• 한국분말재료학회지
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• 제8권3호
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• pp.186-191
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• 2001

Several fabrication processes, corresponding nanostructural features and multifunctionality as well has been investigated for oxide ceramic based nanocomposites with metal nanodispersion (i.e., ceramic/metal nanocomposites). Transition metal (Ni, Co, etc) dispersed alumina and zirconia based nanocomposites have been synthesized by reducing and hot-press sintering of ceramic and metal oxide mixtures prepared by several method. Improved fracture strength (1.1 and 1.9 GPa for $Al_2O_3/Ni$ and $ZrO_2/Ni$ nanocomposites, respectively) of these composites have been achieved according to their nanostructures. In addition, ferromagnetic characteristic has been kept. The variation of magnetization with an applied stress has found to be more sensitive as smaller as the magnetic metal dispersion is. This result thus suggests the possibility of fracture and/or stress sensing of the composites by simple magnetic measurement.

• The Korean Journal of Ceramics
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• 제5권4호
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• pp.395-399
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• 1999

MgO/metal nanocomposite powder mixtures were prepared by solution chemical processes to obtain suitable structure for ceramic/metal nanocomposites. Nickel or cobalt nitrate, as a source of metal dispersion, was dissolved into alcohol and mixed with magnesia powder. After calcined in air, these powders were reduced by hydrogen. Densified nanocomposites were successively obtained by Pulse Electric Current Sintering (PECS) process. The dispersed metal partical size depended on temperature and time in calcination and reduction processes. The phase analyses in the synthesized powders as a functioni of temperature were tracked using a dynamic high temperature X-ray diffractioni (HTXRD) system. Phase and crystallite size analyses were done using X-ray diffractioni and TEM. The MgO/metal nanocomposites were successfully fabricated, and ferromagnetic responses with enhanced coercive force were also investigated for these composites.

• 한국재료학회지
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• 제15권8호
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• pp.503-507
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• 2005

Microstructure and wear behavior of A1203-based nanocomposites with Cu and Ni-Co dispersions were investigated. $Al_2O_3/Cu$ and $Al_2O_3/Ni-Co$ nanocomposites were fabricated by hydrogen reduction and sintering method using metal oxide and metal nitrates. The nanocomposites showed increased mechanical properties compared with monolithic $Al_2O_3$. In particular, high toughness and hardness were measured for the $Al_2O_3/Ni-Co$ nanocomposite consolidated by spark plasma sintering. A minimum value of wear coefficient comparable to the monolithic $Al_2O_3$ was obtained for $Al_2O_3/Ni-Co$ nanocomposite. Wear behavior is discussed in terms of microstructure and mechanical properties of nanocomposites

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.401-406
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• 2014

Metal-containing carbon nanocomposites have shown significance promise in the area of energy storage, heterogeneous catalysis and material science because of their morphology and combined properties. Phosphorus-doped carbon nanocomposites with gold nanoparticles were developed by applying a simple impregnation method and metal deposition technique. Gold-phosphorus supported carbon nanocomposites with two sized (25 and 170 nm) were prepared from economical petroleum pitch residue as the carbon source using an advanced silica template method. These nanocomposites will lead to the novel applications in the field of material science with the combined properties of gold, phosphorus and carbon. The newly prepared gold phosphorus supported carbon nanocomposites were fully characterized using a range of different physico-chemical techniques.

• 소성∙가공
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• 제15권5호
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• pp.360-365
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• 2006

Carbon nanotubes (CNTs) have been the subject of intensive studies for applications in the fields of nano technologies in recent years due to their superior mechanical, electric, optical and electronic properties. Because of their exceptionally small diameters (${\appros}\;several\;nm$) as well as their high Young's modulus (${\appros}1\;TPa$), tensile strength (${\appros}\;200\;GPa$) and high elongation (10-30%) in addition to a high chemical stability, CNTs are attractive reinforcement materials for light weight and high strength metal matrix composites. Although extensive researches have been performed on the electrical, mechanical and functional properties of CNTs, there are not many successful results on the mechanical properties of CNT dispersed nanocomposites. In this paper, we applied equal channel angular pressing for consolidation of CNT/Cu powder mixtures. We also investigated the hardness and microstructures of CNT/Cu nanocomposites used experimental for metal matrix composites.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.61-61
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• 2008

