• 마이크로전자및패키징학회지
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• 제11권1호
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• pp.59-64
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• 2004

고분자 전해질 연료전지의 성능은 촉매 지지 물질의 특성에 의존한다. 본 연구에서는 백금 촉매의 지지체로서 CNF(carbon nanofibre)와 CNT(carbon nanotube)를 사용하였다. CNF와 CNT는 기상화학증착법과 메카노케미컬 공정에 의해 처리된 촉매를 이용하여 합성되었다. 백금은 고분자 전해질 연료전지의 적용을 위하여 CNF와 CNT로 지지되었다. 그 결과, 65 nm의 직경을 가지는 twisted CNF로 준비된 MEA가 가장 우수한 I-V 특성을 나타내는 것이 확인되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.772-774
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• 2007

The improvement in the field emission parameters, luminescent uniformity, degradation rate and half life has been observed for the thin-multi wall carbon nanotube (t-MWCNT) composite, after incorporating the Zn nanoparticles. The Zn nanoparticles $(diameter\;{\sim}\;100\;{\pm}15\;nm)$ has been incorporated to synthesize the Zn-t-MWCNT composite.

• 열처리공학회지
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• 제33권6호
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• pp.290-295
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• 2020

In this study, Electro spinning was carried out using Cabon nanotube 0.1%-Polyacrylonitrile 3%-Dimethylformamide 17% agitation solution. It was investigated the solute and solvent correlations according to the electro spinning voltages ranging form 5 to 40 kV, based on the SEM image. Except voltage 25 kV, electro spinning was failed due to the lack of electro spinning (less than 60%). Voltage 25 kV was showed excellent properties, and was confirmed Cabon nanotube 58.1 nm and diameter of Cabon nanotube + Polyacrylonitrile 1.76 ㎛ as shown SEM image. Also, the tensile test results were showed that SK Chemical prepreg electro spinning angle of 0 and 90 degrees were 137 MPa and 60 MPa, respectively.

• Transactions on Electrical and Electronic Materials
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• 제9권4호
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• pp.169-172
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• 2008

We attempted to fabricate carbon nanotube field effect transistor (CNT-FET) using single walled carbon nanotube(SWNT) on the heavily doped Si substrate used as a bottom gate, source and drain electrode were fabricated bye-beam lithography on the 500 nm thick $SiO_2$ gate dielectric layer. We investigated electrical and physical properties of this CNT-FET using Scanning Probe Microscope(SPM) and conventional method based on tungsten probe tip technique. The gate length of CNT-FET was 600 nm and the diameter of identified SWNT was about 4 nm. We could observed gating effect and typical p-MOS property from the obtained $V_G-I_{DS}$ curve. The threshold voltage of CNT-FET is about -4.6V and transconductance is 47 nS. In the physical aspect, we could identified SWNT with phase mode of SPM which detecting phase shift by force gradient between cantilever tip and sample surface.

• 한국수소및신에너지학회논문집
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• 제14권3호
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• pp.247-257
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• 2003

To investigate the effect of preparing condition on the physical properties of carbon nanotubes suitable for optical applications, carbon nanotubes were synthesized by thermal chemical vapor deposition using Ni particles as a catalyst on stainless steel substrate and acetylene as a reactant gas. To examine the physical and optical properties, SEM, TEM, Ram an, UV-visible, and photoluminescence spectroscopy were used. The physical properties of carbon nanotubes such as diameter, degree of growth density and morphology were closely related to such experimental conditions as Ni particle size, growing pressure, and etching condit on of Ni particles, it appeared from the light absorbance and photoluminescence spectra of carbon nanotube mixture prepared with an addition of a photopolymer, P3HT(Poly(3-hexylthIop hene)) that carbon nanotube could do a role as a kind of electron acceptor for solar cell application.

