• 멤브레인
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• 제27권4호
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• pp.319-327
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• 2017

Chitosan과 Pebax[poly(ether-block-amide)의 mass ratio를 1 : 1, 1 : 2, 1 : 10, 1 : 30으로 하여 Chitosan/Pebax 복합 막을 제조하였다. 기체투과 실험은 압력 $6kgf/cm^2$ 하에서 35, 45, $65^{\circ}C$로 온도를 달리하여 진행되었고, Chitosan/Pebax 복합 막에 대한 $N_2$와 $CO_2$의 기체투과도와 선택도($CO_2/N_2$) 등을 조사하였다. $N_2$와 $CO_2$의 투과기체에 대해 Chitosan에 가해지는 Pebax의 함량이 증가할수록 $N_2$와 $CO_2$의 기체투과도는 모두 증가하였다. 선택도($CO_2/N_2$)는 Chitosan/Pebax 복합 막에서 6.9~44.3의 값을 가지며, Pebax의 함량이 증가할수록 그리고 온도가 낮을수록 큰 값을 보였다.

• 한국수소및신에너지학회논문집
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• 제14권2호
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• pp.155-170
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• 2003

$Cu-Ce/{\gamma}-Al_2O_3$ based catalysts were prepared and tested for selective oxidation of CO in a $H_2$-rich stream(1% CO, 1% $O_2$, 60% $H_2$, $N_2$ as balance). The effects of Cu loading and weight ratio(=Cu/(Cu+Ce)) upon both activity and selectivity were investigated upon the change in temperatures, It was also examined how the activity and selectivity of catalysts were varied with the presence of $CO_2$ and $H_2O$ in the reactant feed. Among the various Cu-Ce catalysts with different catalytic metal composition, Cu-Ce(4 : 16 wf%) /${\gamma}-Al_2O_3$ catalyst showed the highest activity(>$T_{99}$) and selectivities(50-80%) under wide range of temperatures($175-220^{\circ}C$). However, in the Cu-Ce(4 : 16 wt%)/ ${\gamma}-Al_2O_3$, the presence of $CO_2$ and $H_2O$ in the reactant feed decreased the activity and the maximum activity(>$T_{99}$) in terms of reaction temperature moved by about $25^{\circ}C$ toward higher temperature, the $T_{>99}$ window was seen between $210-230^{\circ}C$ (selectivity 50-75%). From $CO_2-/H_2O-TPD$, it can be concluded that the main cause for the decrease in catalytic activity may be attributed to the blockage of the active sites by competitive adsorption of water vapor and $CO_2$ with the reactant at low temperatures.

• 공업화학
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• 제26권4호
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• pp.413-420
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• 2015

기체 투과도가 우수한 PTMSP [Poly(1-trimethylsilyl-1-propyne)] 고분자막의 양립현상(trade-off relationship)을 개선하기 위해서 ZIF-8 (zeolitic imidazolate framework)을 첨가하여 PTMSP-ZIF 복합막을 제조하였다. PTMSP-ZIF 복합막은 PTMSP에 ZIF-8의 함량을 0, 5, 10, 20, 30, 40 wt%로 하여 제조하였고, PTMSP-ZIF 복합막의 ZIF-8 함량 변화에 따른 $H_2$, $N_2$, $CO_2$, $CH_4$의 기체투과 특성을 알아보았다. 기체투과 실험에서 ZIF-8의 함량 5~30 wt%까지는 ZIF 함량이 증가함에 따라 기체투과도는 증가하였고, 그 이후에는 감소하였다. PTMSP-ZIF 30 wt% 복합막에서 $CO_2$의 기체투과도가 76080 barrer로 가장 큰 기체투과도를 보였고, PTMSP-ZIF 20 wt% 복합막에서 선택도($CO_2/N_2$)는 8.2로 가장 높은 값을 보였다. 선택도($H_2/N_2$)와 선택도($CO_2/CH_4$)는 ZIF-8 함량 10~40 wt% 범위에서 PTMSP 단일막과 거의 비슷한 값을 보였다. 전체적으로 PTMSP-ZIF 복합막들은 PTMSP 단일막보다 선택도는 감소되지 않으면서 투과도는 향상된 결과를 보였다.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.3005-3012
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• 2013

The effect of Mn-promotion on high surface area Al-pillared montmorillonite (AlMMT) supported Co nanoparticles prepared by hydrothermal method have been investigated. A series of different weight% Mn-promoted Co nanoparticles were prepared and characterized by XRD, TPR, TGA, BET and SEM techniques. An increase in the surface area of MMT is observed with Al-pillaring. Fischer-Tropsch catalytic activity of the as prepared catalysts was studied in a fixed bed micro reactor at $225^{\circ}C$, $H_2/CO$ = 2 and at 1 atm pressure. The data showed that by the addition of Mn the selectivity of $C_1$ dropped drastically while that of $C_2-C_{12}$ hydrocarbons increased significantly over all the Mn-promoted Co/AlMMT catalysts. The $C_{13}-C_{20}$ hydrocarbons remained almost same for all the catalysts while the selectivity of $C_{21+}$ long chain hydrocarbons decreased considerably with the addition of Mn. The catalyst with 3.5%Mn showed lowest $C_{21+}$ and highest $C_2-C_{12}$ hydrocarbons selectivity due to cracking of long chain hydrocarbons over acidic sites of MMT.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.589-596
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• 2016

Effects of pressure, temperature, gas velocity, and fuel flow rate on reduction of three oxygen carriers, SDN70, OC-1, OC-2, were measured and investigated in a pressurized bubbling fluidized bed reactor. Among three oxygen carriers OC-2 was selected as the best oxygen carrier in view of fuel conversion and $CO_2$ selectivity. However, all oxygen carriers showed good reactivity even at high pressure conditions. SDN70 particle showed maximum reactivity at $900^{\circ}C$ and low reactivity at $950^{\circ}C$. However, reactivity decay of OC-1 and OC-2 particles at high temperature condition was negligible. The fuel conversion and the $CO_2$ selectivity slightly decreased as the gas velocity increased, whereas they are slightly increased as the fuel concentration increased.

