• Analytical Science and Technology
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• v.13 no.2
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• pp.173-178
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• 2000

A new open-chain ligand containing two phenol groups, 1, 14-Bis (2-hydroxybenzyl)-2, 6, 9, 12-tetraazatetradecane(bsated) was synthesized as its tetrahydrochloride salt and characterized by elemental analysis, mass, infrared and NMR. Its proton dissociation constants ($logK^n{_H}$) and stability constants ($logK_{ML}$) toward $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$ and $Zn^{2+}$ were determined at $25^{\circ}C$ and 0.10M($KNO_3$) ionic strength in aqueous solution by potentiometry. The X-ray structure of its copper (II) complex [Cu(bsated)]$(ClO_4)_2$ was reported: Monoclinic space group $P2_1/n$, $a=17.856(4){\AA}$, $b=17.709(1){\AA}$, $c=8.539(2){\AA}$, $V=2700(2){\AA}$ with Z=4. Electrochemical studies of [Cu(bsated)]$(ClO_4)_2$ complex in dimethyl sulfoxide (DMSO) solution containing tetrabutylammonium perchlorate (supporting electrolyte) were carried out by cyclic voltammograms (CV) and normal pulse voltammetry (NPV).

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1311-1314
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• 2008

We have developed new electrical dopants of rhenium oxide ($ReO_3$) and cupper iodide (CuI) as p-dopants and rubidium carbonate ($Rb_2CO_3$) as an n-dopant, respectively. $ReO_3$ has advantage of low temperature evaporation (about $300^{\circ}C$) with enhanced device stability. Various kinds of high performance organic light emitting diodes have been realized, including bottom emission, tandem, and top-emission OLEDs.

• Electrical & Electronic Materials
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• v.4 no.3
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• pp.201-210
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• 1991

본 논문에서는 (B $i_{1-x}$ P $b_{x}$)$_{2}$S $r_{2}$C $a_{2}$C $u_{3.6}$ $O_{y}$ (x=0~0.5)로 조성된 분말의 최적 하소온도를 결정하고 시편의 최적 소결온도를 규명하기 위하여 열분석을 하였다. 또 단일상의 고온 초전도체를 제작하기 위하여 열처리 온도, 시간 및 Pb 함량 변화에 따라 제작된 시편의 미세구조, 조성, 전기저항 및 전류밀도를 측정하여 상호 연관성을 종합적으로 분석, 검토하여 상변이에 관한 원인을 규명하고자 하였다. 또한 실용화 전 단계로서 임계특성 해석을 위하여 성형조건을 변화시켜 시편을 제작, 전류밀도값을 측정하였다.였다.다.

• Journal of the Korean Chemical Society
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• v.9 no.4
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• pp.179-184
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• 1965

Korean acid clays and Japanese acid clay were 1 N KCl solution and then their acidities were determined by measuring pH of the filtrates produced. And on examining the effect of neutral salt solution, such as KCl, NaCl, $BaCl_2,\;Pb(NO_3)_2\;and\;CuSO_4$, on the acidity, it was found that the effect decreased in order mentioned above and this situation proved to be in accord with Lyotrope series, i.e., the order of $K^+>Na^+>Ba^{++}>Pb^{++}>Cu^{++}.$ And after adsorbing cation, $Al_2O_3\;and\;Fe_2O_3$ which dissolved out of acid clay were measured, with the result that the amounts dissolved out were nearly proportional to acidity. This result accords with Kobayashi and Yamamoto's theory that the cause for acidity of clays is due to the fact that HCl which is formed initially by exchange of cation reacts with solid clay, and then chlorides dissolved out bring about hydrolysis, then resulting in the second formation of HCl. On measuring the rate which acid clay adsorbed dye in aqueous solution of basic and acid dyes, it was found that acid dye had no relation to acidity, and though it was not adsorbed by acid clay, the adsorption rate of basic dye was proportional to acidity. After adsorbing basic dye, pH was proportional to both acidity of solid acid and its adsorption rate of dye. Hence, it was concluded that the adsorption of basic dye was in accord with adsorption mechanism of neutral salt. This study led to find the acidic cause of solid acid and its adsorption mechanism of dye in aqueous solution.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.307-314
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• 1986

Cu(II) binding mechanisms with water soluble organic fractions (WSOF) extracted from an agricultural soil (W), a soil treated with sludge for 6 years ($WS_6$), a sludge-soil mixture incubated for one week ($WS_1$), and sewage sludge (SS) were studied by electron spin resonance (ESR) spectroscopy and potentiometric titrations. Cu(II)-WSOF complexes produced $g_{11}$ values which were larger than $g_{\perp}$ values, indicating that the coordination of Cu(II) complex was an elongated octahedron. At liquid $N_2$ temperature (77K), the Cu(II)-W complex showed an anisotropic ESR spectrum while the Cu(II)-SS complex showed an isotropic spectrum. These spectral results suggest that the oxygen donor ligands of W may form relatively strong bonds with $Cu^{2+}$ due to extensive chelation while ligands of SS may form little or no chelate bonds with $Cu^{2+}$. The ESR spectra of Cu(II)-SS complex also suggest that each of four in-plane ligands (e.g., $COO^-$, $H_2O$, $Cl^-$, etc.) may act independently as monodentate ligands. Oxygen donor ligands such as aromatic carboxyl groups were probably the major Cu(II) binding sites in W. Sulfonate, aliphatic carboxyl group, and N-containing ligands were probably the major binding sites in SS at pH 5. The Cu(II) complexation with N-containing groups increased as sludge was added to the soil. Much higher (6x) pyridine concentrations were required to displace W from Cu(II)-W complex as compared to the Cu(II)-SS complex.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.5-5
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• 2010