• Steel and Composite Structures
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• 제45권5호
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• pp.641-652
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• 2022

Fluid-conveying tubes are widely used to transport oil and natural gas in industries. As an advanced composite material, functionally graded carbon nanotube-reinforced composites (FG-CNTRC) have great potential to empower the industry. However, nonlinear free vibration of the FG-CNTRC fluid-conveying pipe has not been attempted in thermal environment. In this paper, the nonlinear free vibration characteristic of functionally graded nanocomposite fluid-conveying pipe reinforced by single-walled carbon nanotubes (SWNTs) in thermal environment is investigated. The SWCNTs gradient distributed in the thickness direction of the pipe forms different reinforcement patterns. The material properties of the FG-CNTRC are estimated by rule of mixture. A higher-order shear deformation theory and Hamilton's variational principle are employed to derive the motion equations incorporating the thermal and fluid effects. A two-step perturbation method is implemented to obtain the closed-form asymptotic solutions for these nonlinear partial differential equations. The nonlinear frequencies under several reinforcement patterns are presented and discussed. We conduct a series of studies aimed at revealing the effects of the flow velocity, the environment temperature, the inner-outer diameter ratio, and the carbon nanotube volume fraction on the nature frequency.

• 한국정밀공학회지
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• 제23권3호
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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.

• Carbon letters
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• 제10권4호
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• pp.320-324
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• 2009

We investigated the effect of diameter and content of carbon nanotubes (CNTs) on the physical properties of styrenebutadiene rubber (SBR)/CNTs nanocomposites. CNTs-reinforced SBR nanocomposites were prepared by the melt mixing process. CNTs with different diameters were synthesized by the chemical vapor deposition method (CVD). In this work, the mechanical property and other physical properties of SBR/CNTS nanocomposites were discussed as a function of the content and diameter of CNTs.

• Korean Chemical Engineering Research
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• 제55권5호
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• pp.646-651
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• 2017

CNT 유동층 반응기(내경 0.15 m, 높이 2.6 m) 희박상 내 CNT 입자(평균입도 $291{\mu}m$, 벌크밀도 $72.9kg/m^3$)의 거동을 확인하기 위해 레이저 슬릿광 형상 측정법을 이용하여, CNT 응집체의 크기 및 형태를 측정하였다. 기포유동층 조건에서 CNT 반응기 내 축방향 고체체류량 분포는 하부 농후상과 상부 희박상을 갖는 S자 형태를 보였다. 기체 유속이 증가할수록 비산되는 CNT 응집체의 Heywood 직경과 Feret 직경이 증가하였고, 응집체 내 CNT 입자수가 증가하였다. 또한, 기체의 유속이 증가할수록 CNT 응집체의 종횡비는 증가하고, 원형도는 감소하였다. CNT 응집체의 원마도와 견고도는 기체의 유속이 증가할수록 감소하였다. 응집체의 형상 분석 정보에 기반한 희박상 내 응집체 형성 원인을 제안하였다.

• 한국진공학회지
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• 제22권3호
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• pp.144-149
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• 2013

단일 벽 탄소 나노튜브(SWNT)의 열전도도를 구하기 위해서 메모리함수에 Kubo 등식을 사용하였다. 계산 과정에서 나타나는 발산의 문제를 해결하기 위해 전파인자는 연속 분수과정으로 전개하였다. 이러한 계산에서 메모리함수는 지금까지 제시된 다른 이론들 보다 많은 상호작용의 효과를 고려할 수 있다. SWNT에서 20 K 이하의 저온 영역은 온도의 증가에 따라 열전도도가 증가하며, (9,0) 보다 (10,0)이 다소 큰 값을 가지는데 이는 포논의 평균자유행로 $l_{ph}$가 직경의 크기와 관계 있음을 알 수 있다. 그리고 20 K 이상의 고온 영역에서는 비열이 거의 일정한 값을 가지므로 Umklapp 과정에 의해 열전도도는 감소하면서 최대값을 보이고, SWNT의 직경이 증가할수록 최대값의 위치도 고온 쪽으로 이동하는 것으로 조사되었다.