• Title, Summary, Keyword: Ag/$Al_2O_3$

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Passivation of organic light emitting diodes with $Al_2O_3/Ag/Al_2O_3$ multilayer thin films grown by twin target sputtering system

  • Jeong, Jin-A;Kim, Han-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.420-423
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    • 2008
  • The characteristics of $Al_2O_3/Ag/Al_2O_3$ multilayer passivaton prepared by twin target sputtering (TTS) system for organic light emitting diodes. The $Al_2O_3/Ag/Al_2O_3$ multilayer thin film passivation on a PET substrate had a high transmittance of 86.44 % and low water vapor transmission rate (WVTR) of $0.011\;g/m^2$-day due to the surface plasmon resonance (SPR) effect of Ag interlayer and effective multilayer structure for preventing the intrusion of water vapor. Using synchrotron x-ray scattering and field emission scanning electron microscope (FESEM) examinations, we investigated the growth behavior of Ag layer on the $Al_2O_3$ layer to explain the SPR effect of the Ag layer. This indicates that an $Al_2O_3/Ag/Al_2O_3$ multilayer passivation is a promising thin film passivation scheme for organic based flexible optoelectronics.

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Poly(ethylene oxide)/AgBF4/Al(NO3)3/Ag2O Composite Membrane for Olefin/Paraffin Separation (올레핀/파라핀 분리를 위한 poly(ethylene oxide)/AgBF4/Al(NO3)3/Ag2O 복합체 분리막)

  • Jeong, Sooyoung;Kang, Sang Wook
    • Membrane Journal
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    • v.27 no.4
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    • pp.313-318
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    • 2017
  • For the separation of olefins/paraffins, $Poly(ethylene oxide)(PEO)/AgBF_4/Al(NO_3)_3/Ag_2O$ composite membranes were prepared. When $Ag_2O$ was introduced, the initial selectivity and permeance of composite membranes were observed to be 13.7 and 21.7 GPU, respectively. The increase in performance compared to the initial performance of $PEO/AgBF_4/Al(NO_3)_3$ membrane (selectivity 13 and permeance 7.5 GPU) was thought to be due to the increase of Ag ion activity due to the addition of $Ag_2O$. However, performance degradation over time was observed, which was thought to be due to the polymer matrix PEO. Since the PEO polymer could not stabilize the $Ag_2O$ particles, the $Ag_2O$ particles becmae aggregated together as the solvent evaporates, and $Ag_2O$ acts as a barrier. As a result, the permeance decreases over time.

DeNOx by Hydrocarbon-Selective Catalytic Reduction on Ag-V/γ-Al2O3 Catalyst (Ag-V/γ-Al2O3 촉매상에서 탄화수소-Selective Catalytic Reduction에 의한 질소산화물 저감)

  • Kim, Moon-Chan;Lee, Cheal-Gyu
    • Applied Chemistry for Engineering
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    • v.16 no.3
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    • pp.328-336
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    • 2005
  • In order to remove the NO contained in exhaust gas by the non-selective catalyst reduction method, the catalysts were prepared by varing the loading amount of Ag and V into ${\gamma}-Al_2O_3$. The conversion of $NO_x$ using the prepared catalysts was studied by varying the temperatures, $O_2$ concentrations and $SO_2$ concentrations using. The influence of the catalyst structure on $NO_x$ conversion was studied through the analysis of the physical properties of the prepared catalysts. In the case of $AgV/{\gamma}-Al_2O_3$ catalyst, the $NO_x$ conversion was lower than that of $Ag/{\gamma}-Al_2O_3$ at higher temperatures but higher than that of $Ag/{\gamma}-Al_2O_3$ at lower temperatures. Even though $SO_2$ was contained in the reaction gas, the $NO_x$ conversion did not decrease. Based on the analysis including XRD, XPS, TPR, and UV-Vis DRS before and after the experiments, the experimental results were examined. The results indicated that, $NO_x$ conversion decreased at higher temperatures since Ag oxide could not be maintained well due to the addition of V, whereas it increased at temperatures lower than $300^{\circ}C$ due to the catalytic action of V.

