• Proceedings of the Korean Vacuum Society Conference
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• 2005.08a
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• pp.84-84
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• 2005

• Korean Journal of Materials Research
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• v.28 no.6
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• pp.343-348
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• 2018

Recently, the properties of nanostructured materials as advanced engineering materials have received great attention. These properties include fracture toughness and a high degree of hardness. To hinder grain growth during sintering, it is necessary to fabricate nanostructured materials. In this respect, a high-frequency induction-heated sintering method has been presented as an effective technique for making nanostructured materials at a lower temperature in a very short heating period. Nanopowders of W and $Al_2O_3$ are synthesized from $WO_3$ and Al powders during high-energy ball milling. Highly dense nanostructured $W-Al_2O_3$ composites are made within three minutes by high-frequency induction-heated sintering method and materials are evaluated in terms of hardness, fracture toughness, and microstructure. The hardness and fracture toughness of the composite are $1364kg/mm^2$ and $7.1MPa{\cdot}m^{1/2}$, respectively. Fracture toughness of nanostructured $W-Al_2O_3$ is higher than that of monolithic $Al_2O_3$. The hardness of this composite is higher than that of monolithic W.

• Journal of Powder Materials
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• v.13 no.5 s.58
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• pp.340-350
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• 2006

Nanostructured materials exhibit attractive mechanical properties that are often superior to the performance of their coarse-grained counterparts. However, one major drawback is their low ductility, which limits their potential applications. In this paper, different strategies to obtain both high strength and enhanced ductility in nanostructured materials are reported for Ti-base and Zr-base alloys. The first approach consists of designing an in-situ composite microstructure containing ductile bcc or hop dendrites that are homogeneously dispersed in a nanostructured matrix. The second approach is related to refining the eutectic structure of a Ti-Fe-Sn alloy. For all these materials, the microstructure, mechanical properties, deformation and fracture mechanisms will be discussed.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.11-11
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• 2004

Under the coordination of GKSS a new European project in the field of membrane development started recently. This project focuses on the development of novel nanostructured materials for selective material transport and separation. Two classes of materials will be developed in this project: nanostructured organic/inorganic hybrid materials and functional self-organized supramolecular copolymers.(omitted)

• 한국전자현미경학회:학술대회논문집
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• 2002.11a
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• pp.56-57
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• 2002

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1119-1121
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• 2006

Using a chemical radical we modified the surface property of PET substrates. The chemically treated substrate surface improved dispersion of CNTs on substrate and provides suitable adhesion of CNTs to substrate. In addition, an ink-jet printed patterning technique effectively improved the transparency of transparent conductive CNT composite films.

• Polymer Science and Technology
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• v.23 no.2
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• pp.174-184
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• 2012

• Korean Journal of Materials Research
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• v.30 no.9
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• pp.441-446
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• 2020

Synthesizing nanostructured thin films of oxide semiconductors is a promising approach to fabricate highly efficient photoelectrodes for hydrogen production via photoelectrochemical (PEC) water splitting. In this work, we investigate the feasibility as an efficient photoanode for PEC water oxidation of zinc oxide (ZnO) nanostructured thin films synthesized via a simple method combined with sputtering Zn metallic films on a fluorine-doped tin oxide (FTO) coated glass substrate and subsequent thermal oxidation of the sputtered Zn metallic films in dry air. Characterization of the structural, optical, and PEC properties of the ZnO nanostructured thin film synthesized at varying Zn sputtering powers reveals that we can obtain an optimum ZnO nanostructured thin film as PEC photoanode at a sputtering power of 40 W. The photocurrent density and optimal photocurrent conversion efficiency for the optimum ZnO nanostructured thin film photoanode are found to be 0.1 mA/㎠ and 0.51 %, respectively, at a potential of 0.72 V vs. RHE. Our results illustrate that the ZnO nanostructured thin film has promising potential as an efficient photoanode for PEC water splitting.

• Korean Journal of Materials Research
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• v.24 no.4
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• pp.180-185
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• 2014

The current concern about these materials ($MoSi_2$ and $NbSi_2$) focuses on their low fracture toughness below the ductile-brittle transition temperature. To improve the mechanical properties of these materials, the fabrication of nanostructured and composite materials has been found to be effective. Nanomaterials frequently possess high strength, high hardness, excellent ductility and toughness, and more attention is being paid to their potential application. In this study, nanopowders of Mo, Nb, and Si were fabricated by high-energy ball milling. A dense nanostructured $MoSi_2-NbSi_2$ composite was simultaneously synthesized and sintered within two minutes by high-frequency induction heating method using mechanically activated powders of Mo, Nb, and Si. The high-density $MoSi_2-NbSi_2$ composite was produced under simultaneous application of 80MPa pressure and an induced current. The sintering behavior, mechanical properties, and microstructure of the composite were investigated. The average hardness and fracture toughness values obtained were $1180kg/mm^2$ and $3MPa{\cdot}m^{1/2}$, respectively. These fracture toughness and hardness values of the nanostructured $MoSi_2-NbSi_2$ composite are higher than those of monolithic $MoSi_2$ or $NbSi_2$.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.666-669
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• 2002

Vertically aligned carbon nanotubes (CNTs) have been produced using various type of plasma enhanced chemical vapor deposition (PECVD). Catalysts such as Ni, Co, and Fe are used for growth of CNTs. To explain the effect of catalysts on the growth characteristics of CNTs, carbon species of $C_2H_2$ was observed in different catalysts using optical emission spectroscopy (OES) with theoretical calculation on the surface reaction in different catalysts.