• Membrane Journal
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• v.3 no.3
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• pp.108-116
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• 1993

In PVC/PS pelyblend laminated membranes, perrneabilities were increased as increasing the blend ratio of PS and selectivities were increased with increasing the blend ratio of PVC. The gas permeation mechanism was shifted from the combination of Poiseuille and Knudsen flow model to the solution-diffusion model as decreasing the PS blend ratio. The structure of polyblend laminated membranes showed series model, where PS rich phase was formed at air side and PVC rich phase was at water side. The model of permeation in the polyblend laminated membranes also showed series model structure.

• Proceedings of the Membrane Society of Korea Conference
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• 1992.10a
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• pp.5-6
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• 1992

무기막은 고분자 계통의 유기막과는 달리 200$\circ$C 이상의 고온에서도 높은 기체 투과도와 구조적 안정성을 보인다. 따라서 무기막을 고온의 촉매 반응에 이용하면 생성물 중 일부를 선택적으로 분리시키므로써 열역학적으로 예측할 수 있는 값 이상의 높은 전환율을 얻을 수 있으며, 또한 반응물 중 일부를 막을 통해 주입하면 반응의 정도를 조절함으로써 원하는 생성물의 수율을 높일 수 있게 된다. 그러나, 현재 실험실에서 많이 연구되고 있는 다공성 유리 또는 다공성 알루미나와 같은 무기막들은 기체 투과도는 높은 반면에 기체 분리가 Knudsen diffusion에 의해 이루어지기 때문에 분리선택도가 낮은 단점이 있다.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.37-39
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• 1998

1. 서론 : 최근 낮은 에너지 소비, 적은 투자설비비로 인하여 분리기술 분야에 분리막을 적용시키는 연구가 활발히 진행되고 있으며 상업화 추진도 진행중에 있다. 특히 기체 분리 시장에서 분리막의 이용이 연구되고 있으나, 일반적인 분리막들이 가지고 있는 공통적인 특징인 투과도가 높아지면 선택도가 낮아지고, 반대로 선택도가 높아지면 투과도가 낮아지는, trade-off현상으로 인하여 분리막의 사용에는 많은 제약이 따르게 되었다. 따라서 이를 방지하기 위한 연구가 진행중이며 그로부터 얻은 결과중 하나가 6FDA를 이용한 polyimide 분리막의 적용이다.(생략)

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.619-626
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• 2007

It is of special interest in our membrane separation technology due to its low energy consumption and cost, relatively simple equipment, low investment and operation cost, et al. Full scale utilization of such processes can be widely utilized to the various fields. Using the difference of permeability of gas molecules between the filter layers, it is able to separate effectually pure gases from the mixed gases. In this paper, the membranes of PDMS, ${\gamma}-radiated$ PDMS, PTFE, PTFE-X are chosen to develop the predictive model for the separation of pure gases such as oxygen, nitrogen, hydrogen, and other gases from mixed gases. By utilizing the thermodynamic gas properties($\sigma$, $\varepsilon/k$) and experimental data of gas transport characteristics for different polymer membranes, it is able to develop the predictive model equation under the influence of temperature, pressure and polymer characteristics. Predictive model developed in this research showed good agreement with experimental data of gas permeability characteristics for develop four different polymer membranes. The proposed model can also be extended to the general equation for predicting the separation of gases based on the properties of polymeric membranes.

• Membrane Journal
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• v.32 no.1
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• pp.74-82
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• 2022

The objective of this work was to investigate the gas permeation properties of CO₂ and CH₄ for PEBAX^®/TS-530 hybrid membranes and compare with pure PEBAX^®-1657 membrane. With FTIR and XRD it was possible to confirm that TS-530 was dispersed well in PEBAX^® matrix. Compared with pure PEBAX^® membrane, ideal separation factor for PEBAX^®/TS-530 (10 wt%) hybrid membrane was enhanced a little. As the amount of TS-530 was increased, the gas permeability coefficients of both CO₂ and CH₄ were increased, while the ideal separation factor was decreased. This results were explained by the reduction of crystallinity of polyamide block and interchain distance caused by introduction of inorganic nanoparticles. And fumed silica might tend to agglomerate, resulting in forming nonselective nanogaps in the hybrid materials, thus the diffusivity would be enhanced at the expense of diffusivity selectivity.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.413-420
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• 2015

