• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.296-300
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• 2003

A large equilibrium and kinetic data set for multi-component cation exchanges was obtained and tested with mass action law and surface complexation model. The systematic batch equilibrium and column experiments of cation adsorption were conducted for binary, ternary, quaternary, and quinary cation exchanges involving $ H^{+}, Li^ {+}, Na^{+}, NH$_4$^{+}, Mg^{2+} $ on a strongly acidic cation exchange resin IRN 77. The mass action law and surface complexation model were tested against both data set to investigate the consistency of ion selectivity and their predictability for competitive cation exchanges. Surface complexation model provided more accurate predictions for both equilibrium and kinetic experimental data than mass action model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.307-311
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• 2003

The test did for the determine the optimized ratio of cation to anion in mixed ion exchange demineralizers. Binary, ternary, quaternary, and quinary cation and anion adsorption was performed to develop a comprehensive experimental data set from small-volume batch tests to obtain the selectivity coefficients of many cations and anions. The quantitative run time might be estimated by such ion exchange models as semi-empirical mass action and surface complexation models. The demineralizer can be used longer by increasing the ratios of cation to anion exchange resins in the bed.

• Journal of the Korean Chemical Society
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• v.28 no.1
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• pp.62-69
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• 1984

The reaction of toluene with ethanol was studied over various cation-exchanged pentasil zeolite catalysts. The toluene disproportionation reaction to produce xylenes increased with increasing reaction temperature and the activity of alkylation of toluene with ethanol showed maximum at around $400^{\circ}C$. Only Cs-ZSM-5 catalyst showed pronounced p-ethyltoluene selectivity increasing to 96% with increasing degree of Cs-exchange. The sorption rate of m-xylene was lower for Cs-exchanged ZSM-5 than H-ZSM-5 catalyst. These phenomena were interpreted in terms of shape selectivity arising from the partial blocking of channel intersections by large cesium ions.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.67-75
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• 1997

Heterogeneous cation exchange membrane consisting of cation exchange resin particles (diameter of less than $149{\mu}$) which are finely dispersed in a polyethylene matrix, were produced as forms of sheet. The characteristics were measured after treating hot water or saturated sodium chloride. When membranes were treated with hot water or saturated sodium chloride, cation exchange resin particles swell and expand pushing away the polyethylene matrix of membranes. The above treatment results the formation of narrow cavities between a cation exchange resin particles and polyethylene matrix, and the formation of fine micro-cracks on the polyethylene matrix. Thus, we were obtained good physical and electrochemical properties. On the treatment with hot water or saturated sodium chloride, the optimum conditions for good heterogeneous cation exchange membrane were treatment time of 30min and treatment temperature of $90^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.163-167
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• 2012

Since D-xylose is not fermentable in Saccharomyces cerevisiae, its conversion to D-xylulose is required for its application in biotechnological industries using S. cerevisiae. In order to convert D-xylose to D-xylulose by way of an enzyme immobilized system, D-xylose isomerase (XI) of Escherichia coli was fused with 10-arginine tag (R10) at its C-terminus for the simple purification and immobilization process using a cation exchanger. The fusion protein XIR10 was overexpressed in recombinant E. coli and purified to a high purity by a single step of cation exchange chromatography. The purified XIR10 was immobilized to a cation exchanger via the electrostatic interaction with the C-terminal 10-arginine tag. Both the free and immobilized XIR10 exhibited similar XI activities at various pH values and temperatures, indicating that the immobilization to the cation exchanger has a small effect on the enzymatic function of XIR10. Under optimized conditions for the immobilized XIR10, D-xylose was isomerized to D-xylulose with a conversion yield of 25%. Therefore, the results of this study clearly demonstrate that the electrostatic immobilization of XIR10 via the interaction between the 10-arginine tag and a cation exchanger is an applicable form of the conversion of D-xylose to D-xylulose.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.137-146
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• 1992

The adsorption properties of CO on the cation exchanged natural zeolite, $K_{111}$ and cation effects upon the CO adsorption were studied. $Na^+-,\;Cu^{2+}-\;and\;Ba^{2+}-\;K_{111}$ exhibited relatively good CO adsorption capacities and $Ba^{2+}- K_{111}$ treated by 0.4 N-$BaCl_2$ solution proved itself as the best adsorbent and superior to the synthetic zeolite 4A and 5A. The observed adsorption tendency due to the cations were in the order of $Ba^{2+}>Cu^{2+}>Na^+>K^+>Mg^{2+}>Ca^{2+}$. The cation exchanged number per unit cell as well as the kind of cation which forms bond with CO molecules in different intensities and other mineral factors such as pore size indicated to be important factors to the CO adsorption properties. The CNDO/2 calculations were performed to compare the adsorption tendencies and CO interaction energy of cations in $K_{111}$.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.248-248
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• 2003

