• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.2105-2110
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• 2013

Carbon-fiber-supported NiO catalytic filters for oxidation of volatile organic compounds were prepared by electroless Ni-P plating and subsequent annealing processes. Surface structure and crystallinity of NiO film on carbon fiber could be modified by post-annealing at different temperatures (500 and $650^{\circ}C$). Catalytic thermal decompositions of toluene over these catalytic filters were investigated. $500^{\circ}C$-annealed sample showed a higher catalytic reactivity toward toluene decomposition than $650^{\circ}C$-annealed one under same conditions, despite of its lower surface area and toluene adsorption capacity. X-ray diffraction and X-ray photoelectron spectroscopy studies suggest that amorphous structures of NiO on $500^{\circ}C$-annealed catalyst caused the higher reactivity for oxidation of toluene than that of $650^{\circ}C$-annealed sample with a higher crystallinity.

• 대한화학회지
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• 제24권1호
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• pp.15-19
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• 1980

Glycinato 및 glycine ester 리간드의 전자구조와 반응성을 조사하기 위하여 CNDO/2와 EHT 분자궤도함수법을 적용하였다. 두자리 배위자로 작용하는 glycinato 리간드의 구조는 탄소에서 질소쪽으로 가는 결합이 ${\Delta}O_4C_3C_2$ 와 ${\Delta}O_3C_2N_1$ 평면에서 $105^{\circ}9'$의 dihedral angle을 가지는 Gly-I 구조가 Gly Ⅱ 구조보다 안정함을 알았으며, glycine ester 리간드에 대한 에너지 성분 분석 결과로서 alkyl가 치환에 따른 전자효과를 볼 수 있었다. CNDO/2 MO 계산으로 얻은 전자밀도 $q_N$값으로부터 리간드의 안정도 순위는 Glycinato>Gly-Et-Ester>Gly-i-Pr-ester>Gly-Me-ester 순으로 나타났다.

• 공업화학
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• 제2권3호
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• pp.229-237
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• 1991

합성촉매로 triethylamine(TEA), triethylbenzyl ammonium chloride(TEBAC), cetyltrimethyl ammonium bromide(CTMAB) 등의 아민 및 chromium acetyl acetate(CAA), triphenylantimony(TPA) 등의 유기금속화합물을 사용하여 합성촉매가 비닐에스테르수지의 합성 및 물성에 미치는 영향을 연구하였다. 반응성, 경화시간, 저장안정성 등을 고려해 볼 때, 촉매의 적절한 사용량은 methacrylic acid(MAA)에 대하여 아민계의 경우에는 1.7~2.2%(중량 %), 유기금속계의 경우에는 2.5~3.1%(중량 %)였다. 촉매의 반응성은 TEA>TEBAC>CT-MAB>CAA>TPA의 순이었으며, 촉매의 온도의존성은 $110^{\circ}C$ 이상에서 크게 나타났다. 수지의 저장안정성은 합성 후 TPA를 MAA에 대하여 2.0% (중량 %) 이내의 범위에서 첨가하였을 때, 경화시간의 지연됨이 없이 개량되었다.

• 대한화학회지
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• 제9권1호
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• pp.23-28
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• 1965

90% ethanol solution에서 benzyl chloride와 radioactive chloride($^{36}Cl^-$)와의 exchange를 反應速度論的으로 硏究하였으며 그 結果로 交換反應은 typical bimolecular reaction임을 알았고 그 activation parameter들은 각기 다음과 같았다. ${\Delta}H^{\neq}$= 18.50 Kcal ${\Delta}S^{\neq}$= -22.09 e.u. 특히 本實驗 缺課와 다른 實驗結果를 綜合討論함으로써 反應速度는 attacking anion의 nuclephilic ability에 크게 관계 됨을 입증할 수 있었으며 또한 exchange reaction에 있어서 halide들의 reactivity의 순서는 bond dissociation energy의 差로써 보다는 오히려 Swain의 nucleophilic parameter(n)로써 설명함이 더욱 타당함을 알았다.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3239-3244
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• 2011

Dinuclear Ni(II)-thiophene halides, which contain linear bridging thienylenes, trans,trans-[$(PR_3)_2$(X)Ni-Y-Ni(X)$(PR_3)_2$] {X = Cl, Br; $H_2Y$ = 5,5'-dichloro-2,2'-bithiophene ($H_2bth$); $H_2tth$ = 5,5"-dichloro-2,2':5',2''-terthiophene ($H_2tth$)} were prepared by the oxidative addition of dihalobithiophene ($H_2bth$) or dihaloterthiophene ($H_2tth$) to [$Ni(COD)_2$] in the presence of tertiary phosphines. Subsequent reactions of $NaN_3$ with the dinuclear Ni(II)-thiophene chlorides gave the corresponding Ni(II)-azido complexes, trans,trans-[$(PR_3)_2(N_3)$Ni-Y-Ni$(N_3)(PR_3)_2$], whose reactivity toward trimethylsilyl pseudohalides such as trimethylsilyl isothiocyanates and cyanides was investigated. In addition, the reaction of trans-[$BrNi(PEt_3)_2-C_4H_2S-C_4H_2S$-CHO], a thienyl Ni(II) complex containing a terminal aldehyde group, with phosphonium ylide was examined.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2187-2192
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• 2011

