• Industry Promotion Research
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• v.9 no.1
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• pp.31-38
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• 2024

In this study, evaluated the properties of layered silicate-based nanocomposite sensitive film. For the fabrication of nanocomposite materials, we selected organically modified layered silicate materials, specifically Cloisite^® and Bentone^®, which were treated with quaternary ammonium salts. The impedance of the humidity sensors containing organically modified montmorillonite/hectorite clay decreased with increasing relative humidity(RH%). In the case of the Cloisite^® humidity sensor exhibited slightly better impedance linearity and hysteresis compared to the Bentone^® 38 humidity sensor. Additionally the impedance of the sensor with Bentone^® 38 addition was the lowest when compared to the Cloisite^®-modified sensor. Comparing the Cloisite^®-modified sensors individually, we observed different moisture absorption characteristics based on the hydrophilic properties of the organic-treated materials. The response speed of Cloisite^® 93A tended to be slower due to differences in moisture evaporation rates influenced by the hydrophilic organic components. Based on these results, moisture barriers utilizing organically modified layered silicate materials may exhibit slightly lower moisture absorption properties compared to conventional polymer-based moisture barriers. However, their excellent stability, simple processing, and cost-effectiveness make them suitable for humidity sensor applications.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.155.2-155.2
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• 2007

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.829-830
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• 2006

Recent research at Harbin Institute of Technology on the synthesis of nanocrystalline and untrafine grained materials by mechanical alloying/milling is reviewed. Examples of the materials include aluminum alloy, copper alloy, magnesium-based hydrogen storage material, and $Nd_2Fe_{14}B/{\alpha}-Fe$ magnetic nanocomposite. Details of the processes of mechanical alloying and consolidation of the mechanically alloyed nanocrystalline powder materials are presented. The microstructure characteristics and properties of the synthesized materials are addressed.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.86.2-86.2
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• 2008

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.10a
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• pp.25-26
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• 2003

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.133-133
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• 2009

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.261-264
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• 2005

Since the first discovery of carbon nanotube (CNT) in 1991, a window to new technological areas has been opened. One of the emerging applications of CNTs is the reinforcement of composite materials to overcome the performance limits of conventional materials. However, because of the difficulties in distributing CNTs homogeneously in metal or ceramic matrix by means of traditional composite processes, it has been doubted whether CNTs can really reinforce metals or ceramics. In this study, CNT reinforced Cu matrix nanocomposite is fabricated by a novel fabrication process named molecular level mixing process. This process produces CNT/Cu composite powders whereby the CNTs are homogeneously implanted within Cu powders. The CNT/Cu nanocomposite, consolidated by spark plasma sintering of CNT/Cu composite powders, shows to be 3 times higher strength and 2 times higher Young’s modulus than Cu matrix. This extra-ordinary strengthening effect of carbon nanotubes in metal is higher than that of any other reinforcement ever used for metal matrix composites.

• Journal of Powder Materials
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• v.10 no.6
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• pp.443-447
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• 2003

Nano-sized $TiB_2$ was in situ synthesized in copper matrix through self-propagating high temperature synthesis (SHS) with high-energy ball milled Ti-B-Cu elemental mixtures as powder precursors. The size of $TiB_2$ particles in the product of SHS reaction decreases with time of preliminary mechanical treatment ranging from 1 in untreated mixture to 0.1 in mixtures milled for 3 min. Subsequent mechanical treatment of the product of SHS reaction allowed the $TiB_2$ particles to be reduced down to 30-50 nm. Microstructural change of $TiB_2$-Cu nanocomposite during spark plasma sintering (SPS) was also investigated. Under simultaneous action of pressure, temperature and electric current, titanium diboride nanoparticles distributed in copper matrix move, agglomerate and form a interpenetrating phase composite with a fine-grained skeleton.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3671-3676
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• 2013

A series of carbon nanotube, $C_{60}$, and graphene modified $TiO_2$ nanocomposites were prepared by hydrothermal method. X-ray diffraction, $N_2$ adsorption, UV-Vis spectroscopy, photoluminescence, and Electrochemical impedance spectra were used to characterize the prepared composite materials The results reveal that incorporating $TiO_2$ with carbon materials can extend the adsorption edge of all the $TiO_2$-carbon nanocomposites to the visible light region. The photocatalytic activities were tested in the degradation of 2,4,6-trichlorophenol (TCP) under visible light. No obvious difference in essence was observed in structural and optical properties among three series of carbon modified $TiO_2$ nanocomposites. Three series of carbon materials modified $TiO_2$ composites follow the analogous tentative reaction mechanism for TCP degradation. GR modified $TiO_2$ nanocomposite exhibits the strongest interaction and the most effective interfacial charge transfer among three carbon materials, thus shows the highest electron-hole separation rate, leading to the highest photocatalytic activity and stability.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.815-820
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• 2008

The microstructure and mechanical properties of $TiB_2/Si$ nanocomposites based on the Ti-Si-B system, consolidated by spark plasma sintering of mechanically alloyed activated nanopowders, have been characterized. Mechanical Alloying was carried out in a planetary ball mill for 180 min with 350 rev $min^{-1}$. The powders were pressed in vacuum at a pressure of 60 MPa, generating a maximum temperature in the graphite mould of $1400^{\circ}C$. Analysis of the synthesized nanocomposites by SEM, XRD and TEM showed them to consist of $TiB_2$ second phase, sub-micron in size, with no third phase. Composites consolidated from powders mechanically alloyed from an initial elemental powder mix of 0.3 mol Si, 0.7 mol Ti, and 2.0 mol B achieved the best relative density (97%) and bending strength (774 MPa); the highest Vickers hardness of 14.7 GPa was achieved for the 0.1-0.9-2.0 mol starting composition.