Oxidation of Ethylene over $Ag/{\alpha}-Al_2O_3Ag/SnO_2$ ($Ag/{\alpha}-Al_2O_3Ag/SnO_2$ 촉매상에서의 에틸렌 산화반응)

  • Jun Ki-Won;Chong-Soo Han;Hakze Chon
    • Journal of the Korean Chemical Society
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    • v.28 no.2
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    • pp.109-113
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    • 1984
  • The effects of various supports on the activity and the selectivity for the ethylene oxidation was investigated over$ Ag/{\alpha}-Al_2O_3$ and $Ag/SnO_2$ by Auger, EPR spectroscopy and reaction studies. The results indicate that over $Ag/SnO_2$ catalyst O- chemisorbed on $SnO_2 $participates in the complete oxidation of ethylene lowering the selectivity for the formation of ethylene oxide.

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Effect of the Alloying Elements in Ag-Cu-Zr-X Brazing Alloy on the Microstructure and the Bond Strength of $Al_2O_3$/Ni-Cr Steel Brazed Joint (알루미나/니켈크롬강 접합체의 미세조직 및 접합강도에 미치는 Ag-Cu-Zr-X 브레이징 합금성분의 영향)

  • Kim, Jong-Heon;Yoo, Yeon-Chul
    • Transactions of Materials Processing
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    • v.7 no.5
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    • pp.465-473
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    • 1998
  • The effect of alloying elements of Ag-Cu-Zr-X brazing alloy on the microstructure and the bond strength of $Al_2O_3/Ni-Cr$ brazed steel joint was investigated. The reaction layer, $ZrO_2$ (a=5.146 ${\AA}$ , b=5.213 ${\AA}$ , c=5.311 ${\AA}$ )was formed at the interface of $Al_2O_3/Ni-Cr$ steel joint by the redox reaction between alumina and Zr. The addition of An and Al to the Ag-Cu-Zr brazing alloy gave rise to changes in the thickness of the reaction product layer and the morphology of the brazement. Sn caused the segregation of Zr was decreased b Al the $ZrO_2$ layer formed at the Ag-Cu-Zr-Al alloy was thinner than that of $ZrO_2$ formed at the Ag-Cu-Zr-An alloy. The fracture shear strength was strongly dependent on the microstructure of the brazement. Brazing with Ag-Cu-Zr-Sn alloy resulted in a better bond strength than with Ag-Cu-Zr or Ag-Cu-Zr-Al alloy.

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Study for Bio HC - SCR over $Ag/Al_{2}O_{3}$ catalyst (Ag/$Al_{2}O_{3}$ 촉매를 이용한 Bio HC - SCR 연구)

  • Lee, Min-Joo;Lee, Hye-Min;Lee, Ju-Hun;Kim, Jin-Gul
    • Proceedings of the KAIS Fall Conference
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    • pp.39-41
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    • 2007
  • 자동차의 연소과정 후 발생되는 NOx를 제거하기 위하여 재생유(Bia-diesel)를 환원제로 사용하였으며, $Ag/Al_{2}O_{3}$ 를 배출가스 후처리 촉매로 사용하였다. 그에 따른 물리적 특성을 조사하고 bio-diesel 환원제의 질소산화물 제거 성능 실험을 수행하였다. 그 결과 $Ag/Al_{2}O_{3}$ 촉매계에서 최적의 Ag 담지량은 2wt% 인 것으로 나타나고, 산처리된 $Ag/Al_{2}O_{3}$ 촉매가 반응 온도$300^{\circ}C$ 에서 가장 높은 NOx 제거 전화율을 나타낸다.

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Study of EfficienCY of Hydrogen Rich Biodiesel as Reductant for HC-SCR over $Al_2O_3$ Supported Ag Catalyst ($Ag/Al_2O_3$ 촉매하의 HC-SCR에서 환원제로서 수소 풍부 바이오디젤의 반응 특성 연구)

  • Kim, Jin-Gul;Lee, Min-Ju;Lee, He-Min;Jeon, Ji-Yong;Kim, Seong-Soo;Yoo, Seung-Joon
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.3
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    • pp.232-237
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    • 2009
  • $Ag/Al_2O_3$ 촉매하에 디젤 엔진에서 배출되는 NOx를 정화하기 위하여, 수소가 풍부한 바이오디젤을 환원제로 사용하였다. Ag 전구체 함침과정에서 촉매기공이 부분적으로 폐쇄되는 것을 BET 실험을 통하여 관찰하였다. 2% $Ag/Al_2O_3$ 촉매의 형상과 조성은 산처리 과정을 거치더라도 변화하지 않는 것을 SEM과 EDXS 분석으로부터 확인하였다. $Ag/Al_2O_3$ 촉매 표면에서 생성되는 -NCO 와 -CN을 in-Situ DRIFT 방법을 사용하여 관찰하여 HC-SCR에서의 NOx 제거 반응구조를 확인하였다.

