• Title, Summary, Keyword: Nanotube

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Synthesis of SiC Nanotube by CNT-confined Reaction (CNT-confined reaction에 의한 탄화규소 나노튜브의 합성)

  • Rho Dae-Ho;Kim Jae-Soo;Byun Dong-Jin;Yang Jae-Woong;Kim Na-Ri
    • Korean Journal of Materials Research
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    • v.14 no.3
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    • pp.175-180
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    • 2004
  • SiC nanotubes were synthesized by CNT-confined reaction. Evaporated SiO gas reacted with carbon nanotubes by VS growth mechanism. By confineded reaction, carbon nanotube was changed to SiC nanotube, and synthesized SiC nanotube was filled partly by the gas reaction in the nanotubes. SiC nanotube's mean diameters were not changed than carbon nanotubes because of means ratio of $CO_2$ and SiO gas was maintained evenly during the process. This result was same of data of simulation. By TEM observastion, SiC nanotube was filled by reaction of inner wall of CNT and SiO gas through the VS reactions. Converted SiC nanotube's compositions were revealed Si and C of 1: 1 ratios at all sites of nanotube by EDS.

Output Characteristics of Carbon-nanotube Field-effect Transistor Dependent on Nanotube Diameter and Oxide Thickness (나노튜브 직경과 산화막 두께에 따른 탄소나노튜브 전계 효과 트랜지스터의 출력 특성)

  • Park, Jong-Myeon;Hong, Shin-Nam
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.2
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    • pp.87-91
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    • 2013
  • Carbon-nanotube field-effect transistors (CNFETs) have drawn wide attention as one of the potential substitutes for metal-oxide-semiconductor field-effect transistors (MOSFETs) in the sub-10-nm era. Output characteristics of coaxially gated CNFETs were simulated using FETToy simulator to reveal the dependence of drain current on the nanotube diameter and gate oxide thickness. Nanotube diameter and gate oxide thickness employed in the simulation were 1.5, 3, and 6 nm. Simulation results show that drain current becomes large as the diameter of nanotube increases or insulator thickness decreases, and nanotube diameter affects the drain current more than the insulator thickness. An equation relating drain saturation current with nanotube diameter and insulator thickness is also proposed.

Modification of Carbon Nanotube for the Improvement of Dispersion and the Dispersion Characteristics of Carbon Nanotube in Polyurethane (분산성 향상을 위한 탄소나노튜브의 개질과 폴리우레탄과의 분산 특성)

  • Park, Kyung-Soon;Kim, Seung-Jin;Kim, Jeong-Hyun;Park, Jun-Hyeong;Kwon, Oh-Kyung
    • Textile Coloration and Finishing
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    • v.22 no.1
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    • pp.43-50
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    • 2010
  • The thermal treatment for carbon nanotube was applied to remove the water, metal catalyst and other impurities in carbon nanotube. The surface of carbon nanotube was changed into open structure with acid treatment by mixed solution of $HNO_3$ and $H_2SO_4$. The dispersion property of the functionalized and modified carbon nanotube was assessed with naked eyes by dispersing it in DMF. Carbon nanotube mixd polyurethane film was made to estimate the dispersion property by reflectance of the film with UV-Vis spectrometer. Also the internal structure of carbon nanotube was observed with SEM and TEM and thermal pyrolysis property of the carbon nanotube was measured by TGA and DSC. The surface modification of carbon nanotube by thermal and acid treatments improved the dispersion property of carbon nanotube/polyurethane mixed materials.

The Development of High Performance Nano-composites with Carbon Nanotube (카본나노튜브를 이용한 고성능 나노복합재료의 개발 동향)

  • Lee, Min-Kyung;Bae, Soo Bin;Park, Jong Kyoo;Lee, Seung Geol
    • Textile Coloration and Finishing
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    • v.26 no.2
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    • pp.71-78
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    • 2014
  • This review paper is a state of the art report of the development of high performance nano-composites with carbon nanotube. We investigate the research and development (R&D) trends of high performance nano-composites with carbon nanotube by analyzing technical trends in research institutes and industry. We report the R&D and technology trends for the properties and applications of fabrication of hybrid composites with aligned carbon nanotubes, multifunctional fiber/carbon nanotube composites. We discuss the specific topics including unidirectional carbon nanotube, carbon nanotube forests, transfer-printing carbon nanotube technology, deposition of carbon nanotube by electrophoresis, vapor grown carbon fiber (VGCF), cup-stacked carbon nanotube, bucky paper and carbon nanotube yarns in this review paper.

