• Journal of Korean Association for Spatial Structures
• /
• v.16 no.2
• /
• pp.55-60
• /
• 2016

The Membrane structure has a number of problems in the application of a fireproof code based on general buildings codes. Thus, the fireproof code of membrane structure is necessary to activate the construction of the membrane structure. Because it requires a systematic classification of fire retardant and flame proof performance of membrane material. Fire retardant and flame proof tests are conducted on membrane materials mostly used in current construction to propose the fire and flame retardant performance criteria of membrane materials. Fire and flame retardant tests results, PTFE membrane material with the glass fiber fabric have a limit-combustible performance. PVDF membrane material with the polyester fabric does not ensure the fire retardant performance, but this membrane material has the flame retardant performance of a thick fabric. Also, ETFE does not ensure the fire retardant performance, but this membrane material has the flame retardant of a thin fabric.

• Korean Chemical Engineering Research
• /
• v.55 no.4
• /
• pp.473-477
• /
• 2017

The polymer membrane of proton exchange membrane fuel cell (PEMFC) has a great influence on PEMFC performance and durability. In this study, hydrogen permeability, fluorine emission rate (FER), lifetime, and performance of Nafion membranes with different thicknesses were measured to investigate the effect of thickness of polymer membrane on performance and durability. The relationship between membrane thickness and lifetime was obtained from the relationships between hydrogen permeability and membrane thickness, hydrogen permeability and FER, FER and lifetime. As the membrane became thicker, the hydrogen permeability and FER decreased and the lifetime increased. On the other hand, the performance decreased with increasing membrane resistance. The membrane thickness range satisfying both performance and durability was 25 to $28{\mu}m$.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1998.09a
• /
• pp.31-55
• /
• 1998

1. Performance of RO membrane depends on chain structure (packing density) 2. Crosslinking of main chain is essential for the high performance RO membranes 3. Various bisphenols and polyaminostyrene can be promising materials for the fabrication of RO membranes. 4. By using of blend technique of reactant, we can expect broad spectrum of RO membrane and synergetic effects in membrane performance.

• Journal of the Korean Ceramic Society
• /
• v.40 no.2
• /
• pp.118-122
• /
• 2003

The performance evaluation on Pt loading in the self-humidifying polymer electrolyte membrane for Polymer Electrolyte Mem-Brane Fuel Cell(PEMFC) was investigated by using single cell test and measurement of membrane resistance. The self-humidifying membrane comprised two membranes made of perfluorosulfonylfluroride copolymer resin and fine Pt particles tying between them, coated by sputtering. From the results of performance characteristics of self-humidifying membrane cell with different Pt loading, a single cell using self-humidifying membrane with 0.15 mg/$\textrm{cm}^2$ Pt loading showed better performance than that with the others over entire current density. Also, a single cell with 0.15 mg/$\textrm{cm}^2$ Pt loading had a lower resistance value than the other cells under externally nonhumidifying condition. It is indicated that the water produced in the membrane cell with 0.15 mg/$\textrm{cm}^2$ Pt loading showed a higher provision to maintain ionic conductivity of the membrane than the other cells. The optimum amount of Pt particles embedded in the membrane for self-humidifying PEMFC was determined to be about 0.15 mg/$\textrm{cm}^2$.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.98.2-98.2
• /
• 2011

For optimal performance of a proton exchange membrane fuel cell (PEMFC), the membrane electrode assembly (MEA) requires hydration, and the membrane's conductivity depends on water content. A humidifier is required to ensure that the reactant gas, usually hydrogen and air, is hydrated before entering the fuel cell. Dry membrane operation or improper hydration causes performance degradation. Typically, the humidification of a fuel cell is carried out by means of an internal or external humidifier. A membrane humidifier is applied to the external humidification of transportation or residential power generation fuel cell due to its convenience and high performance. In this study, The experiments were constructed with a plate-type membrane humidifier in terms of geometric parameters and operating parameters. The results show that the temperature and pressure, the channel length, the membrane thickness and gas flow rate are critical parameters affecting the performance of the humidifier.

• Membrane and Water Treatment
• /
• v.13 no.4
• /
• pp.191-199
• /
• 2022

In industrial production, the development of traditional polyamide nanofiltration (NF) membrane was limited due to its poor oxidation resistance, complex preparation process and high cost. In this study, a composite NF membrane with high flux, high separation performance, high oxidation resistance and simple process preparation was prepared by the method of dilute solution dip coating. And the sulfonated polysulfone was used for dip coating. The results indicated that the concentration of glycerin, the pore size of the based membrane, the composition of the coating solution, and the post-treatment process had important effects on the structure and performance of the composite NF membrane. The composite NF membrane prepared without glycerol protecting based membrane had a low flux, when the concentration of glycerin increased from 5% to 15%, the pure water flux of the composite NF membrane increased from 46.4 LMH to 108.2 LMH, and the salt rejection rate did not change much. By optimizing the coating system, the rejection rate of Na₂SO₄ and PEG1000 was higher than 90%, the pure water flux was higher than 40 LMH (60psi), and it can withstand 20,000 ppm.h NaClO solution cleaning. When the post treatment processes was adjusted, the salt rejection rate of NaCl solution (250 ppm) reached 45.5%, and the flux reached 62.2 LMH.