PTMSP-ZIF composite membranes were prepared by the addition of zeolitic imidazolate framework (ZIF-8) into poly (1-trimethylsilyl-1-propyne) (PTMSP) having high gas permeability to improve trade-off relationship of the polymer membrane. PTMSP-ZIF composite membranes were prepared with different amounts of ZIF-8; 0, 5, 10, 20, 30 and 40 wt%. Gas permeation properties for $H_2$, $N_2$, $CO_2$, and $CH_4$ were investigated by increasing the amount of ZIF-8 in the PTMSP. The gas permeability of PTMSP-ZIF composite membranes within 5~30 wt% of ZIF-8 contents increased as ZIF-8 contents went up and decreased thereafter. The gas permeability for $CO_2$ showed the maximum value of 76080 barrer at 30 wt% of ZIF-8 content and PTMSP-ZIF composite membrane containing 20 wt% of ZIF-8 content had the highest selectivity ($CO_2/N_2$) with the value of 8.2. The selectivity ($H_2/N_2$) and selectivity ($CO_2/CH_4$) were almost the same as PTMSP in the range 10~40 wt% of the ZIF-8. Overall, PTMSP-ZIF composite membranes resulted in maintained selectivity and increased permeability compared to those of PTMSP membranes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.699-706
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• 2018

The permeation properties of plasma polymer membranes were studied for permanent gases such as He, $H_2$, $O_2$, $N_2$, $CH_4$ and condensable vapors such as $CO_2$, $C_2H_4$, $C_3H_8$. The plasma polymers were prepared by the discharge of microwave or radiofrequency(RF) wave. Hexamethyldisiloxane (HMDS) vapor was used as a monomer for plasma polymerization. In HMDS plasma-polymerized membranes prepared under microwave discharge, the permeability coefficient was dependent of the kinetic molecular diameter of the permeate gases. Additionally the membranes showed higher $O_2/N_2$ permselectivity compared to the plasma polymers from radiofrequency discharge. On the contrary, in the HMDS plasma-polymerized membranes prepared under radiofrequency discharge, the permeability coefficient was dependent of the critical temperature of the permeant gases. The membranes showed high selectivities of $C_2H_4$ and $C_3H_8$ over $N_2$. The permeability coefficient of plasma polymerized membranes prepared under microwave discharge was dependent of the molecular diameter of permeant gases because of high crosslinking density of the membrane. However, the crosslinking density of the plasma polymerized membranes prepared under RF discharge was lower because the energy density of RF wave is weaker than that of microwave. Hence, the permeability of RF plasma polymerized membranes became dependent of the critical temperature rather than molecular diameter of the gases.

• Membrane Journal
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• v.21 no.4
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• pp.307-320
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• 2011

Polymeric gas separation membrane is the fastest growing field in membrane separation process. Polymeric gas separation membrane process is competitive compare to cryogenic process and pressure swing adsorption process. Aromatic polymer materials such as polysulfones, polypheneylene oxides, polycarbonates and polyimides have been used for gas separation. Recently, glassy polymer likes polyimide in aromatic polymers has been developed for achievement of high selectivity and permeability coefficients. The accurate understanding on a type and structure of polymer material is very important, because the factor that polymer material affect gas separation property. In the study, trend and the development direction on synthesis and permeation properties of polyimide is confirmed.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.19-20
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• 1994

막(Membrane)을 이용한 기체분리는 막층 네에서의 기체분자의 투과성의 차이를 이용하여 기체분리를 행하는 것으로 공기중 산소의 분리 (산소부화막 이라고도 한다), 수성가스중의 수소의 농축분리, 탄화수소가스중 이산화탄소의 분리, 그 외에 산업폐가스 (황화수소, 일산화탄소, 아황산가스 등)의 분리등이 있다. 이 중 산소부화막은 의료용 산소공급장치나 산업용 용광로의 연소효율 증진에 효과적으로 이용될 수 있으며 산업폐가스이 분리공정은 환경공학적 측면에서 활용이 가능하다.

• Journal of the Korean Electrochemical Society
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• v.11 no.4
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• pp.273-283
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• 2008

GDL(Gas Diffusion Layer) is one of the main components of PEM fuel cell. It transports reactants from the channel to the catalyst and removes reaction products from the catalyst to the channels in the flow filed plate. It is known that higher permeability of GDL can make it possible to enhance the gas transport through GDL, leading to better performance. And MEA's temperature is determined by gas and heat transport. In this paper, three dimensional numerical simulation of PEM fuel cell of parallel channel and serpentine channel by the permeability of GDL is presented to analysis heat and mass transfer characteristics using a FLUENT modified to include the electrochemical behavior. Results show that in the case of parallel channel, performance variation with change of permeability of GDL was not so much. This is thought because mass transfer is carried out by diffusion mechanism in parallel channel. Also, in the case of serpentine channel, higher GDL permeability resulted in better performance of PEM fuel cell because of convection flow though GDL. And mass transfer process is changed from convection to diffusion when the permeability becomes low.