• Journal of the Society of Disaster Information
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• v.12 no.4
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• pp.373-380
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• 2016

In order to develop composite fiber panels that can maximize the protection and blast resistance of the existing structures by improving lightweight, high-strength and fireproof performances of the single layer material of precast panels, the basic properties of the inner and outer covers that are mixed with aramid fibers (AF) and polyester fibers (PF) were evaluated in this study. Also, a basic study was performed on the performance of composite fiber panels by testing Nano-sized composite materials that are lightweight and excellent in fire resistance for their compressive strength, bending strength and tensile strength.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.121-128
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• 2005

The research on electromagnetic shielding has been advanced for military applications as well as for commercial products. Utilizing the reflective properties and absorptive properties of shielding material, the replied signal measured at the rear surface or at the signal source can be minimized. The shielding effect was obtained from materials having special absorptive properties and structural characteristics such as stacking sequence. Recently researchers studied the electromagnetic properties of nano size particles. In this research {glass fiber}/{epoxy}/{nano particle} composites(GFR-Nano composites) was fabricated using various nano particles, and their properties in electromagnetic shielding were compared. For the visual observation of the nano composite materials, SEM(Scanning Electron Microscope) and TEM(Transmission Electron Microscope) were used. For the measurement of electromagnetic shielding, HP8719ES S-parameter Vector Network Analyser System was used on the frequency range of 8 GHz${\~}$12GHz. Among the nano particles, carbon black and Multi-Walled Carbon Nano-Tube (MWCNT) revealed outstanding electromagnetic shielding. Although silver nano particles (flake and powder) were expected to have effective electromagnetic shielding due to their excellent electric conductivities, test results showed little shielding characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04c
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• pp.73-74
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• 2008

In this paper, we have investigated dispersibility, volume resistivity of nano-composite by solution mixing method. Dispersibility measured by FE-SEM(Field Emission Scanning Electron Microscope. And volume resistivity measured by ASTM D991. To expect interaction used dual filler system. But, dual filler system had influence on polymer complex. So, polymer chain mobility doesn't resist.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.801-804
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• 2002

Electrochemical capacitors are becoming attractive energy storage systems particularly for applications involving high power requirements such as hybrid systems consisting of batteries and electrochemical capacitors for electric vehicle propulsion. Both of amorphous cobalt oxide and manganese dioxide were prepared by sol-gel process reported in our previous work. Nanostructured supramolecular oligomer of 1,5-diaminoanthraquinone(DAAQ) coated metal oxides were successfully prepared by electrochemical oxidation from an acidic non-aqueous medium. We established process parameters of the technique for the formation of nano-structured materials. Furthermore, improved the capacitive properties of the nano structured metal oxide electrodes using controlled solution chemistry. $CoO_2$ and $MnO_2$-based composite electrode showed relatively good electrochemical behaviors in acidic electrolyte system with respect to specific capacity and scan rate dependency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.210-211
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• 2006

This study presents the technology and application of hybrid insulation film for electric magnet wire. In order to make the high efficient motor with high space factor, it is necessary to develop a self-lubrication heat-resistant insulation film that can be used when the space factor 70% or more. A key to achieving high windability is to increase the lubricity and bonding strength of vanish, which for a magnet wire generally determines the mechanical scratches characteristics. Effective ways to reduce scratches include improving insulation film prepared by organic and inorganic hybrid synthesis methods.