Evaluation of OH Radical Generation to Nanotube Morphology of TiO2 Nanotube Plate (TiO2 nanotube plate의 nanotube 형태에 따른 OH radical 생성량 평가)

  • Lee, Yongho;Pak, Daewon
    • Journal of Korean Society on Water Environment
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    • v.32 no.5
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    • pp.403-409
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    • 2016
  • In this study, a TiO2 nanotube was grown on a titanium plate by using anodic oxidation method for the evaluation of TiO2 nanotube morphology. The TiO2 nanotube was grown in an electrolyte containing ethylene glycol, 0.2 wt% of NH4F and 2 vol% of H2O. Applied voltage varied from 30 to 70 V and the morphology of the TiO2 nanotube was observed. After anodization, a TiO2 nanotube plate was immersed in 35℃ ethanol for 24 hours. Anatase and rutile crystal forms of TiO2 nanoutbe were observed after annealing. 4-chrolobenzoic acid, a probe compound for OH radicals, was dissolved in H2O in order to measure the OH radical. Liquid chromatography was used to check the concentration of the 4-chrolobenzoic acid. The OH radical generation by TiO2 nanotube plate was proportionate to the length of the TiO2 nanotube. Furthermore, when the number of TiO2 nanotube plate increased, the OH radical generation increased as well.

Comparison of OH radical generation depending on anatase to rutile ratio of TiO2 nanotube Photocatalyst (Anatase와 Rutile 결정상 비율에 따른 TiO2 nanotube의 OH radical 생성량 비교 연구)

  • Lee, Hyojoo;Lee, Yongho;Pak, Daewon
    • Journal of Korean Society on Water Environment
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    • v.35 no.6
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    • pp.550-556
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    • 2019
  • This study was carried out to improve the photocatalytic reaction of TiO2 photocatalyst. During the photocatalytic reaction, OH radicals are generated and they have an excellent oxidation capability for wastewater treatment. To evaluate the OH radicals generated according to crystallographic structure of TiO2 nanotubes photocatalyst, a probe compound, 4-Chlorobenzoic acid was monitored to evaluate OH radical. Ultraviolet light was applied for photocatalytic reaction of TiO2. The 4-Chlorobenzoic acid solution was prepared at laboratory. TiO2 nanotube was grown on titanium plate by using anodization method. The annealing temperature for TiO2 nanotube was varied from 400 to 900 ℃ and the crystal forms of the TiO2 nanotube was analyzed. Depending on annealing temperature, TiO2 nanotubes have shown different crystal forms; 100% anatase (0 % rutile), 18.4 % rutile (81.6 % anatase), 36.6 % rutile (63.4 % anatase) and 98.6% rutile (1.4% anatase). As the annealing temperature increases, the rutile ratio increases. OH radical generation from 18.4 % rutile TiO2 nanotube plate was about 3.8 times higher than before annealing and 1.4 times higher than only 100 % anatase-TiO2 nanotube. The efficiency of the 18.4% rutile TiO2 nanotube was the best in comparison to TiO2 nanotube with 18.4 %, 36.6 % and 98.6 % rutile. As a result, photocatalytic ability of 18.4 % rutile-TiO2 nanotube plate was higher than 100 % anatase-TiO2 nanotube plate.

Frequency Vibrational Behavior Analysis of Double-Wall Carbon Nanotube Resonator (이중벽 탄소 나노튜브 공진기의 주파수 변동 특성 분석)

  • Kim, Jin-Tae;Lee, Jun-Ha
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.1
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    • pp.169-174
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    • 2011
  • For a double-walled carbon nanotube resonator with a short outer nanotube, the free edge of the short outer wall plays an important role in the vibration of the long inner nanotube. For a double-walled carbon nanotube resonator with a short inner nanotube, the short inner nanotube can be considered as a flexible core, thus, the fundamental frequency is influenced by its length. In this paper, we analysis frequency variation in ultrahigh frequency nanomechanical resonators based on double-walled carbon nanotubes with different wall length. This results will widely apply to the realization of frequency devices controlling the length of the inner or outer nanotube.

