• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.863-867
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• 2008

Pitch based activated carbon fiber(ACF) was prepared from reformed naphtha cracking bottom oil(NCB oil) by melt spinning. The fibers obtained were stabilized, carbonized, and then steam activated. The ACF was sensitized with Pd-Sn catalytic nuclei via a single-step activation approach. This sensitized ACF was used as precursors for obtaining copper plated ACFs via electroless plating. ACFs uniformly decorated with metal particles were obtained with reduced copper plating in the reaction solution. Effects of the amount of copper on characteristics of ACF/Cu catalysts were investigated through BET surface area, X-ray diffraction, scanning emission microscopy, and ICP. The amount of copper increased with plating time, but the surface area as well as the pore volume decreased. NO conversion increased with reaction temperature. NO conversion decreased with increasing the amount of copper, which is seemed to be due to the reduction of surface area as well as the dispersion of copper.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.2102-2104
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• 2004

In this study, sheathless electrospray from PDMS/glass microchips with conducting metal emitter tip is described. A chip-based capillary electrophoresis/mass spectrometry (CE/MS) system has advantages of the CE separation and on-line electrospray detection of peptide solution. We have fabricated a new electrospray ionization(ESI) device composed of the metal emitter tip and CE separation channel monolithically in a glass microchip. The separation channel and metal emitter tip are fabricated using a glass wet etching and gold electro plating process, respectively. The fabricated micro electrospray chip was tested by spraying peptide sample for mass spectrometric analysis. Singlely-charged peak and doublely-charged peak of peptide were detected and further MS/MS fragmentation was performed in each peak. Direct comparisons with conventional glass or fused silica emitters showed very similar performance with respect to signal strength and stability.

• Journal of the Korean institute of surface engineering
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• v.32 no.6
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• pp.686-694
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• 1999

Insoluble anodes of the Ta/Ir mixed metal oxide for electrodeposition of Ni-W alloy in ammoniacal citrate bath were prepared by thermal decomposition method. Ti plate was etched in boiling oxalic acid solution and coated with ethanol solution of $TaCl_{5}$ and $IrCl_4$ mixed in a fixed ratio, followed by drying and treating at various temperatures. The coating layer of these insoluble anode was characterized by SEM, EDX, XRD and DSC. The decomposition rate of citric acid in plating bath was determined by measuring the $CO_2$ gas evolved at the anodes with Gas Chromatography. Evolution of $CO_2$ gas from Ta/Ir oxide anodes decreased about 5% compared with that of Pt. The $CO_2$ gas evolution was increased with the amount of Ir-oxide in the coatings. The coatings which have more than 40% ratio of Ta content and heat-treated at the temperature higher than $400^{\circ}C$ showed better efficiency

• Analytical Science and Technology
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• v.19 no.3
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• pp.226-238
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• 2006

The electroplating of the Ag ions from aqueous solution on activated porous carbons was investigated over a wide range of plating time. The adsorption capacities of Ag metallic carbons were associated with their internal porosity and were related to physical properties such as surface area and pore size distribution. And, surface morphologies and quantitative analysis for the metal supported carbons are investigated by scanning electron microscopy (SEM) and energy disperse X-ray (EDX) measurements to explain the changes in adsorption properties. It is considered that the pH is an very important factor at the reason of water pollutant with increasing acidity in industrial field. The results of ICP-AES analysis showed that the residual concentration of Ag ions decreased with an increasing electroplating time. The metallic Ag-activated porous carbons electroplated showed microbicidal effects and strong antibacterial activity against six kinds of strains that were used. Finally, we confirmed that the presence of the electrolytic plated Ag-activated porous carbons is a determining factor in the HCl removal by chemical reaction, clarifying the surface chemical behavior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.339-339
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• 2007

Metal coating on ceramic powder has long been attracting interest for various applications such as superconductor where the brittle nature of high temperature ceramic superconductor was complemented by silver coating and metalloceramics where mechanical property improvement was achieved via electroless plating. More recently it has become of great interest in embedded passive device applications since metal coating on ceramic particles may result in the enhancement of the dielectric properties of ceramic-polymer composite capacitors. In our study, nickel ion-containing solution was used for coating commercial capacitor-grade $BaTiO_3$ powder. After filtering process, the powder was dried and heat-treated in 5% forming gas at $900^{\circ}C$. XRD and TEM were utilized for the observation of crystallization behavior and morphology of the particles. It was found that the nickel coating characteristics were strongly dependent on the several parameters and processing variables, such as starting $BaTiO_3$ particle size, nickel source, solution chemistry, coating temperature and time. In this paper, the effects of these variables on the coating characteristics will be presented in some detail.

• Korean Journal of Materials Research
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• v.5 no.8
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• pp.1013-1019
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• 1995

The thin plate of Co-Ni-P was deposited on the polyester film by the electroless plating method. Through present experiments, deposition rates and metal compositions of the plates were determined according to compositions of solution, pH and temperature. Also, magnetic properties of plates were examined according to metal compositions. Considering magnetic properties and deposition rates of electroless plating, the best condition was obtained as pH of 8.5 and 90℃. It was observed that metal compositions were evidently varied by the pH of solutions and the concentration of complex agents. However. they were not affected by other factors. At the optimum condition, the composition of the plate was Co(78%), Ni(16%), and P(6%). Also, it was found that the coercive force was 370 Oe, and squareness was 0.65 at this condition. Magnetic properties (hard or soft) of thin plates were determined by metal compositions. Therefore. the plate became soft magnetic plate as the composition of nickel increased over 30 per cents. The crystal structure of the soft magnetic plate was found to be amorphous in which it was strongly oriented to the (111)phahe of nickel. On the ohter hand, the hard magnetic place was found to be hcp crystalline of α-cobalt which was oriented to the (101)phase of cobalt and the (100)phase of cobalt.