Nanocomposites of metal (gold and silver) nanoparticles and multi-walled carbon nanotubes (MWNTs) were prepared with the assistance of various stabilizers for metals and MWNTs. Especially common surfactants such as poly(4-vinylpyridine) (PVP), sodium dodecyl sulfate (SDS), poly(sodium 4-styrene sulfonate) (PSS), and poly(diallyldimethylammonium) chloride (PDDA) were used for the sample preparation. Metal/MWNT nanocomposites were structurally characterized in by transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), UV/Vis spectroscopy. In addition, the electrical properties of the nanocomposites were studied by cyclic voltammetry (CV).

• 공업화학
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• 제26권5호
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• pp.521-525
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• 2015

2차원 구조와 우수한 물성을 지닌 그래핀 기반의 전극 재료들은 슈퍼커패시터에 많이 응용되어 왔다. 특히 3차원 구조의 그래핀 소재들은 전극 제조에 매우 중요한데 이는 3차원 구조가 넓은 표면적, 효과적이고 빠른 전기 및 이온 전달, 우수한 기계적 물성을 제공하기 때문이다. 최근에는 3차원 하이브리드 구조를 가지는 그래핀/금속 산화물 재료들이 슈퍼커패시터의 에너지와 파워 밀도를 동시에 증가시키고자 개발되어 왔다. 본 논문은 그래핀과 금속 산화물로 이루어진 3차원 나노복합체의 최근 연구 경향을 논하고자 한다. 3차원 나노복합체의 제조와 구조 및 이를 이용한 슈 퍼커패시터의 응용을 다룬다.

• Advances in materials Research
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• 제6권2호
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• pp.129-153
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• 2017

Platinum is a transition metal that is very resistant to corrosion. It is used as catalyst for converting methyl alcohol to formaldehyde, as catalytic converter in cars, for hydrocracking of heavy oils, in Fuel Cell devices etc. Moreover, Platinum compounds are important ingredient for cancer chemotherapy drugs. The nano forms of Platinum due to its unique physico-chemical properties that are not found in its bulk counterpart, has been found to be of great importance in electronics, optoelectronics, enzyme immobilization etc. The stability of Platinum nanoparticles has supported its use for the development of efficient and durable proton exchange membrane Fuel Cells. The present review concentrates on the use of Platinum conjugated with various metal or compounds, to fabricate nanocomposites, to enhance the efficiency of Platinum nanoparticles. The recent advances in the synthesis methods of different Platinum-based nanocomposites and their applications in Fuel Cell, sensors, bioimaging, light emitting diode, dye sensitized solar cell, hydrogen generation and in biosystems has also been discussed.

• 한국분말재료학회지
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• 제18권2호
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• pp.181-187
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• 2011

PVDF was used as a polymeric matrix material in this work. Nickel powders with average particles size of 200 nm or 72 nm were used as fillers. PVDF/metal submicro- and nanocomposites were prepared by means of a mixing in twin screw extruder and planetary ball mill, respectively. All samples were prepared by hot pressing method. Their electrical, thermal and morphological properties were examined by dielectric spectroscopy, DSC, FTIR, XRD, optical microscopy and scanning electron microscopy. It was found that all properties of composites were strongly modified depending on the content of metal powders and filler particles size. Particularly, specific volume resistivity of PVDF/Ni composite with 0.2 wt.% of Ni was increased by factor of 1.5~4.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.28-51
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• 2018

Graphitic carbon nitride ($g-C_3N_4$) as a fascinating visible light active semiconductor photocatalyst has medium band gap, non-toxic nature, stable chemical structure and high thermal stability. Recently, intensive researches are focused on photocatalytic activity of $g-C_3N_4$ for wastewater treatment. This review demonstrates latest progress in fabrication of graphitic carbon nitride $C_3N_4$ incorporated nanocomposite to explore photocatalytic ability for water purification. The $g-C_3N_4$-based nanocomposites were categorized as $g-C_3N_4$ metal-free nanocomposite, noble metals/$g-C_3N_4$ heterojunction, non-metal doped $g-C_3N_4$, transition and post transition metal based $g-C_3N_4$ nanocomposite. Apart from fabrication methods, we emphasized on elaborating the mechanism of activity enhancement during photocatalytic process.