• Journal of Powder Materials
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• v.22 no.1
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• pp.15-20
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• 2015

The composite of porous silicon (Si) and amorphous carbon (C) is prepared by pyrolysis of a nano-porous Si + pitch mixture. The nano-porous Si is prepared by mechanical milling of magnesium powder with silicon monoxide (SiO) followed by removal of MgO with hydrochloric acid (etching process). The Brunauer-Emmett-Teller (BET) surface area of porous Si ($64.52m^2g^{-1}$) is much higher than that before etching Si/MgO ($4.28m^2g^{-1}$) which indicates pores are formed in Si after the etching process. Cycling stability is examined for the nano-porous Si + C composite and the result is compared with the composite of nonporous Si + C. The capacity retention of the former composite is 59.6% after 50 charge/discharge cycles while the latter shows only 28.0%. The pores of Si formed after the etching process is believed to accommodate large volumetric change of Si during charging and discharging process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.189-192
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• 2004

To improvement life-time of the organic light emitting diodes(OLEDs). We investigate the inorganic composite film based on MgO and $SiO_2$ to protect from the moisture and oxygen. The inorganic composite films are added the base materials to the co-operate materials using the mixed process and it is deposited on plastic substrate by e-beam evaporator. In order to analyze as kinds of inorganic materials, Water Vapor method of Transmission Rate (WVTR) and Oxygen Transmission Rate (OTR) are measured by Permatran equipment(MOCON Corp.). For comparison. an MgD- and $SiO_2$-based composite film has lower values of WVTR and OTR than inorganic composite/compound films of ones. The results obtained here shows that this film is suitable for passivation layer to extend the life-time of OLEDs.

• Journal of Welding and Joining
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• v.32 no.3
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• pp.68-73
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• 2014

Among through silicon via (TSV) technologies, for replacing Cu filling method, the method of molten solder filling has been proposed to reduce filling cost and filling time. However, because Sn alloy which has a high coefficient of thermal expansion (CTE) than Cu, CTE mismatch between Si and molten solder induced higher thermal stress than Cu filling method. This thermal stress can deteriorate reliability of TSV by forming defects like void, crack and so on. Therefore, we fabricated SiC composite filling material which had a low CTE for reducing thermal stress in TSV. To add SiC nano particles to molten solder, ball-typed SiC clusters, which were formed with Sn powders and SiC nano particles by ball mill process, put into molten Sn and then, nano particle-dispersed SiC composite filling material was produced. In the case of 1 wt.% of SiC particle, the CTE showed a lowest value which was a $14.8ppm/^{\circ}C$ and this value was lower than CTE of Cu. Up to 1 wt.% of SiC particle, Young's modulus increased as wt.% of SiC particle increased. And also, we observed cross-sectioned TSV which was filled with 1 wt.% of SiC particle and we confirmed a possibility of SiC composite material as a TSV filling material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.7-7
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• 2010

Indium tin oxide (ITO) - SWNT nano crystalline composites was synthesized at low temperature(${\sim}250^{\circ}C$)using Nano Cluster Deposition technique by Metal Orhoganic Chemical Vapor Deposition method. XRD patterns of ITO- SWNT composite shows pure cubic phases without any secondary phase. I-V measurement gives resistance of 12 ohms for Sn doped (3 wt %) indium oxide-SWNT composites. The electrical conductivity of the nano composites is significantly enhanced compared to the SWNT.

• Korean Journal of Materials Research
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• v.33 no.4
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• pp.151-158
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• 2023

In this study, a new type of composite material combined with carbonyl iron, a relatively strong ferromagnetic material, was prepared to overcome the current application limitations of Prussian blue, which is effective in removing radioactive cesium. The surface of the prepared composite was analyzed using SEM and XRD, and it was confirmed that nano-sized Prussian Blue was synthesized on the particle surface. In order to evaluate the cesium removal ability, 0.2 g of the composite prepared for raw cesium aquatic solution at a concentration of 5 ㎍ was added and reacted, resulting in a cesium removal rate of 99.5 %. The complex follows Langmuir's adsorption model and has a maximum adsorption amount (q_e) of 79.3 mg/g. The Central Composite Design (CCD) of the Response Surface Method (RSM) was used to derive the optimal application conditions of the prepared composite. The optimal application conditions achieved using Response optimization appeared at a stirring speed of pH 7, 17.6 RPM. The composite manufactured through this research is a material that overcomes the Prussian Blue limit in powder form and is considered to be excellent economically and environmentally when applied to a cesium removal site.