• Genomics & Informatics
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• v.4 no.3
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• pp.133-136
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• 2006

The adsorption of proteins on the surface of glass slides is essential for construction of protein chips. Previously, we prepared a nickel-coated plate by the spin-coating method for immobilization of His-tagged proteins. In order to know whether the structural factor is responsible for the immobilization of His-tagged proteins to the nickel-coated glass slide, we executed a series of experiments. First we purified a His-tagged protein after expressing the vector in E. coli BL21 (DE3). Then we obtained the unfolding curve for the His-tagged protein by using guanidine hydrochloride. Fractions unfolded were monitored by internal fluorescence spectroscopy. The ${\Delta}G_{H20}$ for unfolding was $2.27kcal/mol{/pm}0.52$. Then we tested if unfolded His-tagged proteins can be adsorbed to the nickel-coated plate, comparing with $Ni^{2+}-NTA$ (nitrilotriacetic acid) beads. Whereas unfolded His-tagged proteins were adsorbed to $Ni^{2+}-NTA$ beads, they did not bind to the nickel-coated plate. In conclusion, a structural factor is likely to be an important factor for constructing the protein chips, when His-tagged proteins will immobilize to the nickel-coated slides.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.169-174
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• 2012

Electromagnetic interference(EMI) shielding effectiveness(SE) was investigated in of woven fabric made of epoxy/copper-nickel fabrics and nickel coated carbon fiber reinforced acrylonitrile-butadiene-styrene(ABS) composites. The coaxial transmission line method was used to measure the EMI shielding effectiveness of the composites. We designed and constructed a measuring system, consisting of a network analyzer and a device that plays the serves as a sample holder and at the same time as a transmission medium of the incident electromagnetic wave. The measurement of SE were carried out frequency range from 100MHz to 2GHz. It is observed that the SE of the composits is the frequency dependent increase with the increase in nickel coated carbon fibre volume fraction. The nickel coating with 20wt% ABS composite was shown to exhibit up to 60dB of SE. The result that nickel coated carbon fibre ABS composite can be used for the purpose of EMI shielding as well as for some microwave applications.

• Journal of Ocean Engineering and Technology
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• v.15 no.3
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• pp.69-74
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• 2001

This paper was to investigate of a adhesiveness for the plasma sprayed coating materials did salt spray by acoustic emission method in tensile loadings. The powders used for the coating were nickel aluminum composite powder Ni-4.5wt.%Al and titanium dioxide powder $TiO_2$. These powders were coated on a carbon steel S45C by plasma spray method. The result solution was a 5% NaCl and the slat spray times were 2, 5 and 10 hours respectively. The salt solution penetrated into the surface of the substrate through pore of the coating layer built in the process of plasma spay. Corrosion productions formed on the surface of substrate. The adhesiveness between the substrate and the coating layer is weaken by corrosion and the exfoliation initiated chiefly at the corrosion surface of the substrate. The AE events and energy of the corroded coating specimens decreased as the salt spray times increased.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.344-349
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• 2001

This paper was to investigate of a adhesiveness for the plasma sprayed coating materials did salt spray by acoustic emission method in tensile loadings. The powders used for the coating were nickel aluminum composite powder Ni-4,5wt.%Al and titanium dioxide powder Ti02. These powders were coated on a carbon steel S45C by plasma spray method. The salt solution was a 5% NaCl and the salt spray times were 2, 5 and 10 hours respectively. The salt solution penetrated into the surface of the substrate through pore of the coating layer built in the process of plasma spay. Corrosion productions formed on the surface of substrate. The adhesiveness between the substrate and the coating layer is weaken by corrosion and the exfoliation initiated chiefly at the corrosion surface of the substrate. The AE events and energy of the corroded coating specimens decreased as the salt spray times increased.

• Journal of the Korean Chemical Society
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• v.28 no.6
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• pp.374-383
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• 1984

In order to elucidate the effect of alkali promoter on chemisorption of carbon monoxide on silica supported transition metal catalysts we have investigated the infrared spectra for carbon monoxide chemisorbed on silica supported nickel with and without potassium coating within the frequency range of 1800 ~ 2100cm$^{-1}$ at various nickel concentrations and CO pressures. For the system without potassium coating the IR band intensities are found to greatly depend on the nickel conwgfra concentration although the band positions are scarcely affected. The band positions are nearly coincident with those reported by other people, but we have clarified that the 2057cm$^{-1}$ band arises from Ni(CO)$_4$ molecules physisorbed on silicagel. Besides this, the effect of temperature on CO chemisorption has also been investigated. On coating with potassium we have found that all the bands observed for the system without potassium coating suffer red shifts by 2 ~ 10cm$^{-1}$ and the formation of Ni(CO)$_4$ is inhibited. Furthermore, we have recognized that on the nickel surface with potassium coating a disproportionation may occur to yield carbon dioxide molecules.

