• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.227-231
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• 2013

Electrodeionization is a hybrid separation process of electrodialysis and ion exchange to produce high purity water under electric field. This article provides a fabrication result of hole patterned metal electrode for elecrodeionization system. The hole patterns have been fabricated by nanosphere lithography (NSL). The technique utilizes the self-assembled nanospheres as lens-mask patterns and collimated laser beam source. The hole patterns have a periodic array structure. The images of hole pattern on metal electrode prepared were observed by SEM. We believe that the periodic hole patterned metal electrode structure is a useful device applicable for metal mat electrode in electrodeionization system.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.156.1-156
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• 2000

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.771-772
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• 2009

• Carbon letters
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• v.10 no.2
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• pp.114-122
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• 2009

Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.871-877
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• 2005

Recent progress in the filed of transition-metal mediated C-H bond activation has had a great influence on organic synthesis. Among such transition-metal catalyzed reactions, ortho-functionalization via the chelationassisted strategy has been paid great attentions as one of the powerful methodologies for converting aromatic compounds into ones that are more functionalized at the exclusively ortho-position. In this context, various transition metal-catalyzed ortho-functionalizations such as alkylation, alkenylation, silylation and carbonylation are described briefly and their prospects are suggested.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.487-498
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• 2006

The oxidation processes of metal catalysis were practically applied into the flexographic inks wastewater treatment to derive the most effective and economical system among all the processes of iron-salts coagulation, iron-catalyzed air oxidation, and coagulation followed by biological treatment. The iron concentration and pH were optimized as $2.8{\times}10^{-3}mol$ and 5.5~6.0, respectively, for all the oxidation processes. At the optimal reaction conditions, the removal efficiencies of $TCOD_{Mn}$ and Color were as follows for the respective process: i) 75% $TCOD_{Mn}$ and 77% Color removals for iron-salts coagulation, ii) 91% TCODMn and 90% Color removals for iron-catalyzed air oxidation, iii) 74~92% $TCOD_{Mn}$ and 81~90% Color removals for coagulation followed by biological treatment. Based on the economical and technological aspects, iron-catalyzed air oxidation was confirmed as the most effective process in the treatment of industrial wastewater.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.33-41
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• 2019

In this report, nano-sized catalysts were introduced onto fabric surface to eliminate toxic chemicals assisted by physical adsorption. For chemical removal of toxic compounds, a series of zirconium-containing catalysts were synthesized and treated on fabric to catalyze the hydrolysis and oxidation of target molecules. Antimicrobial was also introduced for the research purpose to prove the compatibility of as-synthesized catalysts with other solutions. Zirconium ligated with hydroxyl group and MOF(Metal-Organic Frameworks) were exploited as catalyst for removal of toxic compounds, while zinc complex was used for an antimicrobial to culminate in a chemical shield. Once fabrics were functionalized, fabrics were washed 2 or 5 times for a washing durability test. The amount of catalyst in textile were measured by ICP-MS and weight increasing ratio of fabrics.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.418-425
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• 2013

The catalytic conversion of ethanol to aromatic compounds ETA was studied over ZSM-5 heterogeneous catalysts. The effect of reaction temperature, weight hourly space velocity (WHSV), and addition of water and methanol, which are the potential impurities of bio-ethanol, on the catalytic performance was investigated in a fixed bed reactor. Commercial ZSM-5 catalysts having different Si/$Al_2$ ratios of 23 to 280 and modified ZSM-5 catalysts by addition of metal (Zn, La, Cu, and Ga) were used for the activity and stability tests in ETA reaction. The catalysts were characterized with ammonia temperature programmed desorption ($NH_3$-TPD) and nitrogen adsorption-desorption techniques. The results of catalytic performance revealed that the optimal Si/$Al_2$ ratio of ZSM-5 is about 50~80 and the selectivity to aromatic compounds decreases in the order of Zn/La > Zn > La > Cu > Ga for the modified ZSM-5 catalysts. Among these catalysts from the ETA reaction, Zn-La/ZSM-5 showed the best catalytic performance for the ETA reaction. The selectivity to aromatic compounds was 72% initially and 56% after 30 h over the catalysts at reaction temperature of $437^{\circ}C$ and WHSV of $0.8h^{-1}$.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.519-523
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• 2012

A kinetic study is reported on nucleophilic displacement reactions of benzyl 2-pyridyl carbonate 6 with alkalimetal ethoxides, EtOM (M = Li, Na, and K), in anhydrous ethanol at $25.0{\pm}0.1^{\circ}C$. The plots of pseudo-firstorder rate constant $k_{obsd}$ vs. [EtOM] curve upward, a typical phenomenon reported previously for alkaline ethanolysis of esters in which alkali-metal ions behave as a Lewis-acid catalyst. The kobsd value for the reaction of 6 with a fixed EtOK concentration decreases rapidly upon addition of 18-crown-6-ether (18C6), a complexing agent for $K^+$ ion up to [18C6]/[EtOK] = 1.0 and then remains constant thereafter, indicating that the catalytic effect exerted by K+ ion disappears in the presence of excess 18C6. The reactivity of EtOM towards 6 increases in the order $EtO^-$ < EtOLi < EtONa < EtOK, which is contrasting to the reactivity order reported for the corresponding reactions of 2-pyridyl benzoate 4, i.e., $EtO^-$ < EtOK < EtONa < EtOLi. Besides, 6 is 1.7 and 3.5 times more reactive than 4 towards dissociated $EtO^-$ and ion-paired EtOK, respectively. The reactivity difference and the contrasting metal-ion selectivity are discussed in terms of electronic effects and transition-state structures.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1506-1510
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• 2014

A kinetic study on nucleophilic substitution reaction of 5-nitro-8-quinolyl picolinate (6) with alkali-metal ethoxides (EtOM; M = K, Na, and Li) in anhydrous ethanol is reported. The plot of $k_{obsd}$ vs. [EtOM] curves upward in the absence of crown ethers but is linear with significantly decreased reactivity in the presence of crown ethers. Dissection of $k_{obsd}$ into $k_{EtO}$- and $k_{EtOM}$ (i.e., the second-order rate constants for the reactions with the dissociated $EtO^-$ and ion-paired EtOM, respectively) has revealed that the ion-paired EtOM is significantly more reactive than the dissociated $EtO^-$ (e.g., $k_{EtOM}/k_{EtO^-}$ = 33.4-141). This indicates that the reaction of 6 is catalyzed by $M^+$ ions in the order $Na^+$ > $Li^+$ > $K^+$ and the catalytic effect disappears in the presence of a proper crown ether. Picolinate ester 6 is much more reactive and is more strongly catalyzed by $M^+$ ions than 5-nitro-8-quinolyl benzoate (5). It has been concluded that $M^+$ ions catalyze the reaction of 6 by increasing electrophilicity of the reaction center through a cyclic transition state, which is structurally not possible for the reaction of 5.