• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.125-131
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• 1993

The state of water in various modified cellulose membranes such as [carboxymethyl cellulose(CMC)-gelatin] polyelectrolyte complex, methylcellulose(MC) grafted with acrylic acid(AA), [(MC-g-AA)-gelatin] polyelectrolyte complex, were determined by differential scanning calorimetric technique. The amounts of freezing(free) and nonfreezing(bound) water were estimated to determine the permeability coefficient of solutes through membranes. The state of water in membranes were influenced by the states of the composition, morphology, and their water content. The difference in diffusive permeability through the water-swollen membranes can be explained by the difference in the free and bound water content.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2959-2962
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• 2013

As the concentration of aqueous $CD_3OH$ solutions was decreased, the OD peaks in $^2H$ NMR spectra grew relative to the $CD_3$ peaks. Isotope impurity for OH groups of $CD_3OH$ and deuterium naturally present in water contributed to the OD peaks. Using these peak area data, the site-specific isotope populations of isotope enriched chemicals were measured. In addition, the method using both $^1H$ and $^2H$ NMR spectroscopy was demonstrated with neat $CD_3OH$ to measure the site-specific isotope populations. The results indicate that although it represents only ~0.015% of hydrogen isotopes, the deuterium naturally present in solvents cannot be ignored, especially when the concentration of deuterium-enriched solutes is varied. Proton/deuteron exchange between methyl and methyl/hydroxyl groups was confirmed to be negligible, while that among hydroxyl groups was detectable.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.83-86
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• 1998

1. Introduction : Low molecular harmful organics such as 1-naphthol and phenol are widely used in industries, and pose serious environmental problems. Wastewater containing low molecular harmful organics may be ejected from various sources including metal-plating industries, circuit-board manufacturing process, photographic and photo-processing industries, refineries and metal-tailing leachate. The pollution of nation harbors, waterways and ground water resources with these organics has reached critical portions, and might also give hazardous influence on human health. Micellar enhanced ultrafiltration(MEUF) is a recently developed process to remove dissolved organics and/or heavy metals present in small or trace quantities from aqueous solution. In this system, the fatal defect is leakage of surfactants especially at low concentration below CMC(critical micelle concentration), which becomes a secondary pollution. Our group proposed to use biosurfactant and polymeric micelle to solve problems mentioned above. In this study we investigated a modified MEUF using PEO-PPO-PEO (polyethyleneoxide-polypropyleneoxide-polyethyleneoxide) block copolymers for the removal of organic solutes such as 1-naphthol and phenol from aqueous wastewater. We proposed PEO-PPO-PEO block copolymers as new surfactants for forming micelles in MEUF, and investigated the solubilization characteristics and efficiency for the removal of 1-naphthol and phenol. PEO-PPO-PEO block copolymers are, environmentally mild and safe as biosurfactants.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.454-458
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• 2009

Polypyrrole (PPy) nanotubes have been synthesized by chemical oxidative polymerization of pyrrole within the pores of polycarbonate membrane using the technology of diffusion of solutes. The nanotubes array prepared by the proposed method can be considered as nanoelectrode ensembles (NEEs). An amperometric uric acid sensor based on PPy NEEs has been developed and used for determination of uric acid in human serum samples. The electrode can direct response to uric acid at potential of 0.60V vs. SCE with wide linear range of $1.52{\times}10^{-6}\;to\;1.54{\times}10^{-3}\;M.\;The\;detection\;limit\;is \;3.02{\times}10^{-7}$ M. This sensor has been used to determine uric acid in real serum samples. PPy NEEs is thought of as a good application in the foreground.

