• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.567-568
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• 2006

To investigate the recycle possibility of slurry for the oxide-chemical mechanical polishing (oxide-CMP) application, three kinds of retreated methods were introduced as follows: First, the effects on the addition of silica abrasives and the diluted silica slurry (DSS) on CMP performances were investigated. Second, the characteristics of mixed abrasive slurry (MAS) using non-annealed and annealed alumina ($Al_2O_3$) powder as an abrasive added within DSS were evaluated to achieve the improvement of removal rates (RRs) and within-wafer non-uniformity (WIWNU%). Third, the oxide-CMP wastewater was examined in order to evaluate the possible ways of reusing it. And then, we have discussed the CMP characteristics of silica slurry retreated by mixing of original slurry and used slurry (MOS).

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.73-77
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• 2019

Isothermal (vapor + liquid) equilibrium data measurements were undertaken for the binary mixtures of (propylene oxide + 1-pentanol) system at three different temperatures (303.15, 318.15, and 333.15) K. The Peng-Robinson-Stryjek-Vera equation of state (PRSV EOS) was used to correlate the experimental data. The van der Waals one-fluid mixing rule was used for the vapor phase and the Wong-Sandler mixing rule, which incorporates the non-random two liquid (NRTL) model, the universal quasi-chemical (UNIQUAC) model and the Wilson model, was used for the liquid phase. The experimental data were in good agreement with the correlation results.

• Journal of the Korean institute of surface engineering
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• v.55 no.2
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• pp.84-90
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• 2022

With the growing interest in energy storage and conversion systems including secondary batteries, capacitors, and water electrolysis, various electrode materials are being developed to improve the energy efficiency. Among them, graphene is regarded as one of the promising candidates owing to its exceptional properties - large surface area, and excellent electrical conductivity. Herein, we report a facile one-step electrochemical approach to synthesize exfoliated graphene/Fe oxide compound. The effect of experimental conditions - the types of applied voltage, kinds of counter electrodes, acidity of electrolyte on the synthesis of graphene/Fe oxide compound is investigated.

• Journal of the Korean institute of surface engineering
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• v.49 no.6
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• pp.521-529
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• 2016

In this study, titanium nanotubes, prepared by anodization method, showing high surface and strong chemical stability in acidic and basic media, have been employed for the application to the electrodes for water splitting in KOH solution. Due to its high polarization resistance of $TiO_2$ itself, proper catalysts are essentially required to reduce overpotentials for water oxidation and reduction. Most of academic literature showed noble metal catalysts for foreign dopants in $TiO_2$ electrodes. From commercialization point of view, screening of low-cost catalyst is important. Herein, we propose molybdenum oxide as low-cost catalysts among various catalysts tested in the experiments, which exhibits the highest performance for hydrogen evolution reaction in highly alkaline solution. We showed that molybdenum oxide doped electrode can be operated in extreme acidic and basic conditions as well.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.61-66
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• 2022

This study is to increase the surface area and maximize the effect of the catalyst by coating a nanometersized metal catalyst material on the anode layer using atomic layer deposition (ALD) technology. ALD process is known to produce uniform films with well-controlled thickness at the atomic level on substrates. We measured the performance by coating metals (Ni) on Ni/YSZ, which is the most widely known anode material for solid oxide fuel cells. ALD coatings began to show a decrease in cell performance over 3 nm coatings.

• Journal of the Korean Ceramic Society
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• v.11 no.1
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• pp.3-9
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• 1974

The role of added metal oxide in the adherence mechanism of low melting glass to several metal plates such as oxygen free high conducting copper, low carbon steel, chrominum galvanized on copper, and stainless steel was investigated. The metal oxide which added to glass were cupric oxide, ferric oxide, chromic oxide, and stainless steel oxide. The glass to that various metla oxide were added, sealed with several metal plates in the electric furnace at $650^{\circ}C$ for 5 minutes. The results as follows; 1) The interfacial reaction was promoted and strong chemical bonding with glass and metals by which the surface energy was decreased showed excellent sealing by addition of metal oxide. 2) When the interfacial reaction of glass and metals was promoted by addition of metal oxide found out that various adhernece mechanism were related to the sealing. 3) When the amount of metal oxide addition was 3-5% the excellent sealing was achieved.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1743-1748
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• 2005

This work presents that carbon dioxide, which is a main contributor to the global warming effect, could be utilized as a selective oxidant in the oxidative dehydrogenation of ethylbenzene. The dehydrogenation of ethylbenzene over alumina-supported vanadium-antimony oxide catalyst has been studied under different atmospheres such as inert nitrogen, steam, oxygen or carbon dioxide as diluent or oxidant. Among them, the addition of carbon dioxide gave the highest styrene yield (up to 82%) and styrene selectivity (up to 97%) along with stable activity. Carbon dioxide could play a beneficial role of a selective oxidant in the improvement of the catalytic behavior through the oxidative pathway.

• Journal of the Korean Electrochemical Society
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• v.12 no.1
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• pp.1-10
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• 2009

This article reviewed transport behaviours of electroactive species in ionic compounds, focusing on chemical diffusion of Li through the transition metal oxide in a current flowing condition. For this purpose, a distinction has been first briefly made between migration and diffusion with respect to current, driving force and charge of electroactive species considered. Then, the equations for chemical diffusion are derived theoretically in open-circuit and current flowing conditions. Finally, the experimental methods such as ac impedance spectroscopy and current (potential) transient techniques are described in details for characterising chemical diffusion. In addition, the role of the thermodynamic enhancement factor in chemical diffusion is discussed.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.665-668
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• 2008

Propylene epoxidation by $H_2O_2$ (30% aqueous) as oxidant was studied in a semi-batch reactor using Ti-MCM-22 catalyst: Effects of reaction temperature, pressure, catalyst loading, solvent, and $H_2O_2$ concentration on $H_2O_2$ conversion (limiting reagent) were investigated. Product inhibition by propylene oxide was confirmed. Ti-MCM-22 maintained virtually the same catalytic performance over the 5 repeated cycles.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2474-2479
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• 2018

Plasma-enhanced atomic layer deposition (PEALD) is well-known for fabricating conformal and uniform films with a well-controlled thickness at the atomic level over any type of supporting substrate. We prepared nickel oxide (NiO) thin films via PEALD using bis(ethylcyclopentadienyl)-nickel ($Ni(EtCp)_2$) and $O_2$ plasma. To optimize the PEALD process, the effects of parameters such as the precursor pulsing time, purging time, $O_2$ plasma exposure time, and power were examined. The optimal PEALD process has a wide deposition-temperature range of $100-325^{\circ}C$ and a growth rate of $0.037{\pm}0.002nm$ per cycle. The NiO films deposited on a silicon substrate with a high aspect ratio exhibited excellent conformality and high linearity with respect to the number of PEALD cycles, without nucleation delay.