• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.1-16
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• 2015

In this review, we summarized some of membrane processes using the ion exchange membrane typically used in energy applications. Ion exchange membranes are classified according to their functions, formations (e.g. heterogeneous, homogeneous), and polymer type. Furthermore, various methods to prepare cation exchange membranes and anion exchange membranes were discussed in detail and also illustrated through a thorough review of the literature works. There are numerous reports highlighting recent research trends in the ion exchange membrane fabrication, however, in this review we will focus more on discussing the development made in ion exchange membranes and their potential usages in future technologies.

• Analytical Science and Technology
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• v.11 no.4
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• pp.235-242
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• 1998

Membrane electrode based on chitin(po1y-[$1{\rightarrow}4$]-${\beta}$-N-acetyl-D-glucosamine) was prepared by mixing uniformly grounded of chitin (100 mesh) with PVC and DOS. We investigated the potential response of chitin membrane electrode to metal ions. It was observed that the response slopes for $Cd^{2+}$(34.9 mV/decade) and $Cu^{2+}$(34.0 mV/decade) were larger than those for other ions in pH 4 acetate buffer. The potentiometric response of chitin electrode to varying pH was nearly constant in the pH range of 2~12.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.61-67
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• 2005

Zeolite membranes show better thermal, mechanical, chemical stabilities than polymer membranes. Water was separated from water/ethanol mixtures by pervaporation using the NaA and the NaY zeolite membranes synthesized in our laboratory. The effects of concentration of ethanol at the feed side and temperature were studied on the permeation flux and separation factor of water. The separation factors obtained with the NaA zeolite membrane was found to be 1000 times higher than those obtained with the NaY. However, the water flux through the NaA zeolite membrane was observed to be lower than 1/2 of that through the NaY zeolite membrane.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.18-21
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• 1996

Virus and DNA removal in bio-drug manufacturing processes has received a great deal of attention in recent years. Removing of a virus using a membrane process is a promising method, because inactivated virus can be removed from the bio-drug and the process can be used as an additional and security inactivation after the method of general heat-inactivation of the virus in the bio-drug. The FDA and the biopharmaceutical industry have recently announced strict guidelines for impurities of virus and DNA contamination. The regulatory guidelines on residual amounts of DNA in mammalian cell culture products require DNA contamination of less than 100 pg/dose. Therefore, permeation and rejection of DNA through the porous membranes have become important in the application of DNA removal in bio-drug manufacturing using membrane technology. In this study, the permeation of DNA and chromatin through regenerated cellulose hollow fibers that have a mean pore diameter of 15 nm was investigated.

• Membrane Journal
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• v.26 no.1
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• pp.38-42
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• 2016

Polyvinylpyrrolidone (PVP), which is glassy polymer to have amide functional group, was induced to fabricate the facilitated olefin transport membranes for olefin/paraffin separation. Separation performance for the mixed gas consisting of propylene and propane (50 : 50 vol%) was measured by gas chromatography and bubble flow meter. The properties of membranes were confirmed by scanning electron microscope and FT-IR. The results of long-term separation tests showed the selectivity of 15 and permeance of 1.3 GPU. The membranes was compared with poly(2-ethyl-2-oxazoline) $(POZ)/AgBF_4/Al(NO_3)_3$ membranes and the characteristics were confirmed as polymer matrix for facilitated transport membranes.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.337-343
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• 2013

Membrane reactors have been showing a promising future and attracted increasing attention in the scientific community as they possess advantages in terms of enhanced catalytic activity and selectivity, combination of processes (reaction and separation), simplicity in process design, and safety in operation. In particular, solid electrolyte membrane reactor principles are realized in fuel cells, electrolyzers and reactors for hydrogenation of carbon dioxide and other economically viable reactions. In this review, as a young generation of ion conducting materials, high temperature proton conductors are discussed in terms of the current status of material development and their various applications.