• 멤브레인
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• 제31권6호
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• pp.404-416
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• 2021

본 연구에서는 PEBAX2533에 합성된 GO와 PEI-GO의 함량을 달리 첨가하여 혼합막을 제조하고 N₂와 CO₂의 투과 특성을 연구하였다. PEBAX/GO 혼합막의 N₂와 CO₂ 투과도는 전체적으로 GO 함량이 증가할수록 감소하였고, GO 0.3 wt%에서 가장 높은 CO₂/N₂ 선택도 58.9를 보였다. 그리고 PEBAX/PEI-GO 혼합막에서 N₂ 투과도는 PEI-GO 함량이 증가함에 따라 감소하였고, CO₂ 투과도는 PEI-GO 함량에 따라 다른 경향을 보였으며 전체적으로 PEBAX/GO 혼합막보다 더 높은 CO₂/N₂ 선택도를 보였다. 특히 PEI-GO 0.3 wt%는 혼합막들 중 가장 높은 CO₂/N₂ 선택도인 73.5를 보이며 Robeson upper bound 위에 위치하는 긍정적인 결과를 얻었다. 이는 본연의 GO 구조에 의한 molecular sieving channel 효과와 CO₂에 친화성이 있는 GO의 구조 내에 존재하는 작용기 그리고 GO를 PEI로 개질함으로써 PEI에 결합되어 있는 amine에 의한 효과가 함께 작용했기 때문으로 생각된다.

• 대한화학회지
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• 제32권5호
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• pp.501-506
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• 1988

본 연구에서는 알칼리화합물의 첨가가 Co/NaY촉매의 반응성과 선택도에 미치는 영향을 관찰하였다. 촉매는 제올라이트 NaY에 알칼리화합물을 첨가한 후 $Co_2(CO)_8$을 담지시켜 제조하였고, 온도 = 200∼$250^{\circ}C$, GHSV = 120∼$160hr^{-1}$, 압력 = 1atm, $H_2$/CO = 1 에서 반응하였다. 첨가된 알칼리이온의 염기도가 클수록 올레핀선택도, probability of chain growth(${\alpha}$), $CO_2$의 생성율은 증가하고 메탄의 생성율은 감소하였으며, 알칼리용액의 염기도가 클수록 반응활성은 증가하였다.

• Journal of Information Display
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• 제12권4호
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• pp.205-208
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• 2011

Herein, the integration of solution-processed polymer thin-film transistors (TFTs) that were fabricated using selective wettability through ultraviolet (UV) exposure into a reflective liquid crystal display is demonstrated. From the experimental results of energy-dispersive spectroscopy, the composition of carbon and fluorine enhancing the hydrophobicity in the polymer chains was found to play a critical role in the wetting selectivity upon UV exposure. The polymer TFTs fabricated through the wettability-patterning process exhibited long-term stability and reliability. This wetting-selectivity-based patterning technique will be useful for constructing different types of solution-processed electronic and optoelectronic devices.

• Bulletin of the Korean Chemical Society
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• 제10권1호
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• pp.96-101
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• 1989

The infrared multiphoton decomposition of trichloroethylene-H(TCE-H) and trichloroehtylene-D(TCE-D) was studied by using the high power $CO_2$ laser. The pressure dependence of TCE-H decomposition showed that the HCl elimination channel to form ClC ≡ CCl was the major step at high pressures, while the HC ≡ CCl formation step became important at low pressures. $Cl_2C$ = CHCl ${\rightarrow}$ (high pressure) ClC ${\equiv}$ CCl + HCl ${\rightarrow}$ (low pressure) HC ${\equiv}$ CCl + 2Cl${\cdot}$($Cl_2$) The IRMPD of TCE-H and TCE-D mixtures with 10P(20) laser line showed that optimum conditions of large isotope selectivity were the low system pressures and high laser powers. The experimentally observed dependence of the branching ratios on the pressure and laser fluence, and the isotope selectivity coefficients were quantitatively explained by using the modified energy grained master equations (EGME) model.

• 멤브레인
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• 제24권3호
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• pp.185-193
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• 2014

고무상 고분자인 PDMS (polydimethylsiloxane)에 HNT (halloysite nanotube)의 함량을 5, 10, 20, 30 wt%로 달리하여 PDMS-HNT 복합막을 제조하고, FT-IR, XRD, TGA, SEM에 의해서 막의 특성을 조사하였다. 기체투과 실험은 $25^{\circ}C$, $3kg/cm^2$ 조건에서 수행하였고, PDMS-HNT 복합막의 HNT 함량 변화에 따른 $H_2$, $N_2$, $CH_4$, $CO_2$들의 기체투과도와 선택도를 조사하였다. $H_2$, $N_2$, $CH_4$, $CO_2$의 투과기체에 대해 HNT 함량이 0~30 wt% 범위에서 HNT 함량이 증가할수록 기체들의 투과도는 전체적으로 감소하는 경향을 보였다. 선택도($CO_2/N_2$)는 14~44의 값을 보였고, 선택도($CO_2/CH_4$)는 3.0~7.7의 값을 보였다.