• Korean Journal of Microbiology
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• v.21 no.2
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• pp.86-94
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• 1983

Polygalacturonase of Byssochlamys fulva was purified and characterized. Specific activity increased from 2.21 units/mg protein to 10.47 units/mg protein through $(NH_4)_2SO_4$ treatment, SephadexG-100 gel filtration, and DEAE-Sephadex ion exchange chromatography. Divalent cations, such as $Ca^{++}\;and\;Cu^{++}$, increased polygalacturonase activity greatly. Added as $10^{-3}M$ concentration, $Ca^{++}$ ion enhanced enzyme activity 9.8folds. Optimum temperature was $50^{\circ}C$ and optimum pH was 5.0. Activation energy of reaction was 8.69 Kcal/mole. Michaelis-Menten $constant(K_M)\;and\;V_{max}$ of reaction were $6.27{\times}10^{-3}mole/l\;and\;2.85{$\mu}moles/min$. Polygalacturonase of Byssochlamys fulva preferred polygalacturonic acid to pectin as substrate and was presumed as endo-type on the basis of the relationship between viscosity reduction and substrate degradation. Molecular weight of polygalacturonase was estimated as 55,000.

• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.1049-1051
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• 2000

A chromia-pillared clay has been prepared by ion exchange type intercalation reaction between the sodium ion in montmorillonite and the trimeric chromium oxyformate (TCF) ion, and by subsequent heat-treatment. The structural and thermal properties have been systematically studied by thermal analysis, powder XRD, IR spec-troscopy, and XAS. The gallery height of~6.8 $\AA$ upon intercalation of the TCF ion suggests that the $Cr_3O$ plane is parallel to the aluminosilicate layers. Even though the basal spacing of TCF intercalated clay decreases slightly upon heating, the layer structure was retained up to $550^{\circ}C$ as confirmed by XRD and TG/DTA. Ac-cording to the EXAFS spectroscopic analysis, it is identified that the (Cr-Cr) distance of 3.28 $\AA$ between vertex-linked CrO6 octahedra in TCF splits into 2.64 $\AA$, 2.98 $\AA$, and 3.77 $\AA$ due to the face-, edge-, and corner-shared CrO6 octahedra after heating at $400^{\circ}C$, implying that a nano-sized chromium oxide phase was stabilized within the interlayer space of clay.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.2 s.52
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• pp.159-167
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• 2004

This work has been conducted to select appropriate filter materials for removing carbonyl compounds in mainstream tobacco smoke. To investigate of the usability of this filter materials, two types of bead ion exchangers were synthesized and their adsorption characteristics for carbonyl compounds were investigated. Sulfonic acid group-containing cation exchanger and ammonium group-containing anion exchanger were synthesized by the suspension polymerization of glycidylmethacrylate(GMA) and divinylbenzene(DVB) followed by the subsequent functionalization, respectively. The removal efficiency of carbonyl compounds by these two ion exchangers increased in the presence of moisture. However, the amount of carbonyl compounds adsorbed on the anion exchanger was larger than that on the cation exchanger under two levels of water contents tested. This phenomenon seems to arise from the electron delocalization in carbonyl group of the anion exchangers. There was not any significant relationship between the amount of carbonyl compounds adsorbed on ion exchangers and the length of adsorption column. From the large ion exchange capacity and rapid ion exchange reaction rate of the anion exchanger, it is suggested that the anion exchanger may be a good filter material for removing carbonyl compounds in the mainstream tobacco smoke.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.621-626
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• 2010

Anion exchange membranes can be used for reverse electrodialysis for electric energy generation, and capacitive deionization for water purification, as well as electrodialysis for desalination. In this study, anion exchange membranes of poly((vinylbenzyl) trimethylammonium chloride-2-hydroxyethyl methacrylate)/poly(vinyl alcohol) were prepared through the polymerization of (vinylbenzyl)trimethylammonium chloride and 2-hydroxyethyl methacrylate in aqueous poly(vinyl alcohol) solutions, esterification with glutaric acid, and cross-linking reaction with glutaraldehyde. We investigated electrochemical properties for the anion exchange membranes prepared according to experimental conditions. Ion exchange capacity and electrical resistance for the membranes were changed with a variation in the monomer ratio in polymerization. Water uptake and conductivity for the membranes decreased with an increase in the content of glutaric acid in esterification. The change in the time of crosslinking reaction with the formed film and glutaraldehyde affected electrochemical properties such as water uptake, conductivity, or transport number for the membranes. Chronopotentiometry and limiting current density for the anion exchange membranes prepared were measured.