• Journal of the Korean Chemical Society
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• v.39 no.11
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• pp.863-868
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• 1995

We have prepared microcolumns made of stainless steel tubing, glass-lined stainless steel tubing, and silica-lined stainless steel tubing and examined their performances comparatively. The length of columns was fixed as 30 cm, and the I.D.'s, either 1 mm or 0.5 mm. Octadecyl bonded silica paticles $(5\mu)$ were used as the stationary phases. p-Nitroaniline, N,N-dimethyl-o-nitro-p-toluidine,and ethylbenzene were used as the test solutes. The glass-lined or silica-lined stainless steel columns showed better performances than the plain stainless steel column did. The number of theoretical plates over 10,000 were obtained even for the 0.5 mm I.D. (30 cm long) column as long as the glass-lined stainless steel tubing was used.

• KSBB Journal
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• v.15 no.5
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• pp.497-500
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• 2000

Liposomes and proteoliposomes, artificial membranes, can interact with many solutes, such as drugs, peptides and proteins. The immobilization of (prot대)liposomes as supramolecular aggregates on gold surfaces have potential applications in nano and biosensor technology. We demonstrated a quartz crystal analyzer (QCA) based method to monitor the construction of multi-layers of unilamellar liposomes based on avidin-biotin binding on gold surfaces using a quartz crystal microbalance (QCM). Thus, the QCA provides an on line and efficient method of detecting the construction of protein membranes, which has applications in biosensing systems.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.555-562
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• 2006

Recently, liquid chromatography (LC) has been used more frequently to separate drugs and natural substances. Especially, to selection of the solutes from the products, the operation condition of analytical chromatography should be necessarily determined. So accurate computer modeling and simulation of chromatographic performances has become a necessary part of the development and design of processes. High-Purity Separation Lab. Inha University developed the resulting HCI software for the purpose of the optimization of chromatographic performances. The HCI program was utilized to find the optimum operating condition more accurately and rapidly, reducing the number of many possible experiments. The elution profiles were calculated by the plate theory based on the three retention mechanism of capacity factor.

• Resources Recycling
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• v.12 no.3
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• pp.38-45
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• 2003

ionic equilbria of nickel chloride in hydrochloric acid solutions were analyzed by considering chemical equilibria, mass and charge balance equations. The activity coefficients of solutes were calculated by using Bromley equation. It was found that most of species containing nickel existed as $Ni^{2+}$ 와 $NiCl^{+}$. The mole fractions of nickel hydroxides were very low in the con-centration ranges considered in this study and the mole fraction of$Ni_4$ $(OH)_{4}^{4+}$ increased greatly with the pH of the solution. The pH values of $NiCl_2$ $-HCl-NaOH-H_2$O system at $25^{\circ}C$ calculated in this study agreed well with those experimentally measured up to ionic strength of 9.4m.

• Polymer(Korea)
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• v.28 no.4
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• pp.352-359
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• 2004

Membrane technology was used for the optical resolution of the various racemic compounds such as tryptophan, tyrosine and phenylalanine, using enantioselective membranes prepared from sodium alginate (SA) and glutaraldehyde as a membrane material and crosslinking agent, respectively, The chemical structure of the membranes was characterized with FT-IR spectrophotometry and 3D molecular structure modeling study was done to figure out the optical resolution mechanism through the membrane. Effects of degree of crosslinking, feed concentration, operating pressure and different kinds of feed solution on the membrane performances were studied. As results, it was found that with increasing degree of crosslinking and membrane thickness, and decrease in the concentration of the feed solution and smaller size of solutes, the enantinselectivity of the membrane was improved. When the sodium alginate membranes with 80% of swelling index and 79${\mu}{\textrm}{m}$ of thickness were used, 77% of enantiomeric excess was obtained.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.280-282
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• 2018

Pseudoalteromonas sp. meg-B1 belonging to Gammaproteobacteria was isolated from marine sediment in Jeju island. Here, we report the draft genome sequence of strain meg-B1 with a size of approximately 4.15 Mbp and a mean G + C content of 41.2%. The draft genome included 3,606 coding sequences, and 9 ribosomal RNA and 94 transfer RNA genes. In the draft genome, genes (e.g. choline dehydrogenase) involved in the accumulation of compatible solutes required for survival in marine environments have been identified.