• 한국표면공학회지
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• 제4권1호
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• pp.5-15
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• 1971

"Rapid Determination of Boric Acid in Nickel Plating Solution" by the addition of Na$_2$C$_2$O$_4$ and thus preventing the precipitation of i(OH)$_2$ during titiration , has previously been reported. In this paper, the exact amount of glycerine and the complexing possibility of oxalate with nickel has been determined by measn of conductivity titrations. This experimental work has been supported by the mathematical application of the Debye-Huckel and mass action equitions as well as statistical analysis. The results were ; (1) Fro determining boric acid in nickel plating solution, 20 ml of 400ml/ι glycerine was sufficient, since 97% of the H$_3$BO$_3$ was dissoicated by this addition. (2) In the absence of Na$_2$C$_2$O$_4$ the continious precipitation of Ni(OH)$_2$ during titration with NaOH even past end -point for boric acid determination resulted in considerable anlaytical error. (3) In the presence of Na$_2$C$_2$O$_4$ during titration , Ni++ combined with C$_2$O$_4$-to form NiC$_2$O$_4$. The solution with this precititate of very fine, colloidal , trantsparent particles, remained quite clear for approximately 2 hours. Therefore it was shown that the presence of Na$_2$C$_2$O$_4$ prevents the formation of gross Ni(OH)$_2$ precititation by forming NiC$_2$O$_4$ instead of a complex salt with Ni++ , which did not interfere with the visible determination of the end point for boric acid with NaOH titation. This observous may be interpreted in the light of the previously published solubility ratio for NiC$_2$O$_4$ and Ni(OH)$_2$, 0.3mg/100g H$_2$O(25$^{\circ}C$), respectively. Precipitation of the less soluble , albeit transparent salt, NiC$_2$O$_4$ precluded therefore the precipitation of the Ni(OH)$_2$ salt.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1419-1421
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• 1995

Nickel micro-structures are fabricated by electroless plating which shows better uniformity. Positive resist AZ4562 of 7 um thickness is patterned with minimum width of 2 um on poly-silicon as for sacrificial layer. The growth rate of Ni electroless plating is 10um/h both for the seed layer of Pt and TiW. TiW is found to be more practical than Pt, since it is very difficult to remove Pt with negligible damage to Ni structures.

• 한국기계가공학회지
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• 제14권1호
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• pp.15-20
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• 2015

I developed a high-quality metal door with a hologram-pattern design using a high-speed electroforming process. In this study, the major processes were master production, conducting grant, nickel-sulfamate acid electroforming, ablation treatment, and final dressing. The processing system was provided with a nickel sulfamate pole, and a rotary-pole PP-plating jig in a circular tank. This approach could reduce defects and errors, as much as possible, by its use of a hologram pattern to create the master of a metal door. The thin-sheet metal-creation process for the door built-in metal pattern using electroforming with hologram was successful.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.188-190
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• 2006

본 연구에서는 Anodic Aluminum Oxide(AAO) 템플레이트를 이용하여 전기도금법으로 일정한 길이와 고밀도 대면적의 Nickel nanorod를 제작하였다. 전기도금법으로 AAO-템플레이트내를 채우는 방법으로 제작되었다. 그 결과 직경 $80{\sim}100$ nm, 길이 $0.5{\mu}m$ 가량의 균일한 nanorod를 직경 40mm, 두께 $0.8{\mu}m$의 대면적 원형 AAO-템플레이트에 가득 채우는데 성공 하였으며 AAO 템플레이트는 제거되어 기판 위에 free-standing 되는 구조로 제작 되었다

• 한국전기전자재료학회논문지
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• 제20권2호
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• pp.118-123
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• 2007

The purpose of this work was to investigate the design and fabrication process effects on electrical properties in high capacitance multilayer ceramic capacitor (MLCC) with nickel electrode. Dielectric breakdown voltage and insulation resistance value were decreased with increasing stack layer number, but dielectric constant and capacitance were increased. With increasing green sheet thickness, dielectric breakdown voltage, C-V and I-V properties were also increased. The major reasons of the effects were thought to be the defects generated extrinsically during fabrication process and interfacial reactions formed between nickel electrode and dielectric layer. These investigations clearly showed the influence of both green sheet thick ness and stack layer number on the electrical properties in fabricating the MLCC.

