• 대한화학회지
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• 제34권2호
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• pp.184-188
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• 1990

치환 phenacyl bromide와 imidazole과의 반응 및 phenacyl bromide와 치환imidazole과의 반응속도를 전기전도도법으로 측정하였다. 반응속도는 phenacyl bromide의 전자 끄는기에 의하여 촉진되었으며 이 반응은 linear free energy relationship과 isokinetic relationship에 잘 맞았다. 반응속도와 imidazole의 pKa사이에는 Bronsted rule이 잘 적용되었으나 2-methylimidazole의 경우에는 위치장애현상으로 인해 여기서 벗어났다. Acetonitrile 용매하에서는 methanol 용매하에서보다 Kirkwood식에서 예상되는 것보다 훨씬 빠르게 반응속도가 관찰되었다.

• 대한화학회지
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• 제22권4호
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• pp.221-228
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• 1978

2,4-Dinitrohalo (F,Br) benzene과 파라치환아닐린간의 반응속도를 아세토니트릴-메탄올 혼합용매하에서 측정하였다. 2,4-Dinitrobromobenzene과 치환아닐간의 반응에서 메탄올은 친핵촉매 현상만을 보였으며, 2,4-dinitrofluorobenzene과 치환아닐린간의 반응에서는 메탄올은 양쪽성(친핵 및 친전자) 촉매현상을 보였다. 메탄올에 의한 친핵촉매현상은 아마도 천이상태에서 알코올기의 수소와 이탈기의 플루오르사이의 수소결합에 의해 설명될 수 있으며 친전자촉매현상은 알코올기의 산소와 아닐린의 아민기 수소사이의 수소결합에 기인되는 것임을 알았다.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3053-3056
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• 2009

The title compound, ${\alpha},{\alpha}$-dichloro-o-methylacetophenone, was prepared and its photochemical behavior was investigated. Addition of an extra chlorine at alpha position to the carbonyl showed many different features from photochemical reactivities of mono chloro analogue, 2,5-dimethylphenacyl chloride. In benzene, a rearrangement product with a formal 1,5-Cl shift and a reduction product were formed beside indanone. In methanol, solvolysis and cyclization of a common dienol intermediate occurred at comparable reaction rates.

• Bulletin of the Korean Chemical Society
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• 제2권2호
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• pp.41-45
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• 1981

For solvolyses of benzenesulfonylchlorides we determined transfer enthalpies of transition states, and solvent (TFE + EtOH) and substituent effects on rates. We have used the More O'Ferrall plots to show that transition states variation caused by solvent and substituent changes is consistent with an associative $S_N2$ mechanism for the nucleophilic substitution reaction of benzenesulfonylchlorides.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1997년도 Proceedings of the 12th KACG Technical Meeting and the 4th Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.53-60
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• 1997

The roasting of pyrite with a cyclone reactor have been studied in terms of investigating the reaction behavior of pyrite. The development of a fundamental model for pyrite oxidation and lime sulfation in a vertical cyclone reactor. The model assumes a chemical control shrinking core behavior for the pyrite and a fluid film control shrinking core behavior for the lime. The oxygen and sulphur dioxide concentrations and the energy balance for the gas, pyrite and lime particles are solved. The model was solved and characterized numerically. Experiments have been performed to study the influence of reaction parameters such as reactor temperatures, pyrite particle sizes, air flow rates, feeding rates, and mixing ratio of pyrite and lime. The oxidation and sulfation products were characterized chemically and physically.

• 한국응용과학기술학회지
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• 제9권2호
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• pp.141-148
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• 1992

Transesterification reactions (methyl methacrylate with diethanolamine, ethylene glycol with dimethylphthalate) were kinetically investigated in the presence of zinc compound catalysts at $120{\sim}170^{\circ}C$ The amount of reactants was measured by gas chromatography. and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively, The overall reaction order was 2nd. The apparent rate constant (k') was found to obey first kinetics with respect to the concentration of catalyst. It shows that according to an increase in basicity of anionic species the rate constant increase, and that a linear relationship exists between ln k and pKa in transesterification reaction of methyl methacrylate with diethanolamine.

