• Journal of the Korean Chemical Society
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• v.25 no.1
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• pp.26-29
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• 1981

Reactions of m-xylene were studied in a fixed-bed type micropulse reactor over cation-exchanged dealuminated mordenite and zeolite Y catalysts. Over H-mordenite catalysts higher catalyst pretreatment temperature as well as dealumination resulted in the increase of the formation of disproportionation product. $Ba^{2+}- and Mg^{2+}-$exchanged mordenite catalysts showed the shape selectivity in the disproportionation reaction of m-xylene, that is, the formation of trimethylbenzene decreasing sharply as the degree of cation exchange increased.

• Journal of the Korean Electrochemical Society
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• v.18 no.1
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• pp.24-30
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• 2015

To desalinate the aqueous solutions with high salt concentration using the capacitive deionization technology, two resin/membrane capacitive deionization(RMCDI) cells were fabricated by filling mixed ion exchange resins in two different flow channels (spacer and spiral type). The salt removal efficiency of the spacer- and spiral-RMCDI was 77.21 and 99.94%, respectively. Many ions were significantly removed in a spiral RMCDI cell because the feed solution could be more evenly contacted with the ion exchange resins filled on the spiral type flow channel. As the result of the changes of pH and accumulative charges, it was observed that Faradaic reaction was diminished for a spiral RMCDI cell filled by the mixture of cation and anion exchange resins. Therefore, the desalination of the aqueous solutions with high salt concentration by the capacitive deionization technology was proven. In addition, further studies on the optimization of the mixing ratio with ion exchange resins and the introduction of the regeneration process generally occurred in the continuous electrodeionization (CEDI) technology are required to improve the RMCDI technology.

• The Journal of Engineering Research
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• v.4 no.1
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• pp.109-118
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• 2002

In this research, the cation-exchange-reactions between Na-Montmorillonite and betaine compound, $R_{11}SO_4$, with acid group at the end of alkyl chain were performed under the general condition with dist. water including $CO_2$ and under the different pH-conditions with dist. water without $CO_2$, and their behaviors were observed. As results the exchange reaction under the general condition was perfectly finished after 49 h exchange time, and the basal spacings obtained under the exchange solution and after washing with methanol and drying in high vacuum were 23.6, 17.1 and $15.0\AA$, respectively. The basal spacings obtained under pH-exchange solution after exchange time under different pH-values lied between about 24.7 and $25.6\AA$ independently of the pH-values, and those measured after drying on the air and in high vacuum were about $20.0\AA$ and $13.8~14.4\AA$, respectively.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.249-254
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• 1998

To synthesize cation exchange resin which has thermal stability, the sulfonated poly(ether ether sulfone) (SPEES) was obtained by sulfonation after synthesis of poly(ether ether sulfone) (PEES). It was prepared from hydroquinone and dichlorophenyl sulfone. From FT-IR results, the sulfonation was confirmed by the bands of asymmetric O=S=O stretching of $SO_3Na$ Na group at $1140cm^{-1}$ and S-C stretching at $621cm^{-1}$. The optimum condition of the sulfonation of PEES, based on IR absorbance, was 3 hr of reaction time, $30^{\circ}C$ of reaction temperature, and chlorosulfonic acid of 150 mol%. Ion exchange capacities calculated by the IR absorbance of PEES sulfonated in optimum condition was 6.2 meq/g, which was nearly similar to the ion exchange capacity calculated by titration. When the metal ion was adsorved, small brain, lump, hulled millet shape and compact surface, were observed in the morphology of SPEES.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.5
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• pp.204-210
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• 2004

Though the recycling rate of coal fly ash generated from domestic thermoelectric power plants is gradually increased, at present, the most amount of coal bottom ash is disposed by a landfill instead of recycling. Therefore, to reuse a coal bottom ash as high-value materials the synthesis of zeolite made from a coal bottom ash was investigated in this study. NaPl, hydroxy-sodalite and tobermorite were produced through the alkaline hydrothermal reaction of pulvelized bottom ash at various temperatures; 80, 120, $150^{\circ}C$, and the concentration of NaOH at the range from 1 to 5 M. Especially, NaPl with excellent cation exchange capability had a high crystallinity at ${\leq}2$ M NaOH and ${\leq}120^{\circ}C$.