Hydrogen peroxide plays a key role as a second messenger in the normal cellular signaling but its overproduction has been implicated in various life-threatening diseases. Peroxalate chemiluminescence is the light emission from a three component reaction between peroxalate, hydrogen peroxide and fluorophores. It has proven great potential as a methodology to detect hydrogen peroxide in physiological environments because of its excellent sensitivity and specificity to hydrogen peroxide. We developed chemiluminescent micelles composed of amphiphilic polymers, peroxalate and fluorescent dyes to detect hydrogen peroxide at physiological concentrations. In this work, we studied the relationship between the chemiluminescence reactivity and stability of peroxalate by varying the substitutes on the aryl rings of peroxalate. Alkyl substitutes on the aryl ring of peroxalate increased the stability against water hydrolysis, but diminished the reactivity to hydrogen peroxide. Chemiluminescent micelles encapsulating diphenyl peroxalate showed significantly higher chemiluminescence intensity than the counterpart encapsulating dimethylphenyl or dipropylphenyl peroxalate. Diphenyl peroxalate-encapsulated micelles could detect hydrogen peroxide generated from macrophage cells stimulated by lipopolysaccharide (LPS) and image hydrogen peroxide generated during LPS-induced inflammatory responses in a mouse.

• 한국수소및신에너지학회논문집
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• 제20권1호
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• pp.45-54
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• 2009

Reduction reactivity and carbon deposition characteristics of three oxygen carrier particles(OCN01, OCN02, OCN03) have been investigated by using hydrogen, methane, syngas, and natural gas as fuels. For all particles, the maximum conversion, the oxygen transfer capacity, and the degree of carbon deposition increased as the reactive carbon contents increased. The reduction rate and the oxygen transfer rate increased as the moles of required oxygen per input gas increased. The change of maximum conversion, reduction rate, oxygen transfer capacity, oxygen transfer rate and degree of carbon deposition for different fuels can be explained consistently by using parameters such as the reactive carbon contents and the moles of require oxygen per input gas.

• 한국응용과학기술학회지
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• 제14권1호
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• pp.95-102
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• 1997

The synthetic method of pyrazole was performed by 1,3-dipolar cycloaddition with dipolarophile instead of the reaction between diazomethane and acetylene. The cycloaddition mechanism and reactivity of 3-phenyloxadiazole derivatives with dipolarophiles was investigated. In order to investigate the mechanism and reactivity of this cycloaddition, the effect of substituents having various kinds of electron withdrawing or releasing groups were examinated. Considering the effect of substituents, an electron withdrawing group attached at the 4-carbon position in 3-phenyloxadiazole derivatives decrease the reaction rate because of the lack of electron density in oxadiazole ring. The reaction rate of 3-phenyloxadiazole derivatives with dipolarophiles were more conveniently measured using UV than using a volumetric analysis which was used before. From the result of this study, it was that the cycloaddition was found to be a first-order reaction depending upon the concentration of 3-phenyloxadiazole only.

• 한국수소및신에너지학회논문집
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• 제19권4호
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• pp.348-358
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• 2008

Reduction reactivity and carbon deposition characteristics of mass produced oxygen carrier particle(OCN-650) have been investigated by using hydrogen, methane, syngas, and natural gas as fuels. For all fuels, the maximum conversion and oxygen transfer capacity increased as the temperature increase. The reduction rate and the oxygen transfer rate increased as the temperature increase for methane. However, those values showed maximum at 900$^{\circ}C$ for hydrogen, syngas, and natural gas. To explain consistently the change of maximum conversion, reduction rate, oxygen transfer capacity, oxygen transfer rate and degree of carbon deposition for different fuels, new parameters such as reactive carbon contents and require oxygen per input gas were adopted.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.772-776
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• 2008

Second-order rate constants ($k_N$) have been measured spectrophotometrically for reactions of 3,4-dintrophenyl 2-furoate (2) with a series of secondary alicyclic amines in 80 mol % $H_2O$/20 mol % dimethyl sulfoxide (DMSO) at 25.0 ${^{\circ}C}$. The Bronsted-type plot exhibits a downward curvature for the aminolysis of 2, which is similar to that reported for the corresponding reactions of 2,4-dintrophenyl 2-furoate (1). Substrate 2 is less reactive than 1 toward all the amines studied but the reactivity difference becomes smaller as the amine basicity increases. Dissection of the second-order rate constants into the microscopic rate constants has revealed that the reaction of 2 results in a smaller $k_2/k_{-1}$ ratio but slightly larger $k_1$ value than that of 1. Steric hindrance has been suggested to be responsible for the smaller $k_1$ value found for the reactions of 1, since the ortho-substituent of 1 would inhibit the attack of amines (i.e., the $k_1$ process).