• Korea-Australia Rheology Journal
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• 제16권1호
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• pp.35-45
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• 2004

Rates of chemical absorption of $CO_2$ in water-in-oil (w/o) emulsion were measured in a flat-stirred vessel at $25^{\circ}C$. The w/o emulsion was composed of aqueous monoethanolamine (MEA) droplets as a dispersed phase and non-Newtonian viscoelastic benzene solutions of polybutene (PB) and polyisobutylene (PIB) as a continuous phase. The liquid-side-mass transfer coefficient ($k_L$) was obtained from the dimensionless empirical equation containing Deborah number expressed as the properties of pseudoplasticity of the non-Newtonian liquid. $k_L$ was used to estimate the enhancement factor due to chemical reaction between $CO_2$ and MEA in the aqueous phase. PIB with elastic property of non-Newtonian liquid made the rate of chemical absorption of $CO_2$ accelerate compared with Newtonian liquid.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.406-409
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• 1999

Experimental Investigations were carried out to remove NOx, SOx simultaneously from simulated flue gas[NO(0.02%)-SO$_2$(0.08%)-$CO_2$-Air-$N_2$] by using a plasma chemical reaction. Ammonia gas(14.81%) balanced by argon was diluted by all and was Introduced to mall simulated flue gas duct through NH$_3$ Injection system which is in downstream of reactor. The NH$_3$ molecular ratio(MR) was determined based on (NH3) to [NO+S0$_2$]. MR is 1, 1.5, 2.5. The NOx removal rate significantly increased with increasing NaOH bubble quantity. The SO$_2$ removal rate was not significantly effected by applied voltage, however it fairly Increased with increasing NH$_3$ molecule ratio. By-product aerosol particle was observed by XRD(X-ray diffraction) after sampling, The NOx, SOx removal rates, when H2O vapour bubbled by dry all was injected to plasma reactor, were better than those of other cases. When aqueous NaOH solution(20%) bubbled by 2.5( ι /min) of $N_2$ and 0.5 ( ι /min) NH$_3$(MR=1.5) were injected to simulated flue gas, The NOx. SOx removal rate was 95 ~ 100[%]

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1341-1345
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• 2004

We developed a novel synthesis strategy of titania nanowire arrays by employing simple hydrothermal reaction and ion-exchange reaction techniques. Hydrothermal reactions of metallic titanium powder with $H_2O_2$ in a 10 M NaOH solution produced a new sodium titanate compound, $Na_2Ti_6O_{13}{\cdot}xH_2O$ (x~4.2), as arrays of nanowires of lengths up to 1 mm. Acid-treatment followed by calcination of this material produced arrays of highly crystalline anatase nanowires as evidenced by x-ray diffraction, Raman spectroscopy, and transmission electron microscopy studies. In both cases of sodium titanate and anatase, the nanowires have exceptionally large aspect ratios of 10,000 or higher, and they form arrays over a large area of $1.5 {\times} 3 cm^2$. Observations on the reaction products with varied conditions indicate that the array formation requires simultaneously controlled formation and crystal growth rates of the $Na_2Ti_6O_{13}{\cdot}xH_2O$ phase.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.76-82
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• 2012

볏짚 톱밥과 같은 바이오매스는 석탄과 함께 사용할 수 있는 잠재력이 큰 에너지원으로 이들을 가스화공정에 적용하면 수송용 연료같은 bio-oil을 생산할 수 있다. 본 연구에서는 상압의 열천칭 반응기(thermobalance)에서 톱밥, 볏짚, 갈탄, 역청탄, 무연탄의 수증기 가스화 반응특성을 수행하였으며, 가스화 온도 $600{\sim}850^{\circ}C$, 수증기 분압 30~90 kPa의 범위에서 조업변수들이 가스화반응속도에 미치는 영향을 조사하였다. 세 가지의 기체-고체 화학반응모델이 가스화반응의 거동을 예측하는 능력을 비교하였으며, modified volumetric reaction model을 사용하여 공정설계에 필수적인 kinetic 정보를 도출하였다. 두 가지 바이오매스와 세 가지 석탄 촤의 가스화반응성을 비교하였다. Arrhenius plot으로부터 얻어진 바이오매스와 석탄의 활성화에너지는 모두 문헌상의 범위에 속하였다. 각 연료에 대하여 수증기분압에 대한 반응차수를 결정하였으며, 가스화공정 설계의 기초데이타로서 겉보기 반응속도식을 제시하였다.