• Korean Chemical Engineering Research
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• 제46권5호
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• pp.898-902
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• 2008

Polyaniline(PAN), multi-walled carbon nanotube(CNT)/PAN, $CNT/PAN/RuO_2$로 구성된 초고용량캐폐시터 전극을 제조하여 cyclic voltammetry(CV)를 이용하여 1 M $H_2SO_4$ 수용액에서 캐패시턴스 특성을 조사하였다. PAN, CNT/PAN 그리고 $CNT/PAN/RuO_2$ 복합전극은 높은 주사속도인 1,000 mV/s에서 199, 304, 392 F/g의 비용량을 각각 나타내었다. 수명시험 결과, $CNT/PAN/RuO_2$, CNT/PAN, PAN 전극은 10,000 번의 싸이클에서 각각 61, 66 그리고 51%의 초기용량을 유지하였다. PAN 전극은 CNT와 복합화하여 축전용량 및 수명특성을 향상시킬 수 있으며, $RuO_2$ 도입은 축전용량 향상에는 기여하나 수명 증가 효과는 미미하였다.

• 전기학회논문지
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• 제56권3호
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• pp.571-576
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• 2007

In this paper, we have investigated chemical, mechanical and structural properties by changing the content of carbon nanotube, Which is a component part of semiconductive shield in underground power transmission cable. The multi luminescence spectrometer MLA-GOLDS was used to investigate chemical properties of specimens. Also, the density meter EW-200SG was used to investigate the mechanical properties of specimens, and the FE-SEM S-4300 in Hitachi was used for dispersion of CNT(Carbon nanotube). As a result, the cl intensity, which show the effect of oxidation, was decreased by CNT of 1 [wt%], and the density of semiconductive shield materials with CNT and EEA(Ethylene Ethyl Acrylate) is lower than that for commercial semiconductive shield materials. Also, the properties of dispersion showed an increase according to an increase in the ratio of CNT, and the properties were the best at 5 wt%. Therefore, excellent chemical, mechanical and structural properties can be improved with the small amount of CNT.

• 한국지반환경공학회 논문집
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• 제18권12호
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• pp.59-63
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• 2017

국내 한랭지역(강원권)의 경우 낮은 연평균 기온으로 인해 도로표면이 자주 결빙된다. 특히 터널의 입출구의 도로면은 지형적 영향으로 그늘이 생기기 때문에 타 도로면에 비해 결빙이 많이 발생하게 된다. 이러한 결빙을 방지하기 위해 염수분사장치, 전열선 설치, 지열이용 등이 주로 사용되고 있다. 하지만 이런 방법들은 환경오염, 많은 공사비, 유지보수비 및 정기적인 점검 등의 문제점들이 있다. 본 연구에서는 기존도로의 결빙을 방지하기 위해 발열체인 CNT를 이용하여 콘크리트 슬래브의 발열효과를 살펴보고 최적의 CNT설치 간격을 결정하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.328-331
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• 2000

Carbon nanotube(CNT) was successfully grown on Ni-W alloyed substrate by applying PECVD technique(Plasma Enhanced Chemical Vapor Deposition). As a catalyst, Ni-W alloyed substrate was prepared by mechanical alloying method. In order to find the optimum growth condition, initially two different types of gas mixtures such ac $C_2$H$_2$-H$_2$and $C_2$H$_2$-MH$_3$were systematically investigated by adjusting results on the mixing ratio in temperature range of 500 to 80$0^{\circ}C$. In this work, we will report the preliminary results on the CNT processed by PECVD, which were characterized by XRD, SEM and TEM. Finally we will evalute the effect on CNT growth by changing many processing parameters, such as typical gas, mixing ratio between 2 mixture, plasma power and etc.

• 한국재료학회지
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• 제16권1호
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• pp.37-43
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• 2006

Carbon nanotube cathodes (CNT cathodes) were fabricated by a screen printing method using multi-walled carbon nanotubes. The effects of surface treatment on CNT cathodes were investigated for use in high efficiency field emission displays. The optimum surface treatment for a CNT cathode is dependent on a relative bonding force of CNT films on the cathode after a heat treatment. Because of the high bonding force used in the Liquid method, this method is recommended for CNT cathodes which are heat-treated at $390^{\circ}C$ in a $N_2$ atmosphere. The Rolling method is applicable for CNT cathodes fabricated at $350^{\circ}C$ in an atmosphere of air. The results of this study provide basic criteria for the selection of an appropriate surface treatment for large area CNT cathodes.

