- Deaggregation and Ultradispersion of Detonation Nanodiamonds in Polar Solvent Using Physicochemical Treatments
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Changkyu Kim, Gyoung-Ja Lee, Changkyu Rhee
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J Korean Powder Metall Inst. 2013;20(6):479-486.
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DOI: https://doi.org/10.4150/KPMI.2013.20.6.479
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- In the present work, physicochemical treatments were introduced for de-aggregation and stable dispersion of detonation nanodiamonds (DND) in polar solvents. The DNDs in water exhibited a particle size of 138 nm and high dispersion stability without particular treatment. However, the DNDs in ethanol were severely aggregated to several micrometers in size and showed poor dispersion stability with time. To break down aggregates of DNDs and enhance the dispersion stability of them in ethanol, mechanical force and chemical surfactant were introduced as functions of zirconia ball size, kind of surfactant and amount of surfactant added. From the analyses of average particle size and Turbiscan results, it was suggested that the size of DNDs in ethanol can be reduced by only mechanical force; however, the DNDs were re-aggregated due to high surface activity. The long-term dispersion stability can be achieved by applying mechanical force to break down the aggregates of DNDs and by preventing re-aggregation of them using proper surfactant.
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Citations
Citations to this article as recorded by  - Material Removal Model for Lapping Process Based on Spiral Groove Density
Taekyung Lee, Haedo Jeong, Sangjik Lee, Hanchul Cho, Doyeon Kim, Hyoungjae Kim
Applied Sciences.2021; 11(9): 3950. CrossRef - Fundamental aspects and recent developments in electropolishing
Wei Han, Fengzhou Fang
International Journal of Machine Tools and Manufacture.2019; 139: 1. CrossRef - Effect of added ethanol in ethylene glycol–NaCl electrolyte on titanium electropolishing
Donghyun Kim, Kyungsik Son, Dahye Sung, Yonghwan Kim, Wonsub Chung
Corrosion Science.2015; 98: 494. CrossRef
- Size Control of Bismuth Nanoparticles by Changes in Carrier-Gas Flow Rate and Chamber Pressure of Gas Condensation Apparatus
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Gyoung-Ja Lee, Chang-Kyu Kim, Min-Ku Lee, Chang-Kyu Rhee
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J Korean Powder Metall Inst. 2010;17(5):379-384.
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DOI: https://doi.org/10.4150/KPMI.2010.17.5.379
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- 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
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Chang-Kyu Kim, Gyoung-Ja Lee, Chang-Kyu Rhee
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J Korean Powder Metall Inst. 2010;17(4):270-275.
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DOI: https://doi.org/10.4150/KPMI.2010.17.4.270
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173
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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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Citations
Citations to this article as recorded by - 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
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Chang-Kyu Kim, Gyoung-Ja Lee, Chang-Kyu Rhee
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J Korean Powder Metall Inst. 2010;17(4):276-280.
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DOI: https://doi.org/10.4150/KPMI.2010.17.4.276
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207
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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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Citations
Citations to this article as recorded by - 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
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Chang-Kyu Kim, Gyoung-Ja Lee, Young-Rang Uhm, Min-Ku Lee, Chang-Kyu Rhee
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J Korean Powder Metall Inst. 2009;16(3):180-184.
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DOI: https://doi.org/10.4150/KPMI.2009.16.3.180
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- 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.
- Determination of Fractal Dimension and Surface Characterization of Metal Nano-powder Using Nitrogen Gas Adsorption Method
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Gyoung-Ja Lee, Young-Rang Uhm, Chang-Kyu Rhee
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J Korean Powder Metall Inst. 2007;14(6):391-398.
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DOI: https://doi.org/10.4150/KPMI.2007.14.6.391
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160
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- The surface roughness of Al, Ag and Ni nano-powders which were prepared by pulsed wire evaporation method was quantified based upon the fractal theory. The surface fractal dimensions of metal nano-powders were determined from the linear relationship between In V/V_mono and Inln (Po/P) using multi-layer gas adsorption theory. Moreover, the fractal surface image was realized by computer simulation. The relationship between preparation condition and surface characteristics of metal nano-powders was discussed in detail.
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Citations
Citations to this article as recorded by - Electrophoretic deposition of Ni nanoparticles from suspension on to a Ni plate
Keun-Yong Park, Young Rang Uhm, Kwang Jae Son, Deok-Yong Park
Research on Chemical Intermediates.2015; 41(9): 6721. CrossRef
- Self-repairing Technology by Electrophoresis of Ni Nano-Particles for Heat Exchanger Tubes
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Gyoung-Ja Lee, Min-Ku Lee, Chang-Kyu Rhee
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J Korean Powder Metall Inst. 2007;14(4):238-244.
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DOI: https://doi.org/10.4150/KPMI.2007.14.4.238
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144
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- The electrophoretic deposition process of Ni nano-particles in organic suspension was employed for self-repairing of heat exchanger tubes. For this purpose, Ni nano-particles prepared by levitational gas condensation method were dispersed into the solution of ethanol with the addition of dispersant Hypermer KD2. For electrophoretic deposition of Ni nano-particles on the Ni alloy specimen, constant electric fields of 20 and 100 V cm-1 were applied to the specimen in Ni-dispersed solution. It was found that as electrophoretic deposition proceeds, the size of the pit or crack remarkably decreased due to the agglomeration of Ni nano-particles at the pit or crack. This strongly suggests that the electrophoretic mobility of the charged particles is larger for the damaged part with a higher current value rather than outer surfaces with a lower current value.
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Citations
Citations to this article as recorded by - Electrophoretic deposition of Ni nanoparticles from suspension on to a Ni plate
Keun-Yong Park, Young Rang Uhm, Kwang Jae Son, Deok-Yong Park
Research on Chemical Intermediates.2015; 41(9): 6721. CrossRef
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