• Journal of the Korean institute of surface engineering
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• v.32 no.6
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• pp.709-716
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• 1999

Ceramic is select for an alternative substrate material for high-speed circuits due to its low-thermal expansion. As, in this study, ceramic was prepared by ISG (interlayer sol-gel) process using metal salts and a metal alkoxide as the starting materials. Generally ceramic substrate is used electroless copper plating for the metallization. But it has been indicate weakely the adhesion strength between the substrate and copper layer. Therefore, this research, using the ISG process on the preparation of homogeneous and possible preparation at law temperature fabricated sol solution. Using of the dip coating method was coated for the purpose of giving the anchoring effect on the coating layer and enhancing the adhesion strength between the $Al_2$O$_3$ substrate and copper layer. This study examined primary the characteristic of the sol making condition and differential thermal analysis (DTA) X-ray diffraction (XRD) were mearsured to identify the crystal phase of heat treatment specimens. The morphology of the coated films were studied by scanning electron microscopy(SEM). As a resurt, XRD analysis was obtained patterns of $\alpha$-cordierite after heat-treatment about 2 hours at $1000^{\circ}C$. SEM analysis could have seen a large number of voids on coated film. The more contants of$ Al_2$$O_3$ Wt% was increased the more voids was advanced. Peel adhesion strength has a maximum in the contants of the TEOS:ANE of 1:0.7 mole%. In this case, adhesion strength has been measured 1150gf, peel adhesion strength were about 10 times more than uncoated of the ceramics film.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.259-263
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• 2001

There are several steps such as slicing, lapping, chemical etching and mechanical polishing in the silicon wafer production process. The chemical etching step is necessary to remove damaged layer caused In the slicing and lapping steps. The typical etching liquor is the acid mixture comprising nitric acid, acetic acid and hydrofluoric acid. At present, the waste acid is treated by a neutralization method with a high alkali cost and balky solid residue. A solvent extraction method is applicable to separate and recover each acid. Acetic acid is first separated from the waste liquor using 2-ethlyhexyl alcohols as an extractant. Then, nitric acid is recovered using TBP(Tri-butyl phosphate) as an extractant. Finally hydrofluoric acid is separated with the TBP solvent extraction. The expected recovered acids in this process are 2㏖/l acetic acid, 6㏖/1 nitric acid and 6㏖/l hydrofluoric acid. The yields of this process are almost 100% for acetic acid and nitric acid. On the other hand, it is important to recover and reuse the metal values contained in various industrial wastes in a viewpoint of environmental preservation. Most of industrial products are made through the processes to separate impurities in raw materials, solid and liquid wastes being necessarily discharged as industrial wastes. Chemical methods such as solvent extraction, ion exchange and membrane, and physical methods such as heavy media separation, magnetic separation and electrostatic separation are considered as the methods for separation and recovery of the metal values from the wastes. Some examples of the application of solvent extraction to the treatment of wastes such as Ni-Co alloy scrap, Sm-Co alloy scrap, fly ash and flue dust, and liquid wastes such as plating solution, the rinse solution, etching solution and pickling solution are introduced.

• Journal of the Korean institute of surface engineering
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• v.48 no.3
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• pp.73-81
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• 2015

Chloride plating solution was fabricated by dissolving metal Ni powders in solution with HCl and deionized water. Effects of deposition conditions on the properties of Ni films electrodeposited from chloride baths were studied. Current efficiency of Ni films electrodeposited from the baths containing saccharin was decreased with increasing the current density. Residual stress of Ni thin films ware measured to be about 230 ~ 435 MPa in the range of current density of $10{\sim}25mA/cm^2$. Cathode current efficiency in baths without saccharin was initially increased with increasing pH, while it was decreased with increasing pH further. Cathode current efficiency in baths with saccharin (except at pH 2) exhibited less 10 ~ 20% than that in baths without saccharin. Residual stress of Ni films electrodeposited from baths without saccharin was measured to be 388 ~ 473 MPa in the range of pH 2 ~ pH 5 and then was increased to 551 MPa at pH 6. On the other hand, residual stress of Ni films electrodeposited from baths with saccharin was increased with increasing pH. Surface morphology was strongly affected by the change of current density, but slightly by solution pH and addition of saccharin.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.180-186
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• 2020

In this work, a metal-ligand solution (Cu-EDTA) was prepared based on the molecular precursor method and the solution was spin-coated onto 3D printed flexible photosensitive resin sheets. After being processed by microwave, a laser with a wavelength of 355 nm was utilized to scan the spin-coated sheets and then the sheets were immersed in an electroless copper plating solution to deposit copper wires. With the help of microwave processing, the adhesion between copper wires and substrate was improved which should result from the increase of roughness, decrease of contact angle and the consistent orientation of coated film according to the results of 3D profilometer and SEM. XPS results showed that copper seeds formed after laser scanning. Using the 3D printed flexible sheets as cathode and galvanized iron as anode, electrochemical machining was conducted.