$(Na_{0.5}K_{0.5})NbO_3$ (NKN) ceramic with 1.5 mol% CuO added (NKNC) was well sintered even at a low temperature of $900^{\circ}C$ with the addition of ZnO. Most of the ZnO reacted with the CuO and formed the liquid phase that assisted the densification of the specimens at $900^{\circ}C$. A few $Zn^{2+}$ ions entered the matrix of the specimens and increased the coercive field ($E_c$) and $Q_m$ values of the specimens. High-piezoelectric properties of $k_p=0.37$, $Q_m=755$, and ${\varepsilon}_3\;^T/{\varepsilon}_0=327$ were obtained from the NKNC ceramics containing 1.0 mol% ZnO sintered at $900^{\circ}C$ for 2 h.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.311-315
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• 1991

The formation and transition of 2212 and 2223 phase have been studied in BPSCCO system. The 2212 phase formed in early sintering state reacts on $Ca_2PbO_4,\;Ca_2CuO_3$ and CuO during sintering process and thus produces the 2223 phase. A long sintering period is need to fabricate the superconductor with large volume fraction of 2223 phase. Also, the thin plate-like grains composed of Bi, Sr, Ca and Cu contribute to 2223 phase formation. Though the sample has lower volume fraction of 2223 phase, the critical temperature is measured highly in case of the grain grown to plate-like shape. In this work, the critical temperature of the sample sintered for 264 hr in air was measured 108 K. Microstructure of the sample was varied with condition of heat treatment after sintering process and the sample annealed with $500^{\circ}C$ for 5 hr showed excellent charateristics of 2223 phase formation.

• Environmental Engineering Research
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• v.25 no.2
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• pp.186-196
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• 2020

Pillared clays with Zr and Fe/Cu/Zr polycations have been prepared from natural clays found in large deposits of Kazakhstan and assessed as catalysts for the catalytic wet peroxide oxidation (CWPO), using 4-nitrophenol (4-NP) as model compound. The performance of the catalysts was followed by measuring the concentration of 4-NP, H₂O₂ and the total organic carbon (TOC), considering C_4-NP = 5 g L^-1, $C_{H_2O_2}$ = 17.8 g L^-1, C_cat = 2.5 g L^-1, initial pH = 3.0 and T = 50℃. At those selected conditions, the pillared clays showed higher activity than natural clays in the CWPO of 4-NP. The conversion of the model pollutant was complete when Fe/Cu/Zr-PILCs were used, with the TOC removal reaching 78.4% after 24 h with the best Fe/Cu/Zr-PILC. The H₂O₂, 4-NP and TOC time-evolution was well described by a kinetic model based on TOC lumps in three blocks, considering the initial TOC (corresponding to 4-NP), the production of oxidizable intermediates and the formation of refractory products.

• Bulletin of the Korean Chemical Society
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• v.11 no.1
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• pp.25-28
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• 1990

The superconducting properties have been studied for high-Tc superconductors of the $Bi_{2-x}Mo_xSr_2Ca_2Cu_3O_y$ system (x = 0.03-0.30). The crystal structure is pseudo tetragonal with the average lattice parameters a = 5.38 ${\AA}$, b = 5.44 ${\AA}$ and c = 30.6 ${\AA}$. All samples exhibit superconductivity with Tc offset at 79 K and Tc onset at 90-115 K. The Tc onset point decreases with increasing x, but the Tc offset points are nearly the same for all samples. Scanning electron micrographs show a special growth behavior of the grains with a plate shape. It is suggested that the decrease in Tc onset points with substitution of Mo for Bi is due to the decrease in lattice parameters and to the p-orbital of Mo. It is concluded that Mo does not play a crucial role in the superconducting transition of the $Bi_2Sr_2Ca_2Cu_3O_y$ system.

• Bulletin of the Korean Chemical Society
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• v.11 no.6
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• pp.560-563
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• 1990

A.c. susceptibility for $Bi_{1.4}Pb_{0.6}Sr_2Ca_2Cu_{3.6}O_x$ superconductor is measured as a function of temperature at different value of a.c. magnetic field amplitude. Two transition steps are attributed to the intergranular and intragranular properties. Based on Bean's critical state model, intergranular critical current density, $J_c^{gb}$ (11 $A/cm^2$ at 77 K) and intragranular critical current density, $J_c^g (7{\times}10^3\;A/cm^2$ at 100 K) are estimated. The low values of $J_c^{gb}$and $J_c^g$ reflect a poor nature of coupling between grains and the low pinning force density of intragrain in $Bi_{1.4}Pb_{0.6}Sr_2Ca_2Cu_{3.6}O_x$ superconductor.