• Title/Summary/Keyword: 산소 투과성

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Oxygen Permeation Properties of $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ Mixed-conducting Membrane (혼합전도성 $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ 분리막의 산소투과 특성)

  • Lim, Kyoung-Tae;Cho, Tong-Lae;Lee, Kee-Sung;Woo, Sang-Kuk;Park, Kee-Bae;Kim, Jong-Won
    • Journal of the Korean Ceramic Society
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    • v.38 no.9
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    • pp.787-793
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    • 2001
  • $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ membranes were fabricated by solid-state reaction. We investigated sintering behavior and oxygen permeation flux as a function of time-on-stream, temperature and upstream oxygen partial pressure. The oxygen was permeated at temperatures form 750$^{\circ}$C to 950$^{\circ}$C by mixed conducting through oxygen vacancy diffusion in the dense membrane. The oxygen permeation flux through the membrane were about 0.1ml/$cm^3{\cdot}$min at 850$^{\circ}$C. A constant time was required for reaching stable oxygen flux, and oxygen partial pressure affected the oxygen permeation fluxes.

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Oxygen Permeation and Syngas Production of La0.7Sr0.3Ga0.6Fe0.4O Oxygen Permeable Membrane (La0.7Sr0.3Ga0.6Fe0.4O 분리막의 산소투과특성 및 합성가스의 생성)

  • 이시우;이승영;이기성;정경원;김도경;우상국
    • Journal of the Korean Ceramic Society
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    • v.40 no.6
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    • pp.594-600
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    • 2003
  • L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ perovskite-type mixed conducting membranes, which could permeate oxygen selectively, have been fabricated and the microstructural features developed by varying the sintering conditions have been analyzed. The effects of surface modification and the membrane thickness on oxygen permeability have been evaluated under He/air environment. With increasing a grain boundary fraction, the overall oxygen permeability decreased. The syngas (CO+ $H_2$) has been produced by partial oxidation reaction of methane with the oxygen permeated through the membrane. Methane conversion and syngas yield have been evaluated as functions of the compositional ratio of feed gas and reaction temperature. In long-term duration test for 600 h, under C $H_4$+He/air environment, L $a_{0.7}$S $r_{0.3}$G $a_{0.6}$F $e_{0.4}$ $O_{3-}$$\delta$/ membrane showed a highly stable performance.

Separation Characteristics of Oxygen Isotopes with Hydrophobic PTFE Membranes (소수성 PTFE 막의 산소동위원소 분리특성)

  • 김재우;박상언;김택수;정도영;고광훈;박경배
    • Membrane Journal
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    • v.13 no.3
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    • pp.154-161
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    • 2003
  • We measured the permeation characteristics of water with the hydrophobic PTFE membranes dependent on water temperature to confirm the separation of oxygen isotopes using Air Gap Membrane Distillation (AGMD) and Vacuum Enhanced Membrane Distillation (VEMD). Isotopic concentrations of $H_2^{16}O$ and $H_2^{18}O$ of the permeated water vapor were measured by Diode Laser Absorption Spectroscopy. Concentrations of the heavy oxygen isotopes in the permeated water vapor were decreased. Isotope separation coefficients for the hydrophobic PTFE membranes were 1.004∼1.01 depending on the experimental conditions. We observed the effects of air in membrane pores on the oxygen isotope separation. Isotope separation coefficients for the hydrophobic PTFE membranes without air in pores are higher than those for the membrane with air in pores.

