kim, Hyoun-Ee
    • Journal of the Korean Ceramic Society
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    • v.45 no.10
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    • pp.610-617
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    • 2008
  • Multi-walled carbon nanotube(CNT) reinforced hydroxyapatite composite coating with a thickness of $5{\mu}m$ has been successfully deposited on Ti substrate using aerosol deposition(AD). The coating had a dense microstructure with no cracks or pores, showing good adhesion with the Ti substrate. Microstructural observation using field-emission scanning electron microscopy(FE-SEM) and transmission electron microscopy(TEM) showed that CNTs with original tubular morphology were found in the hydroxyapatite-CNT(HA-CNT) composite coating. Measurements of hardness and elastic modulus for the coating were performed by nanoindentation tests, indicating that the mechanical properties of the coating were remarkably improved by the addition of CNT to HA coating. Therefore, HA-CNT composite coating produced by AD is expected to be potentially applied to the coating for high load bearing implants.

Fabrication and Performance of Superconducting magnet (고온초전도 자석 제조 및 특성)

  • Hong, Gye-Won;Lee, Ho-Jin;Kim, Weon-Ju;Kim, Ki-Baik;Kwon, Sun-Chil
    • 한국초전도학회:학술대회논문집
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    • v.9
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    • pp.405-408
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    • 1999
  • A prototype of solenoidal superconducting magnet using Bi-2223/Ag multi-filamentary tapes was fabricated and tested to investigate its performance. The Bi-2223/Ag tapes were prepared by powder-in-tube method. The dimensions of magnet, which was stacked with 9 double pancakes, were 90 mm in height, 74 mm in outer diameter and 40 mm in clear core. The axial maximum magnet field at the center of the solenoidal magnet was about 0.12 T, and the critical current of coil conductor was about 9 A at 77.3 K.

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In-situ rf treatment of multiwall carbon nanotube with various post techniques for enhanced field emission

  • Ahn, Kyoung-Soo;Kim, Jun-Sik;Kim, Ji-Hoon;Kim, Chae-Ok;Hong, Jin-Pyo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.859-862
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    • 2003
  • Well-aligned multiwall carbon nanotubes (MWCNTs) were prepared at low temperature of 400 $^{\circ}C$ by utilizing a radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWCNTs were treated by an external rf plasma source and an ultra-violet laser in order to modify structural defect of carbon nanotube and to ablate possible contamination on carbon nanotube surface. Structural properties of carbon nanotubes were investigated by using a scanning electron microscopy (SEM), Raman spectroscopy, Fourier transformer Infrared spectroscopy (FTIR) and transmission electron microscope (TEM). In addition, the emission properties of the MWNTs were measured for the application of field emission display (FED) in near future. Various post treatments were found to improve the field emission property of carbon nanotubes.

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