• Polymer(Korea)
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• v.30 no.3
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• pp.217-223
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• 2006

Ion exchange fibers, high functionalized onto hybrid polyolefine fiber's surface, were synthesized by $\gamma-ray$ mutual radiation. Degree of grafting (DG) of copolymer increased with increasing GMA monomer concentration and the maximum rate of DG was 355% at 50 GMA. The graft reaction occurred in polar solvent and DG was 190% maximum value in $1.0\times10^{-3}$ Mohr's salt and 0.1 M sulfuric acid, respectively. The amination for graft copolymers varied depending on amine reagents, and the reactivity for copolymers was highest for methylamine, and that of triethylamine lowest. It was shown that water uptake and ion exchange capacities increased with increase in the rate of amination while surface area decreased rapidly as proceeding for graft reaction and amination.

• Analytical Science and Technology
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• v.17 no.2
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• pp.91-97
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• 2004

Cryptand ion exchange resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene divinylbenzene (DVB) copolymer with crosslink of 1%, 2%, 5% and 10% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of uranium ($UO{_2}^{2+}$) ion were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ($UO{_2}^{2+}$), magnesium ($Mg^{2+}$), neodymium ($Nd^{3+}$) ion. The adsorption was in order of 1%, 2%, 5%, and 10% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.261-266
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• 2000

A kinetic study for nitrate removal by anion exchange resin was performed using continuous column reactors. Kinetic approach from the packed bed showed the reaction rate constant k$_1$ was 0.07~0.17 $\ell$/mgㆍhr and maximum exchange quantity q$_{o}$ was 27.75~31.81 mg/g. The results from the continuous column well agreed with that from the batch reactor. An economic analysis of the water treatment plant by anion exchange resin with a regenerating system was performed to design plant and process. Based on the treatment of 20 mg/$\ell$ nitrate-contained wastewater of 10,000 gallons per day to 2 mg/$\ell$, total capital cost and total annual cost are estimated to be 836 million wons and 211 million wons, respectively.y.

• Journal of Integrative Natural Science
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• v.6 no.3
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• pp.151-157
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• 2013

The ion exchange resins were synthesized from 1-aza-18-crown-6 macrocyclic ligand attached to styrene (2th petroleum in 4th class hazardous material) divinylbenzene (DVB) copolymer with crosslinks of 1%, 6%, and 15% by substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, surface area, and IR-spectrum. The object of this study was to seperate the metal ion absorbed in reinforcement water fire extinguishing agent. As the results of the effects of pH, equilibrium arrival time, and crosslink of synthetic resin on metal ion adsorption for resin adsorbent, the metal ions were showed high adsorption at pH 3 or over and adsorption equilibrium of metal ions was about 2 hours. In addition, adsorption selectivity for the resin in water was the order of Al (III) > Ni (II) > Sm (III) ions, adsorbability of the metal ions was in the crosslinks order of 1%, 6%, and 15%.

• Journal of environmental and Sanitary engineering
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• v.23 no.1
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• pp.57-65
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• 2008

Resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene(dangerous matter) divinylbenzene(DVB) copolymer with crosslink of 1, 2, 6 and 15% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time and crosslink on adsorption of metal ion　from water fire extinguishing agent by the synthetic resin adsorbent were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in water was in increasing order of $Mg^{2+}>Al^{3+}>Pb^{2+}$. The adsorption was in the order of 1, 2, 6, and 15% crosslink resin.

• Journal of Plant Biology
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• v.21 no.1_4
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• pp.33-38
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• 1978

Phosphate absorption from a Na2H32PO4 solution by Oryza sativa L. was studied in order to elucidate kinetic mechanisms of ion transport. The rates of phosphate absorption from different concentraitons indicated the presence of dual mechanisms in root tips, one in the low (1$\times$10-6 to 8$\times$10-5M) and the other in the high (1$\times$10-4 to 8$\times$10-3M). A phosphate compensation point of phosphate transport was revealed with a 1$\times$10-6M solution of Na2H32PO4. The kinetic model that ion transport involves an exchange reaction of absorption and desorptin is prosposed as follows: where C represents an ionic-specific organic carrier in the membrane; M, Mo and Mi are the mineral ions, M-outside and M-inside; MC is a carrier-ion complex; and the K's represent rate constants. In this model, the Mi velocity, v, is given by: {{{{v= {dMi} over {dt}= {(K1K3Mo-K2K4Mi) Ct} over {(K2＋K3)＋K1Mo＋K4Mi} }} where Ct is equal to C＋MC, and t is time.