Gas and Lipid Permeabilities and Biodegradability of Poly(3-Hydroxybutyric Acid)/Chitosan Blend Film (Poly(3-Hydroxybutyric Acid)와 Chitosan 블렌드 필름의 기체 투과도, 유지 투과도 및 생분해도)

  • 김미라
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.7
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    • pp.1224-1229
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    • 2004
  • The blend films of poly(3-hydroxybutyric acid) (PHB) with chitosan were prepared and water vapor transmission rate, oxygen permeability and lipid permeability of the PHB/chitosan films were measured. Additionally, the biodegradability of the PHB/chitosan films was also evaluated. Water vapor transmission rate and oxygen permeability of the films decreased by the addition of chitosan. The addition of polyethylene glycol (PEG, plasticizer), however, increased the water vapor transmission rate and oxygen permeability of the films. In the evaluation of lipid permeability, all the films except PHB (the film made of only PHB) and PHB-P (the film made of PHB and PEG) did not permeate beef tallow for 24 hours. The consumed oxygen for PHB/chitosan films during incubation was greater than that for the control on the biodegradability determination of the films, which implies that PHB/chitosan films were degraded by the microorganisms. The higher PHB ratio of the films was, the faster biodegradation of the films occurred.

Oxygen Permeation Properties of Vanadium coated inorganic membrane (바나듐 무기막의 산소투과 특성)

  • 문상진;정지훈;홍석인
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.04a
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    • pp.54-55
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    • 1995
  • 무기막은 고분자막에 비해서 고온에서의 사용이 가능하고 구조적 안정성 등이 우수한 특징이 있다. 이러한 무기막에 촉매를 담지하거나 코팅하여 분리막의 역할과 촉매로서의 역할을 동시에 수행하는 막반응기로의 응용이 가능하다. 본 연구에서는 Redox mechanism에 의한 부분산화반응을 일으키는 촉매인 오산화바나듐을 sol-gel법으로 코팅한 무기막을 제조하여, 막내부에 오산화바나듐의 격자산소를 이용하는 부분산화 반응물이 존재할 때 선택적으로 증가하는 산소의 투과특성을 조사하였다.

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The Effect of LSC/GDC (50 : 50 vol%) Active Layers on Oxygen Transport Properties of LSCF/GDC (20 : 80 vol%) Dual-phase Membrane (LSC/GDC (50 : 50 vol%) 활성층이 LSCF/GDC (20 : 80 vol%) 복합 분리막의 산소투과 거동에 미치는 영향)

  • Cha, Da-Som;Yoo, Chung-Yul;Joo, Jong Hoon;Yu, Ji Haeng;Han, Moon-Hee;Cho, Churl-Hee
    • Membrane Journal
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    • v.24 no.5
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    • pp.367-374
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    • 2014
  • In the present study, disc-type LSCF/GDC (20 : 80 vol%) dual-phase membranes having porous LSC/GDC (50 : 50 vol%) active layers were prepared and effect of active layers on oxygen ion transport behavior was investigated. Introduction of active layers improved drastically oxygen flux due to enhanced electron conductivity and oxygen surface exchange activity. As firing temperature of active layer increased from $900^{\circ}C$ to $1000^{\circ}C$, oxygen flux increased due to improved contact between membrane and active layer or between grains of active layer. The enhanced contact would improve oxygen ion and electron transports from active layer to membrane. Also, as thickness of active layer increased from 10 to $20{\mu}m$, oxygen flux decreased since thick active layer rather prevented oxygen molecules diffusing through the pores. And, STF infiltration improved oxygen flux due to enhanced oxygen reduction reaction rate. The experimental data announces that coating and property control of active layer is an effective method to improve oxygen flux of dual-phase oxygen transport membrane.

Structure/Permeability Relationships of Polyimides for Oxygen and Nitrogen (Polyimide의 화학구조와 산소/질소의 투과특성)