• 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.

• 한국세라믹학회지
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• 제44권4호
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• pp.198-201
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• 2007

Multi-walled carbon nanotube (M-CNT)/Nafion nanocomposites were prepared by solution casting to elucidate the effect of M-CNT addition, from 0 to 7 wt%, on the viscoelastic behavior of the composites. The M-CNT bundles induced by the Nafion polymer were determined to be uniformly distributed for the 1 wt% M-CNT/Nafion nanocomposites. The 1 wt% M-CNT/Nafion composite exhibited the highest blocking stress of 2.3 kPa due to its high elastic modulus of 0.485 GPa. From a dynamic mechanical analysis, the 1 wt% M-CNT had the highest storage and loss moduli compared with the other samples in all frequency and temperature ranges. From the storage modulus data, the M-CNT loaded composites had similar $T_g$ values near $120^{\circ}C$. The glass transition temperatures of the M-CNT loaded composites were $120^{\circ}C$ (1 wt%), $117^{\circ}C$ (3 wt%), $117^{\circ}C$ (5 wt%), and $135^{\circ}C$ (7 wt%), suggesting that the effect of the M-CNTs on the Nafion film begins at 1 wt%. Thus, it has been concluded that the 1 wt% M-CNT disported composite is attractive for actuator applications.

• 한국재료학회지
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• 제13권10호
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• pp.663-667
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• 2003

The effects of paste materials on field emission properties in a carbon nanotube(CNT) cathode were investigated for high-efficient field emission displays. The major components in CNT paste for screen printing were a metallic Ag-paste, a dielectric glass-frit and CNT ink. The emission current from the cathode by an electron tunneling effect increased with an increase in the dielectric material fraction in the CNT paste, which is related to an increase of field enhancement factor in Fowler-Nordheim equation. The surface treatment used, after soft baking of the screen-printed CNT films, greatly affected the decrease in the turn-on field in CNT cathode and the uniformity of emission sites over the entire CNT film area.

• Journal of Electrochemical Science and Technology
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• 제2권4호
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• pp.211-215
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• 2011

Flexible sheets consisting of acrylonitrile-butadiene rubber (NBR) and carbon nanotube (CNT) are newly prepared varying the composition (CNT 20-25 wt.%) for use as a current collector of supercapacitor electrodes. The as-prepared CNT/NBR is electrodeposited with aniline using potentiodynamic cyclic voltammetry to yield a polyaniline (PANI)/CNT/NBR composite electrode. It is confirmed that the electrical conductivity of CNT/NBR current collector can be enhanced as the content of CNT increases. Cyclic voltammetry result shows that the sample of PANI/CNT(25 wt.%)/NBR composite achieves a maximum specific capacitance ($134.9\;F\;g^{-1}$) at $5\;mV\;s^{-1}$. Such supercapacitor application is possibly originated from the synergistic effects consisting of higher polarity of nitrile groups in NBR, conducting pathway of CNT, and electroactive property of PANI.

• 한국전기전자재료학회논문지
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• 제35권3호
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• pp.269-274
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• 2022

We prepared carbon nanotube (CNT) paper by a vacuum filtration method for the use of a chip-typed resistor as a precision passive device with a constant resistance. Hybrid resistor composed of the CNT resistor with a negative temperature coefficient of resistance (T.C.R) and a metal alloy resistor with a positive T.C.R could lead to a constant resistance, because the resistance increase owing to the temperature increase at the metal alloy and decrease at the CNT could counterbalance each other. The constant resistance for the precision passive devices should be maintained even when a heat was generated by a current flow resulting in resistance change. Performance reliabilities of the CNT resistor for the precision passive device applications such as electrical load limit, environmental load limit, and life limit specified in IEC 60115-1 must be ensured. In this study, therefore, the rated power determination and T.C.R tests of the CNT paper were conducted. -900~-700 ppm/℃ of TCR, 0.1~0.2 A of the carrying current capacity, and 0.0625~0.125 W of the rated power limit were obtained from the CNT paper. Consequently, we confirmed that the application of CNT materials for the precision hybrid passive devices with a metal alloy could result in a better performance reliability with a zero tolerance.