• Carbon letters
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• v.11 no.2
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• pp.117-121
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• 2010

The composites of alginate, carbon nanotube, and iron(III) oxide were prepared for the removal of heavy metal in aqueous pollutant. Both alginate and carbon nanotube were used as an adsorbent material and iron oxide was introduced for the easy recovery after removal of heavy metal to eliminate the secondary pollution. The morphology of composites was investigated by FE-SEM showing the carbon nanotubes coated with alginate and the iron oxide dispersed in the alginate matrix. The ferromagnetic properties of composites were shown by including iron(III) oxide additive. The copper ion removal was investigated with ICP AES. The copper ion removal efficiency increased greatly over 60% by using alginate-carbon nanotube composites.

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.488-493
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• 2009

We developed a simple method to control the length of carbon nanotube array by using oxygen plasma etching. In this way, we could obtain a carbon nanotube with a uniform length (20, 30, 50, $70\;{\mu}m$), that was parallel to the substrate. Moreover, our growing method of carbon nanotube array gives a uniform diameter ~3.5nm, which is consistent with our previous results. Using the same etching method, we demonstrated the carbon nanotube radio frequency identification (RFID) antenna. The results could be useful for carbon nanotube applications such as flexible and transparent conductive films.

• Korean Journal of Materials Research
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• v.18 no.5
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• pp.253-258
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• 2008

A simple method to deposit carbon nanotube films uniformly on large area substrates using an arc discharge method is reported in this paper. The arc discharge method was modified to deposit carbon nanotube films in situ on the substrates. The substrates were scanned several times over the arcing point for a uniform film thickness. Deposition was carried out under variable dc bias conditions at 600 torr of $H_2$ gas. The thickness uniformity of the single-wall carbon nanotube films as characterized by a four-point probe was within 30% deviation. The morphology and crystal quality of the single-wall carbon nanotube film were also characterized by field emission scanning electron microscopy and Raman spectroscopy.

• Carbon letters
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• v.15 no.4
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• pp.255-261
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• 2014

Multi-walled carbon nanotube reinforced epoxy composites were fabricated using shear mixing and sonication. The mechanical, viscoelastic, thermal, and electrical properties of the fabricated specimens were measured and evaluated. From the images and the results of the measurements of tensile strengths, the specimens having 0.6 wt% nanotube content showed better dispersion and higher strength than those of the other specimens. The Young's moduli of the specimens increased as the nanotube filler content was increased in the matrix. As the concentrations of nanotubes filler were increased in the composite specimens, their storage and loss moduli also tended to increase. The specimen having a nanotube filler content of 0.6 wt% showed higher thermal conductivity than that of the other specimens. On the other hand, in the measurement of thermal expansion, specimens having 0.4 and 0.6 wt% filler contents showed a lower value than that of the other specimens. The electrical conductivities also increased with increasing content of nanotube filler. Based on the measured and evaluated properties of the composites, it is believed that the simple and efficient fabrication process used in this study was sufficient to obtain improved properties in the specimens.

• 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.

• 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.

• Carbon letters
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• v.10 no.1
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• pp.1-4
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• 2009

In this work, standardization trends related carbon nanotubes and international standardization activities in the ISO/TC229 and IEC/TC113 were introduced. The movement toward development of carbon nanotube standard began in the nanotechnology council under the IEEE in 2005. KATS has also run the carbon nanotube standardization committee to support commercialization of product containing carbon nanotube through standards since 2004. The Korean Standards such as KSD2711, 2712, 2717 were established.

• Journal of the Korean Ceramic Society
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• v.46 no.6
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• pp.541-544
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• 2009

In Part III, the paper will show that an alumina-carbon nanotube-niobium nanocomposite produced fracture toughness values that are several times higher than that of pure nanocrystalline alumina. It was possible to take advantage of both fiber-toughening and ductile-metal toughening in this investigation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.467-474
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• 2020

Carbon nanotube has excellent mechanical strength and functionality, so it has been utilized in various applications. In recent years, utilization of carbon nanotube in construction material has started to get interests from researchers in the area of construction materials. However, there is limited amount of work with respect to the rheological properties of cement paste using carbon nanotube. In this work, solution made of multi-walled carbon nanotube with dispersing agent of polyvinyl pyrrolidone was used to prepare cement paste specimens, and rheological properties and 28 day compressive strengths of cement paste using multi-walled carbon nanotube were measured. According to the experimental results, as the amounnt of multi-walled carbon nanotube increased, plastic viscosity and yield stress of cement paste specimens also increased. It was also found that such effect was higher with lower w/c cement paste specimens. With respect to the compressive strength, it was maximized at carbon nanotube content of 0.1wt.% for w/c 0.30 cement paste, whereas the maximum strength of w/c 0.40 cement paste was observed with carbon nanotube content of 0.2wt%.

• 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.