• 제목/요약/키워드: Multi-Wall Carbon Nanotube

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Carbon nanotube based transparent electrodes for flexible displays using liquid crystal devices

  • Shin, Jun-Ho;Lee, H.C.;Lee, J.H.;Park, S.M.;Alegaonkar, P.S.;Yoo, J.B.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.897-899
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    • 2007
  • Transparent electrodes for a flexible display based on the liquid crystal (LC) were formed by carbon nanotubes (CNTs) on polyethylene terephthalate (PET) substrates. The thin multi wall carbon nanotubes (t-MWNTs) networks for electrodes were obtained by filtration- transfer method from welldispersed CNTs solution.

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탄소나노튜브 및 그래핀 나노유체 사용시 장기운전에 따른 열전달성능 변화에 대한 연구 (Study on Heat Transfer Performance Change According to Long-term Operation Using Carbon Nanotube and Graphene Nanofluid)

  • 김영훈;김남진
    • 한국태양에너지학회 논문집
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    • 제37권1호
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    • pp.15-23
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    • 2017
  • Critical heat flux refers to the sudden decrease in boiling heat transfer coefficient between a heated surface and fluid, which occurs when the phase of the fluid near the heated surface changes from liquid to vapor. For this reason, critical heat flux is an important factor for determining the maximum limit and safety of a boiling heat transfer. Recently, it is reported that the nanofluid is used as a working fluid for the critical heat flux enhancement. However, it could be occurred nano-flouling phenomena on the heat transfer surface due to nanoparticles deposition, when the nanofluid is applied in a heat transfer system. In this study, we experimentally carried out the effects of the nano-fouling phenomena in oxidized multi-wall carbon nanotube and oxidized graphene nanofluid systems. It was found that the boiling heat flux decreased by hourly 0.04 and $0.03kW/m^2$, also the boiling heat transfer coefficient decreased by hourly 11.56 and $10.72W/m^2{\cdot}K$, respectively, in the thermal fluid system using oxidized multi-wall carbon nanotube or oxidized graphene nanofluid.

Electrochemical Determination of Artemisinin Using a Multi-wall Carbon Nanotube Film-modified Electrode

  • Yang, Xiaofeng;Gan, Tian;Zheng, Xiaojiang;Zhu, Dazhai;Wu, Kangbing
    • Bulletin of the Korean Chemical Society
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    • 제29권7호
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    • pp.1386-1390
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    • 2008
  • Artemisinin, the effective ingredient of Chinese herb Artemisia annua L (Qinghao in Chinese), has been proved to be effective to antimalarial. Herein, a reliable, sensitive and convenient electrochemical method was developed for the determination of artemisinin utilizing the excellent properties of multi-wall carbon nanotube (MWNT). The electrochemical behavior of artemisinin was investigated. It is found that the reduction peak current of artemisinin remarkably increases and the peak potential shifts positively by 240 mV at the MWNT film-modified electrode. These phenomena indicate that the MWNT film exhibits efficient catalytic activity to the electrochemical reduction of artemisinin. The effects of pH value, amount of MWNT, scan rate and accumulation time were examined. The limit of detection (S/N = 3) is as low as 10 $\mu$ g $L^{-1}$. Finally, this newly developed method was used to determine the content of artemisinin in Artemisia annua L.

플라즈마 기상 화학 증착법을 이용한 탄소나노튜브의 선택적 수직성장 기술 (Selective Growth of Freestanding Carbon Nanotubes Using Plasma-Enhanced Chemical Vapor Deposition)

  • 방윤영;장원석
    • 한국정밀공학회지
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    • 제24권6호
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    • pp.113-120
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    • 2007
  • Chemical vapor deposition (CVD) is one of the various synthesis methods that have been employed for carbon nanotube (CNT) growth. In particular, Ren et al reported that large areas of vertically aligned multi-wall carbon nanotubes could be grown using a direct current (dc) PECVD system. The synthesis of CNT requires a metal catalyst layer, etchant gas, and a carbon source. In this work, the substrates consists of Si wafers with Ni-deposited film. Ammonia $NH_3$) and acetylene ($C_2H_2$) were used as the etchant gases and carbon source, respectively. Pretreated conditions had an influence on vertical growth and density of CNTs. And patterned growth of CNTs could be achieved by lithographical defining the Ni catalyst prior to growth. The length of single CNT was increased as niclel dot size increased, but the growth rate was reduced when nickel dot size was more than 200 nm due to the synthesis of several CNTs on single Ni dot. The morphology of the carbon nanotubes by TEM showed that vertical CNTs were multi-wall and tip-type growth mode structure in which a Ni cap was at the end of the CNT.

활성탄, 합성 층상이중층 수산화물, 카본나노튜브를 이용한 수용액상의 카드뮴의 제거와 흡착제 독성 연구 (Evaluating Cadmium Ion Removal in Aqueous Solutions and Cytotoxicity Evaluation of Carbon, Synthesized Layered Double Hydroxide, and Multi-wall Carbon Nanotube)

  • 김태경;박복성;정용준
    • 한국물환경학회지
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    • 제33권2호
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    • pp.211-218
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    • 2017
  • This experiment was carried out with the purpose of testing cadmium adsorption abilities of multi wall carbon nanotube (MWCNT), activated carbon, and synthesized layered double hydroxide (LDH). In the acidic condition, only MWCNT was effective for removing cadmium ion in the aqueous phase while other adsorbents rarely removed it. The MWCNT and cadmium ion adsorption reactions followed pseudo-first order kinetic. When the initial pH value was neutral (pH = 7), cadmium ion was rapidly removed by MWCNT and activated carbon in 4 hr (100% and 99.2%, respectively). Increasing adsorbent dosages affects the pH evolution and cadmium ion removal (0 to 99%). Cytotoxicity test showed that both MWCNT and LDH has low cytotoxic effects on three kind of human cells (A549, HS-294t, and HT-29).