층상이중수화물(Layered Double Hydroxides, LDH)은 층 사이에 무기물 음이온이 있는 2차원 충상구조물로서 이들 층 사이의 공간에 이동 가능한 수화된 음이온의 존재로 전하균형을 이룬다. 층 사이의 음이온은 교환이 가능하며, 나머지의 공간은 물분자로 채워져 있다. 이러한 특성을 응용하여 LDH는 촉매, 음이온 교환제, 흡착제, 담체로 사용가능하며, 특히 음이온 교환능이 있는 소재로 고분자에 적용되고 있으며, 층간에 염료를 삽입한 복합체의 제조 둥에 관한 연구가 활발히 이루어지고 있다. 이의 적용에서 LDH의 입도는 결정적인 한계 요인으로 작용하기도 한다. 본 실험에서는 Mg-Al-NO$_3$ 층상이중수산화물(Mg-Al-NO$_3$-LDH)을 공침전법으로 합성하고, 양이온의 농도와 공침시 pH 및 교반조건의 변화가 생성된 LDH의 결정상, 형상, 입도, 및 양이온교환능에 미치는 영향을 알아보았다. 특히 초음파 분산법을 적용하는 경우 생성되는 LDH 입자크기의 미세화에 효과적인 것을 확인 할 수 있었다.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.98-105
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• 2014

Lysozyme amounts to 0.3% in egg white and functions as an agent of cell lysis and activator of tissue reconstruction. Ion exchange chromatography is the most useful method of separation among affinity chromatography, ion exchange chromatography, and ultra-filtration. The aim of present study is to find the optimum pH and temperature for the separation of lysozyme in egg white within cation exchange gel filled glass column. And we compared results of experiments with those of simulations. Phosphate buffer was used, and pH and temperature were varied as 5~7 and $25{\sim}40^{\circ}C$ respectively. RP-HPLC was the tool for the retention time identification and quantitative analysis of lysozyme. OriginPro 8 measured the peak area of lysozyme chromatogram and quantified the eluted lysozyme. Largest amount of lysozyme was separated under the conditions of pH 5 and T $25^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.9 no.2
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• pp.584-590
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• 1982

Copolymerization of the 4-vinylpyridine with vinylacetate and divinylbenzene initiated by azobis-isobutyronitrile was carried out in DMF in presence $BaCl_2$ at $98^{\circ}C$. Ion exchange res in, poly 4-vinylpyridine-vinylsulfonic acid-divinylbenzene was prepared by sulfonation of 4-vinylpyridine-vinylacetatp-divinylbenzene with concentrated sulfuric acid. The compositions of each synthetic resin were identified by means of ir adsorption spectroscopy. Anion and cation capacities of 4-vinylpyridine-vinylsulfonic acid-divinylbenzene ion exchanger were 2.5meq/g and 4.8meq/g, respectively. Adsorption of Cd(II) and Cu(II) ions have showed larger quantity in alkalie media. A study also was made of the influence of alcohol on the distribution coefficient of Cd(II) and Cu(II) ions between the synthetic ion exchanger, and solution containing hydrochloric acid, various alcohols and water. The distribution coefficients of metal ions decrease generally as the number of branches of carbon in the molecule of butyl alcohol increase. (t-BuOH

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.181-188
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• 2013

The effect of transition metal ion exchange into UZM-9 zeolite with LTA framework on its deactivation in methanol-to-olefin (MTO) conversion was discussed. The ion exchange of copper, cobalt, nickel, and iron did not induce any notable change in the crystallinity, crystal morphology, and acidity of UZM-9. The small cage entrance of UZM-9 caused the high selectivity to lower olefins in the MTO conversion, while its large cages allowed the rapid further cyclecondensation of active intermediates, polymethylbenzenes including hexamethylbenzene, resulting in a rapid deactivation. The UZM-9 containing copper and cobalt ions showed considerably slow deactivations. The interaction between transition metal ions and polymethylbenzene cation radicals, the active intermediates, generated in the MTO conversion stabilized the radicals and slowed down the deactivation of UZM-9.