• 전기화학회지
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• 제4권4호
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• pp.160-165
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• 2001

황산원자를 포함하는 mercapto화합물은 도금시 전착속도를 증가시키는 첨가제로 알려져 있는데, 이 중 4가지의 mercapto 화합물을 선정하여 농도를 변화시켜가며 Hull cell test, Haring-Blum cell test, cathodic polarization, EQCM(Electrochemical Quartz Crystal Microbalance)등을 이용하여 도금특성 및 throwing power를 알아보았다. Cathode polarization 및 EQCM을 통한 구리 전착량을 알아본 결과 4가지의 mercapto 화합물 중 3-mercapto-1-propanesulfonic acid가 activator로서 가장 적당하였으며, 그 농도가 20 ppm에서 throwing power를 증가시키고, 농도 및 활성 과전압이 오직 $Cl^-$만 포함되었을 때보다 cathodic scan시 100 mV 만큼 shift되어 증착속도를 증가시킴을 알 수 있었다.

• Journal of Electrochemical Science and Technology
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• 제11권2호
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• pp.155-164
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• 2020

Here we report our preliminary results about nickel phosphide (Ni-P) electroless coating on the surface of cellulose paper (CP) and its feasibility as the anode for lithium (Li) batteries. In particular, CP can act as a flexible skeleton to maintain the mechanical structure, and the Ni-P film can play the roles of both the anode substrate and the active material in Li batteries. Ni-P films with different P contents were plated uniformly and compactly on the microfiber strands of CP. When they were tested as the anode for Li battery, their theoretical capacity per physical area was comparable to or higher than hypothetical pure graphite and P film electrodes having the same thickness. After the large irreversible capacity loss in the first charge/discharge process, the samples showed relatively reversible charge/discharge characteristics. All samples showed no separation of the plating layer and no detectable micro-cracks after cycling. When the charge cut-off voltage was adjusted, their capacity retention could be improved significantly. The electrochemical result was just about the same before and after mechanical bending with respect to the overall shape of voltage curve and capacity.

• 한국표면공학회지
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• 제41권5호
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• pp.232-239
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• 2008

The dental orthodontic mini-screw requires good mechanical properties and high corrosion resistance for implantation in the bone. The purpose of this study was to investigate the electrochemical characteristics of TiN and ZrN coated orthodontic mini-screws, mini-screws were used for experiment. Ion plating was carried out for mini-screw using Ti and Zr coating materials with nitrogen gas. Ion plated surface of each specimen w as o bserved with f ield emission scanning e lectron microscopy ( FE-SEM), e nergy dispersive x-ray spectroscopy (EDX), and electrochemical tester. The surface of TiN and ZrN coated mini-screw were more smooth than that of other kinds of non-coated mini-screw due to dercrease of machined defects. The corrosion current density of the TiN and ZrN coated mini-screw decreased compared to non-coated sample. The corrosion potential of TiN and ZrN coated mini-screw were higher than that of non-coated mini-screw in 0.9% NaCl solution. The pitting corrosion resistance increased in the order of ZrN coated, TiN coated and non-coated wire. Pitting potential of ZrN coated mini-screw was the highest in the other specimens.

• 한국표면공학회지
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• 제32권3호
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• pp.447-451
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• 1999

Silver has the highest electrical conductivity of all metals and consequently this property is an attractive feature which makes it a leading candidate for use in electronic devices. The research conducted was focused primarily on the development of a process for obtaining a deposited silver-coating onto alumina, for applications related to electrical-conducting devices and, ancillarily, catalysts. Alumina balls and plane substrates were utilized for the investigation. The coating process employed an aqueous ammoniacal silver-nitrate electrolytes with a formaldehyde solution as the reductant. Modifying additives-an activator which would be expected to promote good deposition-characteristics onto the (dielectric) substrate and an inhibitor which would obviate homogeneous reduction (precipitation) of silver was observed when the activator-containing silver-electrolyte reductant constituents were combined. However, the silver-electrolyte/reductant system with inhibitor could be employed (at 8$0^{\circ}C$) to achieve a viable (subject to future research optimization) coating on alumina. The influence of the processing temperature on the deposition process was delineated during the course of the research. The morphology of the deposited-silver on the alumina balls was assessed by SEM imaging. A tape-peel test was employed, with the plane substrates, to semi-quantitatively characterize the adhesion to the alumina.

• Corrosion Science and Technology
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• 제18권3호
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• pp.86-91
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• 2019

Generally, atmospheric corrosion is the electrochemical degradation of metal that can be caused by various corrosion factors of atmospheric components and weather, as well as air pollutants. Specifically, moisture and particles of sea salt and sulfur dioxide are major factors in atmospheric corrosion. Using galvanized steel is one of the most efficient ways to protect iron from corrosion by zinc plating on the surface of the iron. Galvanized steel is widely used in automobiles, building structures, roofing, and other industrial structures due to their high corrosion resistance relative to iron. The atmospheric corrosion of galvanized steel shows complex corrosion behavior, depending on the plating, coating thickness, atmospheric environment, and air pollutants. In addition, corrosion products are produced in different types of environments. The lifespans of galvanized steels may vary depending on the use environment. Therefore, this study investigated the corrosion behavior of galvannealed steel under atmospheric corrosion in two locations in Korea, and the lifespan prediction of galvannealed steel in rural and coastal environments was conducted by means of the potentiostatic dissolution test and the chemical cyclic corrosion test.