임베디드 시스템을 위한 탄소나노튜브 오실레이터의 특성 해석 (Characteristics of Carbon Nanotube Oscillator for Embedded System)

  • 이준하
    • 한국산학기술학회논문지
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    • 제9권5호
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    • pp.1150-1153
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    • 2008
  • 본 논문은 탄소 나노 튜브 (CNT)로 형성된 다중벽 탄소 나노튜브의 진동 특성을 분자 역학적 시뮬레이션 방법에 의해 해석하였다. 이로부터 이중벽 탄소 나노튜브에 비하여 다중벽 탄소 나노튜브의 경우 진동 주파수 분할이 발생됨을 분석하였다. 또한 세개의 주파수 발생자로써의 4차 벽, 5차 벽, 6차 함수 벽으로 된 오실레이터와 직경으로부터 독립적인 적합성 제안을 위해 지속적인 세 개의 정점이 나타나는 것으로 분석되었다.

Effects of Environmental Gases on Emission Current in Carbon Nanotube

  • Kim, T.S.;Ahn, B.K.;Kim, D.H.;Shin, H.Y.;Seong, M.S.;Cho, Y.R.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.700-702
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    • 2004
  • The dependence of environmental gases such as Ar, $O_2$ on the emission current from carbon nanotube emitters was examined in this study. Based on our experiments, the current density is decreased in single-wall carbon nanotubes (SWNTs), but is increased in multi-wall carbon nanotubes (MWNTs) as the vacuum level decreases from $10^{-7}$ Torr to $10^{-4}$ Torr by the inflow purging gases. The current density subsequently recovered as the vacuum level increased to $10^{-7}$ Torr when gas inflow stopped. From those results, we conclude that the MWNTs have completely different degradation characteristics in comparison to SWNTs excluding the effect of binder materials.

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C60@MWCNT: Room Temperature Encapsulation of C60 into Multiwall Carbon Nanotubes

  • Gupta, Vinay;Bahl, Om P.;Mathur, Rakesh B.
    • Carbon letters
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    • 제11권1호
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    • pp.9-12
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    • 2010
  • The synthesis of $C_{60}$@MWCNT was carried out at room temperature (${\sim}25^{\circ}C$) from arc-discharge prepared Multi-wall carbon nanotubes (MWCNTs). They were oxidized and acid treated for tube opening. Then $C_{60}$ molecules were encapsulated into MWCNTs by wetting them with $C_{60}$-toluene solution for several minutes followed by ultrasonification. $C_{60}$@MWCNT was cleaned by pure toluene to remove any excess $C_{60}$. $C_{60}$@MWCNT was characterized by electron microscopy, which showed large scale filling of $C_{60}$ into MWCNTs. It was observed that the mechanism of insertion of $C_{60}$ into MWCNTs may be due to the capillary suction at the opening ends of MWCNTs.

탄소 나노튜브를 활용한 나노 구조물에 대한 시뮬레이션 연구 (A Study of Nanostructure by Carbon Nanotube Simulation)

  • 이준하;이흥주;송영진;윤영식
    • 반도체디스플레이기술학회지
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    • 제4권3호
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    • pp.11-15
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    • 2005
  • This paper shows that carbon nanotubes can be applied to a nanopipette. Nano space in atomic force microscope multi wall carbon nanotube tips is filled with molecules and atoms with charges and then, the tips can be applied to nanopipette when the encapsulated media flow off under applying electrostatic farces. Since the nano space inside the tips can be refilled, the tips can be permanently used in ideal conditions of no chemical reaction and no mechanical deformation. Molecular dynamics simulations for nanopipette applications demonstrated the possibility of nano-lithography or single-metallofullerene-transistor array fabrication.

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Selective Monitoring of Rutin and Quercetin based on a Novel Multi-wall Carbon Nanotube-coated Glassy Carbon Electrode Modified with Microbial Carbohydrates α-Cyclosophorohexadecaose and Succinoglycan Monomer M3

  • Jin, Joon-Hyung;Cho, Eun-Ae;Kwon, Chan-Ho;Jung, Seun-Ho
    • Bulletin of the Korean Chemical Society
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    • 제31권7호
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    • pp.1897-1901
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    • 2010
  • Multi-wall carbon nanotube (MWNT)-modified glassy carbon electrodes (GCE) were prepared for simultaneous determination of rutin and quercetin. Microbial carbohydrates, $\alpha$-cyclosophorohexadecaose ($\alpha$-C16) and succinoglycan monomer M3 (M3) were doped into MWNTs to prepare a $\alpha$-C16-doped MWNT-modified GCE (($\alpha$-C16 + MWNTs)/GCE) and a M3-doped MWNT-modified GCE ((M3 + MWNTs)/GCE), respectively. The sensitivities of the ($\alpha$-C16 + MWNTs)/GCE to rutin and quercetin were 34.7 ${\mu}A\cdot{\mu}M^{-1}{\cdot}cm^{-2}$ and 18.3 ${\mu}A\cdot{\mu}M^{-1}{\cdot}cm^{-2}$, respectively, in a linear range of $2\sim8{\mu}M$ at pH 7.2. The sensitivities of the (M3 + MWNTs)/GCE was 2.44 ${\mu}A\cdot{\mu}M^{-1}{\cdot}cm^{-2}$ for rutin and 7.19 ${\mu}A\cdot{\mu}M^{-1}{\cdot}cm^{-2}$ for quercetin without interference.