• 한국표면공학회지
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• 제3권1호
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• pp.7-12
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• 1970

Only mannitol or glycerine is generally used for the determination of boric acid in a nickel plating solution in order to make its acidic property so strong that it can be titrated with NaOH. However, these solutions give very amgiguous color change of indicator due to the precipitation of nickel salts . Therefore, only experienced dchemistsorwell trained workimen can accurately confirm the actual end point of the titratiion. For eliminating such interference of nickel salts and easily confirming the end point by any persons , the author attempted to find out a solution which produces no precipitates during the titration in these experiments, and also he tried to funish the reason for ambiguousness in titration. The following results were obtained after many experiments. (1) In any titrations which produce nickel salts such nI(oh)$_2$, the salt is formed umption very approximate to the end point, which shows some error by the consumption of titrant(NaOH) . Then, the pink color of phenolphthalein is absorbed by Ni(OH)$_2$ and the pH jumping at the end pint is also diminished to as little as less than 15% of the total phenophthalein ph range. (2) Known methods by complex salts of citrate,w hich do not produce precipitates of Ni(OH)$_2$, are also not very satisfactory, because, the pH jumping at the end point is only about 35% and the color change of phenolphthalein is form blue-green to purple-blue. (3) New method by complex salts of oxalate were attempted in these experiments. They also did not produce precipitates of Ni(OH)$_2$ and were very satisfactory in color change at the end of point was about 65% and the color change was from blue-green to purpled. In this methods, analytica cost was minimized by the use of less amounts of cheaper chemicals than the conventional citrates complex methods. The mixture of chemicals used was composed methods. The mixture of chemical used was composed of 37g/ι of sodium oxalate(Na$_2$C$_2$O$_4$$.$5H$_2$O), 2g/ι of phenolphthalein, and 400ml /ι of glycerin. The accuracy of analysis was within the error of 0.5%. (4) The procedure of analysis was as follows. One ml of nickel plating solution was taken out and to it were added 20ml of water and 20 ml of the above mixture for the indicator. The solution was titrated with 0.1N NaOH. The quantity of boric acid was calculated by the following equation. Boric acid (g/ι) = 6.184${\times}$F${\times}$ml .

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1747-1751
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• 2006

The dinuclear tetraazadiphenol macrocyclic nickel(II) complexes [$Ni_2$([20]-DCHDC)]$Cl_2$ (I), [$Ni_2$([20]-DCHDC)]$(ClO_4)_2{\cdot}2CH_3CN $ (II(b)) and [$Ni_2$([20]-DCHDC)$(NCS)_2$] (III) {$H_2$[20]-DCHDC = 14,29-dimethyl-3,10,18,25-tetraazapentacyclo-[25,3,1,$0^{4,9}$,$1^{12,16}$,$0^{19,24}$]ditriacontane-2,10,12,14,16(32),17,27(31), 28,30-decane-31,32-diol} have been synthesized by self-assembly and characterized by elemental analyses, conductances, FT-IR and FAB-MS spectra, and single crystal X-ray diffraction. The crystal structure of II(b) is determined. It crystallizes in the monoclinic space group P2(1)/c. The coordination geometries around Ni(II) ions in I and II(b) are identical and square planes. In complex III each Ni(II) ion is coordinated to $N_2O_2$ plane from the macrocycle and N atoms of NCS- ions occupying the axial positions, forming a square pyramidal geometry. The nonbonded Ni…Ni intermetallic separation in the complex II(b) is 2.8078(10) $\AA$. The FAB mass spectra of I, II and III display major fragments at m/z 635.1, 699.4 and 662.4 corresponding to [$Ni_2$([20]-DCHDC)(Cl + 2H)]$^+$, [$Ni_2$([20]-DCHDC)$(ClO_4\;+\;2H)]^+$ and [$Ni_2$([20]-DCHDC)(NCS) + 6H]$^+$, respectively.

• Bulletin of the Korean Chemical Society
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• 제27권10호
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• pp.1705-1707
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• 2006

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2003년도 High Temperature Superconductivity Vol.XIII
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• pp.32-32
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• 2003

• Corrosion Science and Technology
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• 제2권1호
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• pp.1-6
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• 2003

A comprehensive coverage of corrosion in batteries is rendered difficult by the wide choice of materials, environments and physical features as obtained in practical settings. Understanding of the complex processes that occur in these electrochemical systems gets clearer as new theoretical approaches backed by sophisticated analytical and characterization techniques continue to provide valuable insights which aid in controlling/mitigating wasteful corrosion reactions which affect battery shelf-life, cycle life, rate capability and capacity. In the light of the above, I limit myself to a discussion on corrosion aspects in representative system such as conventional Leclanche, lead-acid battery and magnesium batteries, and advanced lithium systems.