• 분석과학
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• 제11권4호
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• pp.305-310
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• 1998

아민기를 함유한 Eriochrome Black T 유사체 염료에 cynauric chloride를 반응시켜 합성한 반응성 염료를 셀룰로오스 막(cellulose membrane)에 화학적으로 고정시켜서 2가 전이금속을 검출할 수 있는 광센서를 구성하였다. 이 광센서는 용액상 Eriochrome Black T와 마찬가지로 전이금속의 농도에 민감하게 감응한다. 이 광센서는 대표적으로 $Zn^{2+}$와 $Co^{2+}$에 대해서 각각 $6.3{\times}10^{-5}mol/l$와 $2.5{\times}10^{-4}mol/l$의 검출한계를 나타냈다. 이 광센서는 또한 흐름용액의 pH가 계속해서 변하는 조건하에서도 상당 시간 동안 그 감응성이 감소하지 않았다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.248-248
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• 2006

The notable feature of the Cu(II) coordination polymer investigated here is its ability to self-assemble into a double-stranded helical structure with regular grooves along the helical axis, through the combination of metal-chloride dimeric interactions and repulsive interactions, as an organizing force. It is also remarkable that the double-stranded helices self-organize into a 2-D columnar structure in both the bulk state and aqueous solution. These results represent a unique example that weak metal-ligand bridging interactions can provide a useful strategy to construct stable double-stranded helical nanotubes.

• 약학회지
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• 제47권6호
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• pp.356-360
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• 2003

Nitroso-2-naphthol-3,6-disulfonic acid, disodium salt (NRS) was used as an organic ligand to prepare basic drug-selective polymeric membrane electrode. The sensing membrane of the electrode consited of basic drug-meta1(II)-NRS as an ion-exchanger site in a poly(vinyl chloride) matrix plasticized with 2-nitrophenyl octyl ether (NPOE). The metal ions used were Fe$^{2+}$, Co$^{2+}$, Ni$^{2+}$ and Cu$^{2+}$. The electrodes exhibited fast and wide linear response in the basic drug concentration of 10$^{-5}$ ∼10$^{-3}$ mol/l with a response slope of 50∼60 mV/decade in a buffer solution of pH 4∼8. The electrodes exhibited good selectivity for many basic compounds.mpounds.

• Korean Chemical Engineering Research
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• 제50권2호
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• pp.211-216
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• 2012

염화제이철 수용액에 의한 스테인레스 강판의 식각반응에 관한 연구를 수행하였다. 식각액 교반속도, 식각온도, $Fe^{3+}$ 이온 농도, 식각액의 유리산도 및 비중 등 여러 공정변수가 식각속도에 미치는 영향에 대해 조사하였고, 그 결과, AK(aluminum-killed) 철, 크롬(chlomium) 강, 그리고 스테인레스 강(STS430J1L 합금)의 식각반응이 1차 반응식을 잘 따름을 알 수 있었다. 또한 식각액의 피로도(fatigue ratio)가 16% 이하로 유지되면 식각액 내에 슬러지가 발생하지 않으며, 식각된 강판의 표면거칠기 또한 좋아짐을 알 수 있었다. 본 연구에서 조사한 범위 내에서는, 식각액의 보메(Baume)가 증가하면 식각속도는 감소하나 유리산도가 식각속도에 미치는 영향은 미비함을 알 수 있었다. 한편 본 연구의 실험결과는 공정모델링을 통해 유도된 식각속도식의 계산결과와 잘 일치함을 알 수 있었다.

• 전기화학회지
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• 제10권3호
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• pp.179-183
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• 2007

The corrosion behavior of metal covered with mortar under a wet-dry cyclic condition were investigated to apply for the measurement of corrosion rates of reinforcing steel in concrete structure. The carbon steel in mortar having t=3 mm cover thickness was exposed to the alternate condition of 6 h immersion in chloride containing solution and 18 h drying at $25^{\circ}C$ and 50%RH. The electrochemical phenomena of a carbon steel and mortar interface was explained by an equivalent circuit consisting of a solution resistance, a charge transfer resistance and a CPE(Constant Phase Element). The corrosion rates were monitored continuously during exposure using an AC impedance technique. Simultaneously, the current distribution over the working electrode during impedance measurement was analyzed from the phase shift, $\theta$, in an intermediate frequency. The result showed that corrosion rate monitoring using an AC impedance method is suitable under the given exposure conditions even during the drying period when the metal is covered with the wetted mortar.

