• Proceedings of the Membrane Society of Korea Conference
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• 2001.05a
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• pp.108-111
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• 2001

• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.49-52
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• 2003

• Proceedings of the Membrane Society of Korea Conference
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• 1999.10b
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• pp.31-32
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• 1999

• Proceedings of the Membrane Society of Korea Conference
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• 2001.11a
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• pp.38-41
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• 2001

• Proceedings of the Membrane Society of Korea Conference
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• 2000.11a
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• pp.39-42
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• 2000

• Macromolecular Research
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• v.16 no.5
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• pp.457-466
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• 2008

The relation between the phase separated morphologies and their transport properties in the polymer blend membrane for direct methanol fuel cell application was studied. In order to enhance the proton conductivity and reduce the methanol crossover, sulfonated poly(arylene ether sulfone) copolymer, with a sulfonation of 60 mol% (sPAES-60), was blended with nonsulfonated poly(ether sulfone) copolymer (RH-2000, Solvay). Various morphologies were obtained by varying the drying condition and the concentration of the casting solution (10, 15, 20 wt%). The transport properties of proton and methanol molecule through the polymer blend membranes were studied according to the absorbed water. AC impedance spectroscopy was used to measure the proton conductivity and a liquid permeability measuring instrument was designed to measure the methanol permeability. The state of water in the blend membranes was confirmed by differential scanning calorimetry and was used to correlate the morphology of the membrane with the membrane transport properties.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.2
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• pp.32-37
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• 2017

The purpose of this study was (1) to demonstrate the anti-microbial properties of 4-hexylresorcinol (4HR) loaded silk mat and (2) comparison of bone formation between 4HR incorporated silk mat and collagen membrane. Anti-microbial properties of 4HR incorporated silk mat was done after sterilization of silk mat (autoclaving and ethylene oxide gas). For the evaluation of bone formation, bilateral bony defects (size: 8 mm) were prepared in the parietal bone of the rabbits (n=10). 4HR incorporated silk mat (size: $10{\times}10mm$) was applied on the right defect. For the comparative purpose, the same size of commercial collagen membrane was applied on the left defect. The anti-microbial properties of 4HR incorporated silk mat were maintained after sterilization process. When compared bone mineral density and bone volume, there was no statistically significant difference between groups at 4 weeks and 8 weeks after operation (p>0.05). In conclusion, 4HR incorporated silk mat could be autoclaved without concern of anti-microbial properties loss. In addition, 4HR incorporated silk mat showed similar bone regeneration to collagen membrane. Therefore, 4HR incorporated silk mat might be considered for the application of open membrane technique.

• Membrane and Water Treatment
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• v.11 no.2
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• pp.159-166
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• 2020

In this study, the performance and antifouling properties of polysulfone (PSf) and polyvinylidene fluoride/polyvinylpyrrolidone (PVDF/PVP) membranes in a membrane bioreactor (MBR) were investigated. The membranes were prepared via phase inversion method, and then characterized by a set of analyses including contact angle, porosity and water flux and applied in a lab-scale MBR system. Soluble microbial product (SMP), extracellular polymeric substance (EPS), FTIR, gel permission chromatography (GPC) and particle size distribution (PSD) analyses were also carried out for MBR system. The results showed that the MBR with PSf membrane had higher hydrophobic organic compounds which resulted in formation of larger flocs in MBR. However, in this MBR had high compressibility coefficient of cake layer was higher (n=0.91) compared to MBR with PVDF/PVP membrane (n=0.8); hence, the fouling was more profound. GPC analysis revealed that compounds with molecular weight lower than 2 kDa are more formed on PSf membrane more than PVDF/PVP membrane. The results of FTIR analysis confirmed the presence of polysaccharide and protein compounds on the cake layer of both membranes which was in good agreement with EPS analysis. In addition, the results showed that their concentration was higher for the cake on PSf membrane.

• Membrane Journal
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• v.30 no.5
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• pp.283-292
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• 2020

Various kind of solutions need to be separated, purified, and concentrated using membranes in the field of industries. However, when the solution contains strong acids, the use of membrane is limited. Acid resistant membrane currently available in market does not show high efficiency of flux. This review explains the causes and mechanisms of changes in surface properties and performance of polyamide membranes when exposed to acidic solutions, and this can be used in the development of a membrane with acid resistance and high flux.

• Korean Membrane Journal
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• v.10 no.1
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• pp.13-19
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• 2008

Water softening is a very promising field for membranes and especially ultra low pressure membranes. Nanofiltration membranes based on pore-filling technology was prepared by using a new technique: the in-situ cross-linking. This route involves introducing a pre-formed polymer into the pores of a host membrane and then locking the polymer in the pores by in-situ cross-linking with an appropriate reagent. By this way, it is possible to make robust and competitive, pore-filled, anion-exchange membranes with excellent control over the properties of the incorporated gel without affecting the host membrane. In this paper, the possibilities of tuning such membranes for ultra low pressure water softening was examined by altering pore-filling chemistry (by changing cross-linking and aminating reagents). The results showed that tuning the chemistry of the pore-filling has important effects. In particularly, it had been shown that the correct selection of cross-linking reagent was not only essential to get pore-filled membranes but it could control their properties. Moreover, the aminating reagent could improve membrane performance. It was found that an increase in hydrophobicity could improve the Darcy permeability.