• BMB Reports
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• v.33 no.1
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• pp.54-58
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• 2000

Recent research results regarding the very long chain transmembrane ${\alpha},{\omega}-dicarboxylic$ components in the membrane of extremophilic eubacteria, such as Sarcina ventriculi, Thennotoga maritima, and Thermoanaerobacter ethanolicus have raised interesting questions concerning the physical and biochemical function on these components in the membrane. In order to understand the dynamic characteristics of these acids which reside in the bilayer membrane, 580 ps molecular dynamic simulations at 300 K were performed for two model systems. These systems were the bilayer with regular chain (C16:0 or C18:1) fatty acid methyl esters and the fatty acid bilayer containing very long chain transmembrane dicarboxylic acid methyl esters (${\alpha},{\omega}-15,16-dimethyltriacotane-dioate$ dimethyl ester; C32:0). Our analyses indicate that very long chain transmembrane dicarboxylic acids have a noticeable influence on the bilayer dynamics at a sub-nanosecond time scale. The center-ofmass mean-squared-displacement (MSD) of regular chain fatty acids adjacent to the very long chain transmembrane dicarboxylic acids decreased, the long-axis order parameter increased, and the reorientational motions of methylene groups were slowed along the hydrocarbon chains. These results indicate that the very long chain transmembrane dicarboxylic acids reduce the molecular order of the whole bilayer membrane.

• Mycobiology
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• v.29 no.1
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• pp.15-18
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• 2001

Protoplast fusion is a useful technique for establishing fungal hybrids to overcome the natural barriers. The ultrastructure of protoplast and its fusion process were observed using a scanning electron microscopy(SEM) and a transmission electron microscopy(TEM). The protoplasts were variable in size from $0.5{\sim}15{\mu}m$ in diameter, and the mean diameter was about $3{\sim}5{\mu}m$. It was impossible to discriminate protoplasts of Lentinula edodes from protoplasts of Coriolus versicolor by size and surface structure. Big aggregates of the dehydrated protoplasts were observed, after polyethylene glycol 4000 treatment. Nucleus, mitochondria, lipid granules and various vesicles having granules were scattered in the cytoplasm. The vesicles were heterogeneous in size and vary from one protoplast to another. The fused membrane layer of the two protoplasts was observed. Time protoplast membrane contact and reorganization of membrane components were essential condition for protoplast fusion. Transmission electron micrograph showed fused protoplasts and flattening of the cells in the area of the membrane contact. We hope that our electron microscopic observations provide some insights into the understanding of the fusion process of protoplast in fungi.

• Applied Chemistry for Engineering
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• v.25 no.2
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• pp.198-203
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• 2014

In this study, steam reforming reaction and surface characteristics of Ni metal foam plate were investigated. Valence state of Ni could be changed by pretreatment, and metallic Ni species exposed on surface as a active site play important role in steam reforming reaction. Porous catalytic membrane also was prepared by mixing of Ni metal foam plate and Ni-YSZ catalyst to control the pore size and assign the catalytic function in Ni metal foam plate. In SEM analysis results, Pore size of Ni metal foam plate could be controlled and Ni-YSZ catalyst well dispersed on surface. Ni based porous catalytic membrane had a similar steam reforming activity regardless of space velocity.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.3088-3092
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• 2013

A novel PVC membrane sensor for perindopril based on perindopril-phosphotungstate ion pair complex was prepared. The influence of membrane composition (i.e. percent of PVC, plasticizer, ion-pair complex, and kind of plasticizer), inner solution, pH of test solution and foreign cations on the electrode performance was investigated. The optimized membrane demonstrates Nernstian response ($30.9{\pm}1.0$ mV per decade) for perindopril cations over a wide linear range from $9.0{\times}10^{-7}$ to $1{\times}10^{-2}$ M at $25^{\circ}C$. The potentiometric response is independent of the pH in the range of 4.0-9.5. The proposed sensor has the advantages of easy preparation, fast response time. The selectivity coefficients indicate excellent selectivity for perindopril over many common cations (e.g., $Na^+$, $K^+$, $Mg^{2+}$, $Cu^{2+}$, $Ni^{2+}$, rhamnose, maltose, glycine and benzamide. The practical applications of this electrode was demonstrated by measuring the concentrations of perindopril in pure solutions and pharmaceutical preparations with satisfactory results.