• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.487-493
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• 2010

There has been a controversy on the formation mechanism of $TiO_2$ nanotubes. This study was conducted to elucidate the formation mechanism of $TiO_2$ nanotubes. $TiO_2$ nanotubes were prepared by a hydrothermal method. $TiO_2$ nanotubes formation mechanism was investigated by controlling the formation time. It was found that $TiO_2$ nanotubes were formed by growing, not by wrapping of sheets. The phase structure of hydrogen titanate nanotubes was different from that of $TiO_2$ nanotubes. It is important to wash the sodium titanate nanotubes with an acidic solution to get hydrogen titanate nanotubes and then to calcine the hydrogen titanate nanotubes around $400^{\circ}C$ to obtain $TiO_2$ nanotubes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.663-667
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• 2005

Surface modified carbon nanotubes were applied into the epoxy composites to investigate its tribological property. Carbon nanotubes reinforced epoxy composites were fabricated by casting. Effects to the tribological property of loading concentrations and types of surface modification of carbon nanotubes were investigated under sliding condition using linear reciprocal sliding wear tester. The results show that the small amount of carbon nanotubes into the epoxy exhibited lower weight loss than the pure epoxy. It is concluded that the effect of an enormous aspect ratio of carbon nanotubes surface area which wider than conventional fillers that react as interface for stress transfer. As increased the contents of carbon nanotubes, the weight loss from the wear test was reduced. And the surface modified carbon nanotubes show better tribological property than as produced carbon nanotubes. It is due that a surface modification of carbon nanotubes increases the interfacial bonding between carbon nanotubes and epoxy matrix through chemical bonding. Changes in worn surface morphology are also observed by optical microscope and SEM for investigating wear behaviors. Carbon nanotubes in the epoxy matrix near the surface are exposed, because it becomes the lubricating working film on the worn surface. It reduces the friction and results in the lower surface roughness morphology in the epoxy matrix as increasing the contents of the carbon nanotubes.

• Structural Engineering and Mechanics
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• v.33 no.2
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• pp.193-213
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• 2009

In this paper structural analysis of nonhomogeneous nanotubes has been carried out using nonlocal elasticity theory. Governing differential equations of nonhomogeneous nanotubes are derived. Nanotubes include both single wall nanotube (SWNT) and double wall nanotube (DWNT). Nonlocal theory of elasticity has been employed to include the scale effect of the nanotubes. Nonlocal parameter, elastic modulus, density and diameter of the cross section are assumed to be functions of spatial coordinates. General Differential Quadrature (GDQ) method has been employed to solve the governing differential equations of the nanotubes. Various boundary conditions have been applied to the nanotubes. Present results considering nonlocal theory are in good agreement with the results available in the literature. Effect of variation of various geometrical and material parameters on the structural response of the nonhomogeneous nanotubes has been investigated. Present results of the nonhomogeneous nanotubes are useful in the design of the nanotubes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.454-459
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• 2003

We investigate the structure and properties of SiC (Silicon Carbide) nanotubes using molecular dynamics simulation based on the Tersoff bond-order potential. For small diameter tubes, the Si-C bond distance of SiC nanotubes decreases as the nanotube diameter is decreased, due to curvature of the nanotube surface. We find that Young's modulus of SiC nanotubes is somewhat smaller than that of the other nanotubes considered so far. However, Young's modulus for SiC nanotubes is larger than that of ${\beta}$-SiC and almost equal to the experimental value for SiC nanorod and SiC whisker. The strain energy of the SiC nanotubes is also lower than that of the other nanotubes. The lower strain energy of SiC nanotubes raises the possibility of synthesis of SiC nanotubes.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.897-899
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• 2007

Transparent electrodes for a flexible display based on the liquid crystal (LC) were formed by carbon nanotubes (CNTs) on polyethylene terephthalate (PET) substrates. The thin multi wall carbon nanotubes (t-MWNTs) networks for electrodes were obtained by filtration- transfer method from welldispersed CNTs solution.

• Proceedings of the Korean Vacuum Society Conference
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• 2002.06a
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• pp.111-111
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• 2002

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.95-95
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• 2003

• Proceedings of the Korean Vacuum Society Conference
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• 2002.06a
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• pp.115-115
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• 2002

• Proceedings of the Korean Vacuum Society Conference
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• 2002.06a
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• pp.130-130
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• 2002

• Proceedings of the Korean Vacuum Society Conference
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• 2004.02a
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• pp.111-111
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• 2004