• 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.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1007-1011
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• 2011

Dioctyl succinates and succinic anhydride were synthesized from succinic acid in the presence of a cation exchange resin, Amberlite IR-120. The synthesis of dioctyl succinate from succinic acid and octanol was perfomed in 18 h reflux condition with Amberlite IR-120 and the isolated yield of product was over 90%. For the synthesis of succinic anhydride, succinic acid was refluxed in isopropenyl acetate for 18 h with Amberlite IR-120 as a catalyst. The long reaction time was significantly reduced to less than 10 min under microwave irradiation. The catalyst was reusable at least 4 times with keeping product yield of higher than 80%.

• Resources Recycling
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• v.11 no.3
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• pp.3-9
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• 2002

Relnoval of ammonia from aqueous solutions has been studied with zeolite and bentonite minerals. Zeolite and bentonite powder were supplied by a domestic company and used as delivered without further purification. The aqueous pH was found to increase by addition of zeolite or bentonite up to pH 8.5 from initial pH of 5.5∼5.7. From the C.E.C. measurement by ammonium acetate leaching method, the values of C.E.C. of zeolite and bentonite sample were observed to be 129.7 meq/100 gr and 65.1 meq/100 gr, respectively and Na+ ion accounted for the major part of total C.E.C. in both cases. In the removal of ammonia with zeolite and bentonite, physical adsorption of ammonium ion onto minerals was believed to contribute to the removal of it as well as the intrinsic cation exchange reaction. Finally, zeolite was found to be superior to bentonite in the removal of ammonia from aqueous solutions.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.421-430
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• 2014

In this study, a series of autoclave experiments were conducted in order to investigate the geochemical and mineralogical effects of carbon dioxide on deep subsurface environments. High pressure and temperature conditions of $50^{\circ}C$ and 100 bar, which are representative environments for geological $CO_2$ sequestration, were created in stainless-steel autoclaves for simulating the interactions in the $scCO_2$-groundwater-mineral reaction system. Zeolite, a widespread mineral in Pohang Basin where many researches have been focused as a candidate for geological $CO_2$ sequestration, and groundwater sampled from an 800 m depth aquifer were applied in the experiments. Geochemical and mineralogical alterations after 30 days of $scCO_2$-groundwater-zeolite sample reactions were quantitatively examined by XRD, XRF, and ICP-OES investigations. The results suggested that dissolution of zeolite sample was enhanced under the acidic condition induced by dissolution of $scCO_2$. As the cation concentrations released from zeolite sample increase, $H^+$ in groundwater was consumed and pH increases up to 10.35 after 10 days of reaction. While cation concentrations showed increasing trends in groundwater due to dissolution of the zeolite sample, Si concentrations decreased due to precipitation of amorphous silicate, and Ca concentrations decreased due to cation exchange and re-precipitation of calcite. Through the reaction experiments, it was observed that introduction of $CO_2$ could make alterations in dissolution characteristics of minerals, chemical compositions and properties of groundwater, and mineral compositions of aquifer materials. Results also showed that geochemical reactions such as cation exchange or dissolution/precipitation of minerals could play an important role to affect physical and chemical characteristics of geologic formations and groundwater.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.731-736
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• 2010

In this study, the sulfonated SBS cation-exchange membrane was prepared by post-sulfonation. Degree of sulfonation(DS), water-uptake, ion exchange capacity and electrical resistance and conductivity of sulfonated SBS were investigated as a function of sulfonation time. The DS of sulfonated SBS membrane was increased with increasing the reaction time and concentration of sulfuric acid. The maximum value of DS was 24.0%. And also, the water uptake and ion exchange capacity of the sulfonated SBS membrane were increased as increasing the value of DS. The values of water uptake and IEC were 41.2% and 0.80 meq/g, respectively. The electrical resistance and conductivity of the membrane showed $23.6{\Omega}{\cdot}cm^2$ and $4.24{\times}10^{-4}S/cm$, respectively.