• Corrosion Science and Technology
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• 제3권5호
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• pp.194-197
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• 2004

The corrosion resistance of several kind of ME (Metal Evaporated) tape has been investigated both in mild sulfuric acid solution and NaCl solution by electrochemical impedance spectroscopy. It was found that the degradation of ME tapes was accelerated with increasing the concentration of sulfuric acid. There was no significant change in corrosion resistance when the concentration of NaCl was under 3.5 wt%. However, the impedance value decreased when the concentration of NaCl was up to 10 wt%. The degradation of backside of ME tapes was also investigated by AC impedance measurements. The results showed that the impedance behavior of backside plastic film changed with the concentration of sulfuric acid even at the beginning of immersion, implying the changing of the permeability for the backside of ME tapes. It was also found that the corrosion resistance of DVC (Digital Video Cassette) ME tape was better that that of Hi-8mm ME tapes in sulfuric acid solutions. Also, the backside of DVC ME tape showed better water resistance than that of Hi8 ME tapes.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.23-24
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• 2003

We synthesized a poly[2-(2'-hydroxyphenyl) benzoxazole] under the two step procedures of Suzuki coupling polymerization with corresponding monomers followed by the deprotection of benzyl group. The polymer in DMF solution is applicable to colorimetric sensing fluoride anion, which shows a color change from colorless to yellow. High sensitivity to fluoride anion compared to other anions such as phosphate, chloride, and sulfate is ascribed to the high coordination ability of the 2-(2'-hydroxy phenyl)benzoxazole moiety in the polymer chain. Emission shift by metal cations, which can be applied to fluorescent sensing w as also observed in the polymer solution.

• 센서학회지
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• 제16권1호
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• pp.11-16
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• 2007

CuO is an important transition metal oxide with many practical applications such as catalysts, p-type semiconductor, solar cells, magnetic storage media and cathode materials. In this contribution, nanocrystalline CuO powders were prepared by solution reduction method using copper chloride ($CuCl_{2}{\cdot}2H_{2}O$), hydrazine ($N_{2}H_{4}$) and NaOH and subsequent heat treatment. The gas sensor using nanocrystalline CuO powders showed high sensitivities to acetone and ethanol.

• Journal of Pharmaceutical Investigation
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• 제20권3호
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• pp.145-152
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• 1990

Zirconium pyrithione complex was prepared by reaction of sodium-pyrithione solution and zirconyl chloride solution. The physico-chemical properties of the complex was examined by means of IR, XRD, DSC and NMR. And the stability of Zr-complex was investigated on the basis of accelerated stability analysis under conditions of temp. elevation, UV radiation and pH dependence. The result indicates that the ratio of the ligand to metal in Zr-pyrithione complex was determined 4:1, and its stability constant was $4.643{\times}10^4$. The rate order of decomposition of the complex was apparent first-order reaction of which rate constant and the decomposition rate was not only accelerated by effect of heat and UV radiation but was catalyzed by specific acid-base catalysis considered the pH dependence for the hydrolysis of the complex and the suspension was most stable over the range pH 4-8 indicating that solvent catalysis is the primary made of reaction in this region.

• 한국표면공학회지
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• 제47권5호
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• pp.269-274
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• 2014

Electroless plating process as a solution deposition method is a viable means of preparing conductive metal films on non-conducting substrates through chemical reactions. In the present study, the preparation and properties of electroless Ni-plating on flexible silicone rubber are described. The process has been performed using a conventional Ni(P) chemical bath. Additives and complexing agents such as ammonium chloride and glycine were added and the reaction pH was controlled by NaOH aqueous solution. Ni deposition rate and crystallinity have been found to vary with pH and temperature of the plating bath. It was shown that Ni-films having the high crystallinity, enhanced adhesion and optimum electric conductivity were formed uniformly on silicone rubber substrates under pH 7 at $70^{\circ}C$. The conductive Ni-plated silicone rubber showed a high electromagnetic interference shielding effect in the 400 MHz-1 GHz range.