  • 남세종
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.09a
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    • pp.23-38
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    • 1995
  • 고분자막에 의한 기체분리는 심냉분리법, 흡수법, 흡착법등에 비하여 에너지가 절약되며 장치가 간결하고 운전비용이 낮은 이점 때문에 여러가지 기체혼합물에 대하여 여러가지 목적으로 응용되기에 이르렀다. O$_{2}$/N$_{2}$ 분리막으로 요구되는 기본특성은 1) 높은 O$_{2}$ 투과성 2) 높은 O$_{2}$ 선택성 3) 막 형성에 충분한 기계적 강도 4) 열, 화학적으로 안정성이 있어야 한다. 그런데 투과계수 P$_{O_(2)}$와 투과선택도 P$_{O_(2)}$/P$_{N_(2)}$ 관계 Fig.2 에서 보는 바와 샅이 대체로 투과선택성은 상반관계에 있어서 polyimide는 높은 선택성을 나타내고 기계적 강도가 좋고 높은 열에 대하여 안정하기 때문에 일단 막재료로 양호한 조건을 갖추고 있으나 투과계수가 크지 않아 선택도를 크게 감소시키지 않으면서 투과계수를 향성시키려는 노력이 경주되고 있다. 따라서 polyimide의 화학구조와 투과계수, 투과선택도의 관계를 고찰하는 것은 대단히 중요하다. 특히 최근에는 polyimide의 화학구조를 계통적으로 변화 시켜가면서 구조와 투과특성을 고찰한 연구가 많으며, 이러한 연구를 총망라하여 화학구조와 투과특성을 고찰한 훌륭한 총설들이 발표되어왔다. Fig.3에는 지금까지 연구된 중요한 polyimide를 형성하는 dianhydride와 diamine의 구조식을 표시하였으며 이들 구조의 변화에 의하여 기체투과계수와 투과선택도가 어떤 영향을 받는지 고찰하고자 한다.

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Separation Permeation Characteristics of N2-O2 Gas in Air at Cell Membrane Model of Skin which Irradiated by High Energy Electron (고에너지 전자선을 조사한 피부의 세포막모델에서 공기 중의 O2-N2 혼합기체의 분리투과 특성)

  • Ko, In-Ho;Yeo, Jin-Dong
    • Journal of the Korean Society of Radiology
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    • v.13 no.2
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    • pp.261-270
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    • 2019
  • The separation permeation characteristics of $N_2-O_2$ gas in air at cell membrane model of skin which irradiated by high energy electron(linac 6 MeV) were investigated. The cell membrane model of skin used in this experiment was a sulfonated polydimethyl siloxane(PDMS) non-porous membrane. The pressure range of $N_2$ and $O_2$ gas were appeared from $1kg_f/cm^2$ to $6kg_f/cm^2$. In this experiment(temperature $36.5^{\circ}C$), the permeation change of $N_2$ and $O_2$ gas in non-porous membrane by non-irradiation were found to be $1.19{\times}10^{-4}-2.43{\times}10^{-4}$, $1.72{\times}10^{-4}-2.6{\times}10^{-4}cm^3(STP)/cm^2{\cdot}sec{\cdot}cmHg$, respectively. That of $N_2$ and $O_2$ gas in non-porous membrane by irradiation were found to be $0.19{\times}10^{-4}-0.56{\times}10^{-4}$, $0.41{\times}10^{-4}-0.76{\times}10^{-4}cm^3(STP)/cm^2{\cdot}sec{\cdot}cmHg$, respectively. The irradiated membrane was significantly decreased about 4-10 times than membrane which was not irradiated. And ideal separation factor of $N_2$ and $O_2$ gas by non-irradiation was found to be from 1.32 to 0.42 and that of $N_2$ and $O_2$ gas by irradiation was found to be from 0.237 to 0.125. The irradiated membrane was significantly decreased about 4-5 times than membrane which was not irradiated. When the operation change(cut) and pressure ratio(Pr) by non-irradiation were about 0, One was increased to the oxygen enrichment and the other was decreased to the oxygen enrichment. The irradiated membrane was significantly decreased about 4-19 times than membrane which was not irradiated. As the pressure of $N_2$ and $O_2$ gas was increased, the selectivity was decreased. As separation permeation characteristics of $N_2-O_2$ gas in cell membrane model of skin were abnormal, cell damages were appeared at cell.