• 연구논문집
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• s.22
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• pp.151-160
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• 1992

The wear resistance of electroless Ni-P-X(X A1203, Diamond) composite coating layers was studied by Taber abrasion test technique. The wear resistance of composite coating layers was particularly relied upon the codeposited content, particle size and distribution of particles, and heat treatment of coating layers, as well as the electroless nickel plating bath employed. In this study, we lay emphasis on the wear resistance of electroless composite coating layers containing A1203 particles(1.2~Im, 6.7hIm, 11.5lIm, 20l1m) or diamond particles (1.5jim, 5gm). From the result of composite coating A1203 and diamond particles, the wear resistance of composite coating layers is as follows.

• Journal of the Korean institute of surface engineering
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• v.23 no.3
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• pp.173-182
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• 1990

In order to prevent the thermal and enviromenatal degradation of contact materials a nickel layer was plated as an undercoat of gold plating on the surface phosphorous bronze. The thickness of nikel and gold coating and chemical resistance of the coatings were measured at various conditions. Variation of morphology and chemical composition was studied by SEM, EDS and ESCA, respectively. Nickel layer was found to act as a thermal diffusion barrier and to retard the diffusion of copper from substrate to gold coating in the temperature $200^{\circ}C$~$400^{\circ}C$. below $200^{\circ}C$gold coated contacts showed a stable and low contanct resistance, while above $200^{\circ}C$ rapid diffusion of copper formed copper oxide on the surface layer and raised the contact resistance. With the nickel thinkness of abount 5$\mu$m as an undercoat the gold thinkness of $0.5\mu$m, showed satistactory (less than 1 m$\Omega$) contact resistance below 20$0^{\circ}C$ and corresponding gold thinkness increased to 1.0 m at $300^{\circ}C$~$400^{\circ}C$.

• Carbon letters
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• v.9 no.2
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• pp.105-107
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• 2008

In this work, we employed an electroless nickel plating on glass fibers in order to enhance the electric conductivity of fibers. And the effects of metal content and plating time on the conductivity of fibers were investigated. From the results, island-like metal clusters were found on the fiber surfaces in initial plating state, and perfect metallic layers were observed after 10 min of plating time. The thickness of metallic layers on fiber surfaces was proportion to plating time, and the electric conductivity showed similar trends. The nickel cluster sizes on fibers decreased with increasing plating time, indicating that surface energetics of the fibers could become more homogeneous and make well-packed metallic layers, resulting in the high conductivity of Ni/glass fibers.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.293-300
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• 2023

The global energy storage markets have gravitated to high-energy-density and low cost of lithium-ion batteries (LIBs) as the predominant system for energy storage such as electric vehicles (EVs). High-Ni layered oxides are considered promising next-generation cathode materials for LIBs owing to their significant advantages in terms of high energy density. However, the practical application of high-Ni cathodes remains challenging, because of their structural and surface instability. Although extensive studies have been conducted to mitigate these inherent instabilities, a two-step process involving the synthesis of the cathode and a dry/wet coating is essential. This study evaluates a one-step β-Li₂SnO₃ layer coating on the surface of LiNi_0.8Co_0.2O₂ (NC82) via the thermal segregation of Sn owing to the solubility limit with respect to the synthesis temperature. The doping, segregation, and phase transition of Sn were systematically revealed by structural analyses. Moreover, surface-engineered 5 mol% Sn-coated LiNi_0.8Co_0.2O₂ (NC82_Sn5%) exhibited superior capacity retention compared to bare NC82 owing to the stable surface coating layer. Thus, the developed one-step coating method is suitable for improving the properties of high-Ni layered oxide cathode materials for application in LIBs.

• Journal of the Korean institute of surface engineering
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• v.44 no.6
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• pp.246-249
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• 2011

Surface modification before coating nickel by coupling agents and/or etchant of glass did not provide enough adhesive strength of electroless nickel deposits on glass. Effect of heat treatments on hardness as well as adhesion of nickel deposits was studied by using tape test for adhesion, nanoindenter for hardness and glancing angle x-ray diffractometer (GAXRD) for phase characterization. Heat treatment improved hardness as well as adhesion. XRD results give that the improvements of adhesion and hardness are due to the formation of $NiSiO_4$ around the interface between the nickel deposits and the glass and the precipitation of $Ni_3P$ causing precipitation hardening, respectively. The details in effects of heat treatment on adhesion and hardness are described here.