Journal of Powder Materials

Chang-Kyu Kim

4 Articles

Size Control of Bismuth Nanoparticles by Changes in Carrier-Gas Flow Rate and Chamber Pressure of Gas Condensation Apparatus: Gyoung-Ja Lee, Chang-Kyu Kim, Min-Ku Lee, Chang-Kyu Rhee; J Korean Powder Metall Inst. 2010;17(5):379-384.; DOI: https://doi.org/10.4150/KPMI.2010.17.5.379

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Abstract PDF: In the present work, bismuth nanopowders with various particle size distributions were synthesized by controlling argon (Ar) gas flow rate and chamber pressure of a gas condensation (GC) apparatus. From the analyses of transmission electron microscopy (TEM) images and nitrogen gas adsorption results, it was found that as Ar gas flow rate increased, the specific surface area of bismuth increased and the average particles size decreased. On the other hand, as the chamber pressure increased, the specific surface area of bismuth decreased and the average particles size increased. The optimum gas flow rate and chamber pressure for the maximized electrochemical active surface area were determined to be 8 L/min and 50 torr, respectively. The bismuth nanopowders synthesized at the above condition exhibit 13.47 m2g-1 of specific surface area and 45.6 nm of average particles diameter.

Synthesis and Characterization of Cu Nanofluid Prepared by Pulsed Wire Evaporation Method: Chang-Kyu Kim, Gyoung-Ja Lee, Chang-Kyu Rhee; J Korean Powder Metall Inst. 2010;17(4):270-275.; DOI: https://doi.org/10.4150/KPMI.2010.17.4.270

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Ethylene glycol-based Cu nanofluids were prepared by pulsed wire evaporation (PWE) method. The structural properties of Cu nanoparticles were studied by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The average diameter and Brunauer Emmett Teller (BET) surface area of Cu nanoparticles were about 100 nm and 7.46;m2/g, respectively. The thermal conductivity and viscosity of copper nanofluid were measured as functions of Cu concentration and temperature. As the volume fraction of Cu nanoparticles increased, both the enhanced ratios of thermal conductivity and viscosity of Cu nanofluids increased. As the temperature increased, the enhanced ratio of thermal conductivity increased, but that ratio of viscosity decreased.

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Characterization of Classification of Synthesized Ni Nanopowders by Pulsed Wire Evaporation Method
Joong-Hark Park, Geon-Hong Kim, Dong-Jin Lee, Soon-Jik Hong
Journal of Korean Powder Metallurgy Institute.2017; 24(5): 389. CrossRef
Effect of Electrical Parameters and Surrounding Gas on the Electroexplosive Tungsten Nanopowders Characteristics
Young-Soon Kwon, Jin-Chun Kim, Alexander P. Ilyin, Olga B. Nazarenko, Dmitry V. Tikhonov
Journal of Korean Powder Metallurgy Institute.2012; 19(1): 49. CrossRef
Thermal conductivity enhancement of ZnO nanofluid using a one-step physical method
Gyoung-Ja Lee, Chang Kyu Kim, Min Ku Lee, Chang Kyu Rhee, Seokwon Kim, Chongyoup Kim
Thermochimica Acta.2012; 542: 24. CrossRef

A Study on Thermal Properties of Ethylene Glycol Containing Copper Oxide Nanoparticles: Chang-Kyu Kim, Gyoung-Ja Lee, Chang-Kyu Rhee; J Korean Powder Metall Inst. 2010;17(4):276-280.; DOI: https://doi.org/10.4150/KPMI.2010.17.4.276

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4 Citations

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In the present work, ethylene glycol-based (EG) copper oxide nanofluids were synthesized by pulsed wire evaporation method. In order to explode the pure copper wire, high voltage of 23 kV was applied to the both ends of wire and argon/oxygen gas mixture was used as reactant gas. EG-based copper oxide nanofluids with different volume fraction were prepared by controlling explosion number of copper wire. From the transmission electron microscope (TEM) image, it was found that the copper oxide nanoparticles exhibited an average diameter about 100 nm with the oxide layer of 2~3 nm. The synthesized copper oxide consists of CuO/Cu_2O phases and the Brunauer Emmett Teller (BET) surface area was estimated to be 6.86;m2;g-1. From the analyses of thermal properties, it is suggested that viscosity and thermal conductivity of EG-based copper oxide nanofluids do not show temperature-dependent behavior over the range of 20 to 90°C. On the other hand, the viscosity and thermal conductivity of EG-based copper oxide nanofluids increase with volume fraction due to the active Brownian motion of the nanoparticles, i.e., nanoconvection.

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Thermal conductivity enhancement of ZnO nanofluid using a one-step physical method
Gyoung-Ja Lee, Chang Kyu Kim, Min Ku Lee, Chang Kyu Rhee, Seokwon Kim, Chongyoup Kim
Thermochimica Acta.2012; 542: 24. CrossRef
Fabrication of Ni-free Fe-based Alloy Nano Powder by Pulsed Wire Evaporation in Liquid: Part I. Effect of Wire Diameter and Applied Voltage
Ho-Jin Ryu, Yong-Heui Lee, Kwang-Ug Son, Young-Min Kong, Jin-Chun Kim, Byoung-Kee Kim, Jung-Yeul Yun
Journal of Korean Powder Metallurgy Institute.2011; 18(2): 105. CrossRef
Fabrication of Ni-free Fe-based Alloy Nano Powder by Pulsed Wire Evaporation in Liquid: Part 2. Effect of Solvent and Comparison of Fabricated Powder owing to Fabrication Method
Ho-Jin Ryu, Yong-Heui Lee, Kwang-Ug Son, Young-Min Kong, Jin-Chun Kim, Byoung-Kee Kim, Jung-Yeul Yun
Journal of Korean Powder Metallurgy Institute.2011; 18(2): 112. CrossRef
Synthesis and Characterization of (AgSbTe2)15(GeTe)85Thermoelectric Powder by Gas Atomization Process
Hyo-Seob Kim, Jin-Kyu Lee, Jar-Myung Koo, Byong-Sun Chun, Soon-Jik Hong
Journal of Korean Powder Metallurgy Institute.2011; 18(5): 449. CrossRef

Response Characteristics of Electrochemical Non-enzyme Immunosensor using Fe₃O₄ Nanoparticle: Chang-Kyu Kim, Gyoung-Ja Lee, Young-Rang Uhm, Min-Ku Lee, Chang-Kyu Rhee; J Korean Powder Metall Inst. 2009;16(3):180-184.; DOI: https://doi.org/10.4150/KPMI.2009.16.3.180

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Abstract PDF: In this paper, the electrochemical non-enzyme immunosensor has been developed for the determination of salmonella antigen, using inverse voltammetry. For the estimation of salmonella antigen concentration, the Fe_3O_4 nanoparticles synthesized by microemulsion method were conjugated with salmonella antigen. Then, the immunocomplex between antibody immobilized on the transducer surface and antigen containing a magnetic nanoparticles was formed. From the linear relationship between the reduction peak current of Fe(III) and salmonella antigen concentration, it is suggested that the electrochemical non-enzyme biosensor is applicable to detect salmonella antigen in the concentration range of 101-105 CFU/ml.

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