• International Journal of Precision Engineering and Manufacturing
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• v.6 no.2
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• pp.46-49
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• 2005

Recently, many research results have been reported about nano-tip using carbon nanotube because of its better sensing ability compared to a conventional silicon tip. However, it is very difficult to identify the carbon nanotube having proper length for nano-tip and to attach it on a conventional tip. In this paper, a new method is proposed to make a nano-tip and to control its length. The electrochemical etching method was used to control the length by cutting the carbon nanotube of arbitrary length and it was possible to monitor the process through current measurement. The etched volume of carbon nanotube was determined by the amount of applied charge. The carbon nanotube was successfully cut and could be used in the nanogripper.

• 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%.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1126-1129
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• 2004

Because of the various length condition of carbon nanotube, it is very confined the application area of the single CNT tip. In this paper, it was proposed the cutting technique of single CNT tip and the relationship between the etched volume and the amount of the applied charge. It is possible to control the length of single CNT tip arbitrary using this technique. The etched volume and length in the single CNT tip can be predicted with the amount of the applied charge. It is very easy to make a single CNT tip with proper length using this technique and to make nanotweezer that was composed two single CNT tips.

• Journal of Electrical Engineering and Technology
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• v.3 no.1
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• pp.115-120
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• 2008

Use of the carbon nanotube is superior to general powder state materials of mechanical and electrical properties. Because its ratio of diameter and length (aspect ratio) is very large, it has been known as a type of ideal nano-reinforcement material. Based on this advantage, the existing carbon black of semiconductive shield materials used in power cables can acquire excellent properties by using a small amount of carbon nanotubes. Thus, we investigated the thermal properties of the carbon nanotube, such as thermal conductivity, specific heat, and DSC (Differential Scanning Calorimetry). We found that a high thermal resistance level is demonstrated by using a small amount of carbon nanotubes. As a result, this tendency confirms high cross-linking density in a new network in which the carbon nanotube between carbon black constitute molecules shows a bond by similar constructive properties.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.45.2-45.2
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• 2010

Possessing of carbon nanotubes in biopolymer intrigued much interest due to their mechanical and unique nanoscale surface properties. Surface stiffness can be controlled by the amount of carbon nanotubes in polymer and surface wettability can be altered by the order of nanoscale surface roughness. Protein adsorption mechanism on nanostructured carbon nanotube/polymer thin film will be discussed in this study. In addition, we identified that mechanical stimuli also contribute the messenchymal stem cell and bone cell interactions. Importantly, live cell analysis system also showed altered morphology and cellular functions. Thus, embedding of carbon nanostructures simultaneously contribute to protein adsorption and cellular interactions. In conclusion, this study demonstrated the evidence that nanoscale surface features determine the subsequent biological interactions, such as protein adsorption and cellular interactions.

• Advances in nano research
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• v.14 no.5
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• pp.443-450
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• 2023

Carbon nanotubes (CNTs) have received increased interest in reinforcing research for polymer matrix composites due to their exceptional mechanical characteristics. Its high surface area/volume ratio and aspect ratio enable polymer-based composites to make the most of its features. This study focuses on the experimental tensile testing and fabrication of carbon nanotube reinforced composite (CNTRC) beams, exploring various micromechanical models. By examining the performance of these models alongside experimental results, the research aims to better understand and optimize the mechanical properties of CNTRC materials. Tensile properties of neat epoxy and 0.3%; 0.4% and 0.5% by CNT reinforced laminated single layer (0°/90°) carbon fiber composite beams were investigated. The composite plates were produced in accordance with ASTM D7264 standard. The tensile test was performed in order to see the mechanical properties of the composite beams. The results showed that the optimum amount of CNT was 0.3% based on the tensile capacity. The capacity was significantly reduced when 0.4% CNT was utilized. Moreover, the experimental results are compared with Finite Element Models using ABAQUS. Hashin Failure Criteria was utilized to predict the tensile capacity. Good conformance was observed between experimental and numerical models. More importantly is that Young' Moduli of the specimens is compared with the prediction Halpin-Tsai and Mixture-Rule. Although Halpin-Tsai can accurately predict the Young's Moduli of the specimens, the accuracy of Mixture-Rule was significantly low.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.28-33
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• 2009

Carbon nanotube supported molybdenum carbide catalysts were prepared as a function of various preparation conditions and characterized, and their catalytic activities were compared through electrochemical oxidation of methanol. To overcome the low activity of a transition metal catalyst, carbon nanotube was used as a support, and the amount and the kind of precursors, acid treatment method, and carburization temperature were varied for the catalyst preparation. ICP-AES, XRD and TEM were used for the catalyst characterization. Based on the various preparation methods of carbon nanotube supported molybdenum carbide catalysts ($Mo_2C/CNT$), the size and the amount of supported catalysts could be controlled, and their effects on the electrochemical oxidation could be explained.

• Polymer(Korea)
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• v.34 no.6
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• pp.534-539
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• 2010

Polystyrene (PS)/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared via latex technology and the effect of nanotube length on rheological properties were investigated. Monodisperse PS particle was synthesized by the emulsifier-free emulsion polymerization and two types of MWCNTs were used after surface modification to improve dispersion state and to remove impurities. Final nanocomposites were prepared by the freeze-drying process after dispersing the PS particles and the surface-modified MWCNTs in a ultrasonic bath. The effects of MWCNT content and nanotube length on rheological properties were evaluated by imposing the small-amplitude oscillatory shear flow. The PS/MWCNT nanocomposites showed that rheological properties were enhanced as the amount and length of MWCNT increased. It is speculated that the rheological characteristics of nanocomposites change from liquid-like to solid-like as the MWCNT amount increases, and the critical concentration to achieve network structure decreases as the nanotube length increases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.739-744
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• 2007

In this paper, we have investigated mechanical and chemical properties by changing the content of carbon nanotube, which is component part of semiconductive shield in underground power transmission cable. Specimens were made of sheet with the eight of those for measurement. The condition of specimens was a solid sheet. Chemical properties of specimens was measured by FT-ATR (Fourier Transform Attenuated Total Reflectance). Stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400[Kgf/Cm] and 600[%]. We could observe (unctional group (C=O, carbonyl group) of specimens through FT-ATR. From these experimental result, the concentration of functional group [C=O] was high accor야ng to increasing the content of carbon nanotube. We could know CNT/EEA was excellent more than other specimens from above experimental results. In Addition, the elongation ratio was decreased, and yield strength was increased according to increasing the content of carbon nanotube. Also, from these experimental result, we could know that a small amount of CNT/EEA has a excellent mechanical and chemical properties.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.3
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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.