• 한국막학회:학술대회논문집
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• 한국막학회 2005년도 추계 총회 및 학술발표회
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• pp.152-156
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• 2005

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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• pp.30-30
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• 2002

• Korean Chemical Engineering Research
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• 제51권2호
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• pp.195-202
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• 2013

본 연구에서는 Titanium(IV) sulfate($Ti(SO_4)_2$)와 암모니아수로부터 수열합성법을 이용하여 비교적 낮은 합성온도($80{\sim}100^{\circ}C$)와 상압에서 소성과정을 거치지 않고 $TiO_2$ 분말을 제조하였고, $TiO_2$ 제조 시 반응온도, 반응물의 초기농도, 혼합용액의 pH와 같은 반응조건에 따른 $TiO_2$ 입자의 결정구조와 입자분포, 형상 등과 같은 물리적 특성을 고찰하였다. 제조한 시료는 UV 조사 하에 Brilliant Blue FCF(BB-FCF)의 광분해 실험을 실시하여 광분해 성능과 DRS 분석을 통해 광촉매 활성을 비교하였다. 제조한 시료의 물성은 XRD, SEM, PL, 입도분포 측정을 통하여 확인하였다. Titanium(IV) sulfate($Ti(SO_4)_2$)의 초기농도가 증가할수록 $TiO_2$의 평균 입자크기와 결정화도는 증가하였고 광촉매 활성은 감소하였다. 혼합용액의 pH가 높을수록 평균 입자크기는 감소하였고 광촉매 활성은 증가하였다. 반응온도가 높을수록 결정화도와 광촉매 활성은 증가하였다. 이상의 결과들로부터 $Ti(SO_4)_2$와 암모니아수를 이용한 비교적 낮은 합성온도와 상압에서의 수열합성법으로도 순수한 anatase 결정구조의 $TiO_2$가 제조됨을 확인할 수 있었다.

• Korean Chemical Engineering Research
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• 제55권6호
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• pp.785-790
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• 2017

To collect zinc, Fe and Zn in spent pickling solution were extracted by using TBP (tributyl phosphate), and Zn was recovered from extracted solution to zinc oxalate particles by oxalic acid solution. The reusability of TBP solvent was also tested. The distribution coefficient of Zn was not affected by the concentration of Fe in spent pickling solution, almost constant with the values of 7.12~9.31 when extracted by TBP solvent. It was found that the extraction capacity of TBP solvent for Zn is higher than that for Fe. The extraction efficiency of Zn was higher than 95%, while most of Fe was left in aqueous phase. After the recovery, the used TBP solvent could be repeatedly reused for the extraction of Zn up to eight times. XRD analysis showed that zinc oxalate ($ZnC_2O_4$ $2H_2O$) was formed from the reaction of Zn-TBP and oxalic acid. From the results of SEM analysis, the formation of zinc oxalate particle was strongly affected by the concentration of oxalic acid. In summary, Zn in spent pickling solution was successfully separated and recovered with TBP solvent and oxalic acid solution, respectively.

• Korean Chemical Engineering Research
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• 제48권1호
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• pp.75-79
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• 2010

에틸렌디아민테트라아세트산, 구연산 및 $NH_4Cl$ 융제가 첨가된 분무용액으로부터 분무열분해법에 의해 얇은 막 구조의 전구체 분말들을 합성하였다. $1,200^{\circ}C$에서 소성 과정을 거친 유기 첨가제와 융제를 사용하지 않은 $BaMgAl_{10}O_{17}:Eu$ 형광체는 $1{\sim}5{\mu}m$ 크기의 구형이며, 두꺼운 막 형태의 속이 빈 구조를 가졌다. 반면에 에틸렌디아민아세트산과 구연산을 첨가하여 합성된 BAM:Eu 형광체는 판상 구조의 미세한 크기를 가졌다.$NH_4Cl$ 융제의 첨가량이 0, 6, 35 wt%일때 합성된 미세 형광체들의 결정자 크기는 각각 23, 35, 33 nm였다. 최대의 발광 세기를 나타내는 최적의 융제 첨가량은 형광체의 35 wt%였으며, 융제를 첨가하지 않은 분무용액으로부터 합성된 형광체의 발광 세기의 215%였다.

• Korean Membrane Journal
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• 제8권1호
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• pp.31-35
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• 2006

Pervaporation of water/2,2,2-trifluoroethanol (TFEA) mixtures was performed using a NaY zeolite membrane which was prepared by a hydrothermal synthesis. Pervaporation with a zeolite membrane is one of the economic separation technologies for liquid mixtures including organic/water solutions. The effects of a TFEA feed concentration and a temperature were studied on the permeation flux and the separation factor. Not only the water flux increased significantly with the increase of the operating temperature, but also the TFEA flux through the NaY zeolite membrane rapidly increased with the increase of the temperature at the feed concentration below 0.8 mole fraction of TFEA.

• 대한화학회지
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• 제59권2호
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• pp.148-155
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• 2015

결정핵-매개 소프트-용액 방법을 이용하여 판상형 ZnO 나노입자를 합성하였다. 합성된 판상형 ZnO 나노입자는 많은 결함이 존재하는 (0001)면이 발달하여 상업적인 ZnO 나노입자 보다 광촉매 특성이 우수하였다. 또한, 판상형 ZnO 나노입자의 세포독성이 실리카 코팅을 통해 감소함을 확인하였다. 마지막으로 판상형 ZnO를 합성하는데 필요한 성장용액의 다양한 시약 조건들을 변화시키면서 상업적인 적용이 가능한 수백 그램 스케일로 대량합성 하는데 처음으로 성공하였다.

• 제어로봇시스템학회논문지
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• 제9권6호
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• pp.473-477
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• 2003

An immersion-type on-line refractometer useful for the in-situ measurement of chemical composition and temperature is developed, and its performance is examined by applying the refractometer to known alcohol solution having concentrations between 0 vol. % and 25 vol. %. Because refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for fast and direct measurement. The outcome of composition measurement for the different concentrations of alcohol solution indicates that the device is suitable for the chemical composition measurement by yielding stable and reproducible reading.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.213-217
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• 2005

Microbial hydrogel was prepared with poly(${\gamma}$-glutamic acid) produced from Bacillus subtilis BS62 using crosslinking reagent, ethylene glycol diglycidyl ether (EGDE), and its physico-chemical characteristics were examined. Hydrogel which prepared from 10 grams of 10% PGA solution with $600\;{\mu}l$ of EGDE at $50^{\circ}C$ for 17 h swelled 4,320 times its dry weight, and time to reach swelling equilibrium in deionized water at 4 to $45^{\circ}C$ range was about 20 h. Swollen hydrogel shrunk in ionic solutions, and rate of shrinkage was higher in calcium chloride solution than sodium chloride solution. Swelling rate of hydrogel increased 1.3-fold of initial swelling rate for 30 min at $80^{\circ}C$.

• 한국연소학회지
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• 제13권1호
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• pp.17-22
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• 2008

A partly implicit/quasi-explicit method is introduced for the solution of detailed chemical kinetics with stiff source terms based on the standard fourth-order Runge-Kutta scheme. Present method solves implicitly only the stiff reaction rate equations, whereas the others explicitly. The stiff equations are selected based on the survey of the chemical Jaconian matrix and its Eigenvalues. As an application of the present method constant pressure combustion was analyzed by a detailed mechanism of hydrogen-air combustion with NOx chemistry. The sensitivity analysis reveals that only the 4 species in NOx chemistry has strong stiffness and should be solved implicitly among the 13 species. The implicit solution of the 4 species successfully predicts the entire process with same accuracy and efficiency at half the price.