• 한국표면공학회지
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• 제34권6호
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• pp.553-567
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• 2001

Electrodeposition technology is widely used in industry for various kinds of coatings. Modifications in this technology led to several processes to meet various requirements. Electrolysis in ionic liquids has many advantages such as low energy consumption of energy, low pollutant emission and low operating costs. Although ionic liquids have already been used in liquid/liquid extraction processes, only recently their use in electrodeposition was exploited. Electrochemical deposition of composites is an expanding area. Coupled with the progress in the synthesis of nanometric powder, this research will open a large number of innovative materials. Pulse current plating is another electrodeposition technique which yields improved coatings. Although electrodeposition is now regarded as an environmental non-friendly process, it is economically viable and has many inherent advantages. For certain applications, alternatives to electrodeposition have not yet been fully implemented. Hence, continued research in this technology is warranted. This article reviews some recent advances in electrodeposition technology. Aspects of electrodeposition such as electrolysis in ionic liquids, electrodeposition of composites, pulse current plating techniques, metal and alloy deposition, compound deposition and effects of additives are discussed in this review.

• Korean Chemical Engineering Research
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• 제45권2호
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• pp.124-132
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• 2007

본 논문에서는 Ti 모재에 대한 Pt 도금 특성 연구를 통하여 안정한 platinized Ti 전극의 제조 방법이 제시되었으며, Sn이 흡착된 platinized Ti 전극의 질산염 이온에 대한 전기화학적 특성이 연구되었다. 에칭된 Ti 모재 표면에 전착된 Pt 도금 층 내에 적당하게 공간적 틈을 갖도록 도금하는 것은 도금 후 표면에 잔존하는 도금 용액 오염원을 제거하는데 효과적이며, 또 용액과 접하게 되는 전극의 실제 표면적을 최대화할 수 있었다. 제작된 platinized Ti 전극을 끓이는 과정과 전해 세정 과정을 통해 안정적이며 재현성 있게 만드는 것은 Sn-modified platinized Ti 전극에서 표면의 Sn 덮힘율을 정량화하는데 있어 매우 중요하였다. 전해 세정 과정은 전극 표면에 형성된 솜털과 같은 미세한 돌기들이 없어지면서 전극 표면을 안정화된 구조로 변화시켰다. 본 연구의 경우 질산염 이온의 환원을 목적으로 하는 Sn-modified platinized Ti 전극은 약 30분 도금 시간을 통해 제조한 경우가 가장 좋았다.

• 대한금속재료학회지
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• 제49권12호
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• pp.937-944
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• 2011

Studies have been carried out in order to reduce fuel-cladding chemical interaction (FCCI) behavior of metallic fuel in sodium-cooled fast reactors (SFR) using an electroplating technique. A $20{\mu}m$ thick Cr layer has been plated by the electrochemical method in the Sargent bath over the HT9 (12Cr-1Mo) clad material and diffusion couple tests of the U-10Zr metallic fuel as well as the rare earth alloy (70Ce-29La) have been conducted. The results show that the Cr plating can prevent FCCI behavior along the fuel-clad interface. However, cracks developed through the thickness during plating, which resulted in the migration of some fuel constituents. Variation of bath temperature, application of pulse current, and post heat treatment have been conducted to control such cracks. We found out that some conditions like the pulse current and the post heat treatment enhanced the layer property by reducing the internal cracks and improving the diffusion couple test.

• 전기화학회지
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• 제25권3호
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• pp.113-118
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• 2022

본 연구에서는 polyethylene glycol (PEG)이 구리전해도금에 미치는 영향을 cyclic voltammetry를 이용해 분석해보았다. PEG의 흡착은 함께 존재하는 음이온의 특이흡착에 따라 변화되었다. 가장 일반적인 도금액 성분인 sulfate 이온(SO₄^2-)이 존재하는 경우, PEG의 흡착이 억제되었으며 그로 인해 미약한 억제 효과가 관찰되었다. 실제로 도금액이 SO₄^2- 없이 특이흡착하지 않는 perchlorate 이온(ClO₄^-)으로만 이뤄진 경우, PEG는 도금 반응을 강하게 억제하였으며 억제 효과는 PEG의 분자량에 비례하여 나타났다. 반면, 염소 이온(Cl^-)의 특이흡착이 존재하는 경우 오히려 PEG의 억제 효과는 강화되었다. RDE 분석을 통해 강한 억제 효과는 PEG와 Cl^-간의 흡착구조체 형성에 의한 것임을 확인하였으며, 이러한 흡착 구조체 형성은 용액 조성에 따라 달라지는 특성을 나타내었다. 특히, 소수성 특성이 증가된 PEG 유도체의 경우 억제 효과가 더욱 강화되는 것으로 미루어, PEG와 Cl^-간의 흡착 구조체 형성에 PEG의 소수성 특성이 중요함을 확인하였다.

• Journal of Electrochemical Science and Technology
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• 제14권2호
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• pp.162-173
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• 2023

Aqueous zinc-ion batteries are considered as promising alternatives to lithium-ion batteries for energy storage owing to their safety and cost efficiency. However, their lifespan is limited by the irreversibility of Zn anodes because of Zn dendrite growth and side reactions such as the hydrogen evolution reaction and corrosion during cycling. Herein, we present a strategy to restrict direct contact between the Zn anode and aqueous electrolyte by fabricating a protective layer on the surface of Zn foil via phosphidation method. The Zn₃(PO₄)₂ protective layer effectively suppresses Zn dendrite growth and side reactions in aqueous electrolytes. The electrochemical properties of the Zn₃(PO₄)₂@Zn anode, such as the overpotential, linear polarization resistance, and hydrogen generation reaction, indicate that the protective layer can suppress interfacial corrosion and improve the electrochemical stability compared to that of bare Zn by preventing direct contact between the electrolyte and the active sites of Zn. Remarkably, MnO₂ Zn₃(PO₄)₂@Zn exhibited enhanced reversibility owing to the formation a stable porous layer, which effectively inhibited vertical dendrite growth by inducing the uniform plating of Zn²⁺ ions underneath the formed layer.