Research Status on the Carbon Nanotube Reinforced Nanocomposite (탄소나노튜브 강화 나노복합재료의 연구현황)

  • 차승일;김경태;이경호;모찬빈;홍순형
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.25-28
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    • 2003
  • Carbon nanotubes(CNTs), since their first discovery, have been considered as new promising materials in various fields of applications including field emission displays, memory devices, electrodes, NEMS constituents, hydrogen storages and reinforcements in composites due to their extra-ordinary properties. The carbon nanotube reinforced nanocomposites have attracted attention owing to their outstanding mechanical and electrical properties and are expected to overcome the limit of conventional materials. Various application areas are possible for carbon nanotube reinforced nanocomposites through the functionalization of carbon nanotubes. Carbon nanotube reinforced polymer matrix nanocomposites have been fabricated by liquid phase process including surface functionalization and dispersion of CNTs within organic solvent. In case of carbon nanotube reinforced polymer matrix nanocomposites, the mechanical strength and electrical conducting can be improved by more than an order of magnitude. The carbon nanotube reinforced polymer matrix nanocomposites can be applied to high strength polymers, conductive polymers, optical limiters and EMI materials. In spite of successful development of carbon nanotube reinforced polymer matrix nanocomposites, the researches on carbon nanotube reinforced inorganic matrix nanocomposites show limitations due to a difficulty in homogeneous distribution of carbon nanotubes within inorganic matrix. Therefore, the enhancement of carbon nanotube reinforced inorganic nanocomposites is under investigation to maximize the excellent properties of carbon nanotubes. To overcome the current limitations, novel processes, including intensive milling process, sol-gel process, in-situ process and spark plasma sintering of nanocomposite powders are being investigated. In this presentation, current research status on carbon nanotube reinforced nanocomposites with various matrices are reviewed.

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Damping Characterization of Carbon Nanotube/Epoxy Composites (탄소나노튜브/에폭시 복합소재의 감쇠특성 분석)

  • Shin, Eung-Soo;Lee, Jong-Hwa
    • Proceedings of the KSME Conference
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    • pp.497-502
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    • 2003
  • This study intends to provide the analytical and experimental damping characterization of carbon nanotube/epoxy composites. A constitutive model based on continuum mechanics is employed to describe epoxy and the perfectly bonded and partially bonded nanotubes. An interfacial stick-slip between the nanotubes and epoxy is considered to characterize the damping of the composites. For experimental estimation, beam-type specimens are prepared with a variation of nanotube concentration from 0.5% to 2% in weight. An ultrasonic agitation method is employed for enhancing the nanotube dispersion within epoxy. Damping of the composites is characterized in terms of the strain and the nanotube concentration. Results show that the nanotube concentration significantly affects the damping characteristics of the nanocomposites. A good correlation is found between the analytical prediction based on the stick-slip and the experimental measurements.

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Theoretical Analysis of Carbon Nanotube Actuators (탄소나노튜브 작동기의 이론적 해석)

  • Park C.H.;Park H.C.;So H.K.;Jung B.B.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.927-931
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    • 2005
  • Carbon nanotube actuator, working under physical conditions (in aqueous solution) and converting electrical energy into mechanical energy directly, can be a good substitute for artificial muscle. The carbon nanotube actuator simulated in this paper is an isotropic cantilever type with an adhesive tape which is sandwiched between two single-walled carbon nanotubes. For predicting the static and dynamic characteristic parameters, the analytical model for a 3 layer bimorph carbon nanotube actuator is developed by using Euler-Bernoulli beam theory. The governing equation and boundary conditions are derived from energy principles. The induced displacements of the theoretical model are presented in order to investigate the performance of the carbon nanotube actuator with different control voltages. The developed model presents invaluable means for designing and predicting the performance of carbon nanotube actuator that can be used in artificial muscle applications.

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