• Membrane Journal
• /
• v.13 no.4
• /
• pp.283-290
• /
• 2003

To improve membrane performance, the dead-end and Cross-flow ultrafiltration with or without ultrasound irradiation onto the membrane module were carried out using a BSA protein solution. Intermittent or continuous irradiation of ultrasound effectively suppressed the formation of fouling on membrane or removed the fouling layers from membrane. Effect of ultrasound irradiation on the enhancement of ultrafiltration performance was more increased at the operating conditions which form more membrane fouling (at the operating conditions of higher feed concentration and TMP, and lower flow rate). The permeate flukes were enhanced up to 1.9 times in case of the dead-end ultrafiltration and 1.5 times in case of the cross-flow ultrafiltration by ultrasound irradiation onto the membrane module.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.6
• /
• pp.915-922
• /
• 2008

The gas separation technology using membrane is widely used to refine various gases in many industry fields and recently is being applying in $CO_2$ recovery technology. In the gas and chemical tanker. nitrogen generators for inerting, purging and padding are on board and most of them have membrane modules of hollow fiber type with long life and vibration resisting properties. Because a membrane module is a key component accounting for 50% of total manufacturing cost of nitrogen generator, adequate selection for it is an important problem. In this paper, the flow performance coefficient based on dimension and specification data of membrane module was relatively selected to compare nitrogen generating capacity of module and various performance tests about the selected PARKER ST6010 membrane module were conducted. As a result, the useful coefficient and basic data in selecting a membrane module were achieved.

• Membrane and Water Treatment
• /
• v.8 no.6
• /
• pp.613-623
• /
• 2017

We report the novel thin film composite RO membrane modified by graphene oxide. The thin film composite RO membrane was exposed to 2000 mg/l sodium hypochloride; thereafter it was subjected to different graphene oxide concentration ranging from 50 mg/l to 1000 mg/l in water. The resultant membrane was crosslinked with 5000 mg/l N-hydroxysuccinimide. The performance of different membranes were analysed by solute rejection and water-flux measurement. It was found that 100 mg/l graphene oxide exposure followed by 5000 mg/l N-hydroxysuccinimide treatment resulted in the membrane with the highest solute rejection of 97.78% and water-flux of 4.64 Liter per sqm per hour per bar g. The membranes were characterized by contact angle for hydrophilicity, scanning electron micrographs for surface morphology, energy dispersive X-Ray for chemical composition of the surface, Atomic force microscope for surface roughness, ATR-FTIR for chemical structure identification. It was found that the graphene oxide modified membrane increases the salt rejection performance after exposure to high-fouling water containing albumin. Highly hydrophilic, antifouling surface formation with the nanomaterial led to the improved membrane performance. Moreover, the protocol of incorporating nanomaterial by this post-treatment is simple and can be applied to any RO membrane after it is manufactured.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1994.04a
• /
• pp.51-52
• /
• 1994

High permeability, selectivity and stability are the basic properties also required for membrane gas separations. The $CO_2$ separation by liquid membranes has been developed as a new technique to improve the permeability and selectivity of polymeric membranes. Sirkar et al.(1) have atlempted the hollow-fiber contained liquid membrane technique under four different operational modes, and permeation models have been proposed for all modes. Compared to a conventional liquid membrane, the diffusional resistance decreased by the work of Teramoto et al.(2), who referred to a moving liquid membrane. Recently, Shelekhin and Beckman (3) considered the possibility of combining absorption and membrane separation processes in one integrated system called a membrane absorber. Their analysis could be predicted effectively the performance of flat sheet membrane, however, there are restrictions for considering a flow effect. The gas absorption rate is determined by both an interfacial area and a mass transfer coefficient. It can be easily understood that although the mass transfer coefficients in hollow fiber modules are smaller than in conventional contactors, the substantial increase of the interfacial area can result in a more efficient absorber (4). In order to predict a performance in the general system of hollow-fiber membrane absorber, a gas-liquid mass transfor should be investigated inevitably. The influence of liquid velocity on both a mass transfer and a performance will be described, and then compared with experimental results. A present study is attempted to provide the fundamentals for understanding aspects of promising a hollow-fiber membrane absorber.