• Title/Summary/Keyword: Nanotubes

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Growth of Vertically Aligned Carbon Nanotubes on Co-Ni Alloy Metal (Co-Ni 합금위에서 수직방향으로 정렬된 탄소나노튜브의 성장)

  • Ryu, Jae-Eun;Lee, Cheol-Jin;Lee, Tae-Jae;Son, Gyeong-Hui;Sin, Dong-Hyeok
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.8
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    • pp.451-454
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    • 2000
  • We have grown vertically aligned carbon nanotubes in a large area of Co-Ni codeposited Si substrates by the thermal CVD usign $C_2H_2$ gas. Since the discovery of carbon nanotubes, growth of carbon nanotubes has been achieved by several methods such as laser vaporization, arc discharge, and pyrolysis. In particular, growth of vertically aligned nanotubes is important to flat panel display applications. Recently, vertically aligned carbon nanotubes have been grown on glass by PECVD. Aligned carbon nanotubes can be also grown on mesoporous silica and Fe patterned porous silicon using CVD. In this paper, we demonstrate that carbon nanotubes can be vertically aligned on catalyzed Si substrate when the domain density of catalytic particles reaches a certain value. We suggest that steric hindrance between nanotubes at an initial stage of the growth forces nanotubes to align vertically and each nonotubes are grown in bundle.

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Competitive Growth of Carbon Nanotubes versus Carbon Nanofibers

  • Kim, Sung-Hoon
    • Journal of the Korean Ceramic Society
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    • v.40 no.12
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    • pp.1150-1153
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    • 2003
  • Carbon nanofilaments were formed on silicon substrate using microwave plasma-enhanced chemical vapor deposition method. The structures of carbon nanofilaments were identified as carbon nanotubes or carbon nanofibers. The formation of bamboo-like carbon nanotubes was initiated by the application of the bias voltage during the plasma reaction. The growth kinetics of bamboo-like carbon nanotubes increased with increasing the bias voltage. The growth direction of bamboo-like carbon nanotubes was vertical to the substrate.

Microscopic Characterization of Cement Composites with Carbon Nanotubes (탄소나노튜브가 첨가된 시멘트복합체의 미시적특성분석)

  • Kim, Young-Min;Lee, Gun Cheol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.176-177
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    • 2019
  • As a result of the Rietveld analysis to determine the effect of carbon nanotubes on the hydration products of cement composites, the quantitative difference of hydration products according to the addition rate of carbon nanotubes was not significant. Ettringite, an early hydration product, was measured to be slightly higher than the planes with carbon nanotubes over all ages. Therefore, it seems that carbon nanotubes have no effect on the hydration production in cement paste.

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SWNTs growth using nano-catalyst-embedded particles

  • Lee, Su-Hong;Han, Jae-Hee;Lee, Tae-Young;Park, Yong-Choon;Berdinsky, A.S.;Kwan, Young-Uk;Yoo, Ji-Beom;Park, Chong-Yun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.465-467
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    • 2004
  • We presented a systematic investigation on the growth of CNTs including SWNTs on nano-catalyst-embedded particles by PECVD. For CNTs growth, the mixture of $C_2H_2$ and $NH_3$ was used. The total pressure and temperature were kept at 3.25 Torr and 650 $^{\circ}C$, respectively. Finally, we measured the field emission property from CNTs grown from nano-catalyst embedded zeolite particles in vacuum chamber (<$10^{-7}$ Torr).

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Separation of Single-Walled Carbon Nanotubes by Length and Diameter (단일벽 탄소 나노튜브의 길이와 지름에 따른 분류)

  • Oh Young-Seok;Lee Dock-Jin;Chang Yyun-Seok;Choi Jae-Boong;Kim Young-Jin;Baik Seung-Hyun
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.3 s.180
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    • pp.171-178
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    • 2006
  • The sonication mettled is widely used with surfactants to suspend individual single-walled carbon nanotubes in solution, and it is well known that sonication-induced tube cutting occurs. Recently, it is found out that ultrasonicated nanotubes yield simultaneous separation by tube length and diameter. Nanotubes that have been cut shortest possess the greatest enrichments of large-diameter species. In this study, single-walled carbon nanotubes are cut using a ball milling method. Similar fracture behavior is observed fur the ball milled nanotubes: i.e., large diameter tubes are cut shorter. The ability to separate carbon nanotubes by diameter and length will contribute to tile development of nanotube-based applications.

Effect of the Applied Bias Voltage on the Formation of Vertically Well-Aligned Carbon Nanotubes (탄소 나노 튜브의 수직 배향에 대한 바이어스 인가 전압의 효과)

  • Kim, Sung-Hoon
    • Korean Journal of Materials Research
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    • v.13 no.7
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    • pp.415-419
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    • 2003
  • Carbon nanotubes were formed on silicon substrate using microwave plasma-enhanced chemical vapor deposition method. The possibility of carbon nanotubes formation was related to the thickness of nickel catalyst. The growth behavior of carbon nanotubes under the identical thickness of nickel catalyst was strongly dependent on the magnitude of the applied bias voltage. High negative bias voltage (-400 V) gave the vertically well-aligned carbon nanotubes. The vertically well-aligned carbon nanotubes have the multi-walled structure with nickel catalyst at the end position of the nanotubes.