Behavior of Ag+ and Sn2+ After Reaction Between the Transparent Dielectric PbO-B2O3-SiO2-Al2O3 and Ag Electrodes (투명 유전체 (PbO-B2O3-SiO2-Al2O3 계)와 Ag 전극과의 반응에 의한 Ag+과 Sn2+의 거동)

  • Hong, Gyeong-Jun;Park, Jun-Hyeon;Heo, Jeung-Su;Kim, Hyeong-Jun
    • Korean Journal of Materials Research
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    • v.12 no.5
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    • pp.347-352
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    • 2002
  • A transparent dielectric of the $PbO-B_2O_3-SiO_2-A1_2O_3$ system which was a low melting glass has been used for PDP (Plasma Display Panel), but it has a problem which is a reaction to be occurred between a transparent dielectric layer and electrodes (Ag, ITO) after firing. This research was conducted for ion migration of $Ag^+\$ and $Sn^ {2+}$ during firing three different frits of low melting glass. The result showed that yellowing phenomena occurred through a chemical reaction between $Ag^+\$and $Sn^ {2+}$ at 550~58$0^{\circ}C$ for 20~60 min. In addition, it was confirmed that the migration of $Sn^{2+}$ from ITO electrode made a strong effect on the yellowing phenomena.

Effect of SOx on HC-SCR Kinetics over Ag/Al2O3 Catalyst (SOx 함유 HC-SCR에서 산처리 Ag/Al2O3 촉매의 반응 특성)

  • Lee, Ju-Heon;Park, Jeong-Whan;Kim, Seong-Soo;Yoo, Seung-Joon;Kim, Jin-Gul
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.5
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    • pp.714-720
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    • 2011
  • Ethanol was used as reducing agent to remove $NO_x$ exhaust from the stationary source. Pre-treatment with sulfuric acid over $Ag/Al_2O_3$ catalyst was dedicated to overcome the $SO_2$ poisoning effect. The $NO_x$ reduction experiment was performed under the simulated condition of power plant The increased surface area with higher CPSI devoted to increase de-$NO_x$ yield. De-$NO_x$ yield of the $NO_x$ exhaust containing 20 ppm of $SO_2$ increased after acid treatment with 0.7% $H_2SO_4$ over 4.0% $Ag/Al_2O_3$, where the increased dispersion of Ag found from the results of XRD and XPS was the dominant factor for the increased de-$NO_x$ yield. However, the reason for the decreased de-$NO_x$ yield with the acid treatment of higher concentration (1.0% and 2.0%) of $H_2SO_4$ was found to be due to the formation of $Ag_2SO_4$ crystallites found from XRD result. Acid-treated $Ag/Al_2O_3$ catalyst showed maximum de-$NO_x$ yield at higher temperature than non-treated $Ag/Al_2O_3$ catalyst did.

$NH_3$ oxidation using Ag-Cu/$Al_2O_3$ composite catalyst at low temperature (Ag-Cu/$Al_2O_3$ 복합촉매를 이용한 저온에서의 $NH_3$ 산화)

  • Lim, Yun-Hui;Lee, Ju-Yeol;Park, Byung-Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.2
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    • pp.313-319
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    • 2014
  • This study was performed to obtain high conversion efficiency of $NH_3$ and minimize generation of nitrogen oxides using metal-supported catalyst with Ag : Cu ratio. Through structural analysis of the prepared catalyst with Ag : Cu ratio ((10-x)Ag-xCu ($0{\leq}x{\leq}6$)), it was confirmed that the specific surface area was decrease with increasing metal content. A prepared catalysts showed Type II adsorption isotherms regardless of the ratio Ag : Cu of metal content, and crystalline phase of $Ag_2O$, CuO and $CuAl_2O$ was observed by XRD analysis. In the low temperature($150{\sim}200^{\circ}C$), a conversion efficiency of AC_10 recorded the highest(98%), whereas AC_5 (Ag : Cu = 5 : 5) also showed good conversion efficiency(93.8%). However, in the high temperature range, the amounts of by-products(NO, $NO_2$) formed with AC_5 was lower than that of AC_10. From these results, It is concluded that AC_5 is more environmentally and economically suitable.