• Membrane and Water Treatment
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• 제6권5호
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• pp.411-422
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• 2015

Membrane modification by different concentrations of acrylic acid has been described. Grafting of acrylic acid to the surface of a polypropylene membrane was obtained by a Fenton-type reaction. Membrane permeability seemed to have been dependent on the value of pH in the solution. To explain tendency, a simple theoretical model was developed. The model incorporates explicitly statistical conformations of a polyacid chain grafted onto the pore surface. The charged capillary model with a varying diameter for porous membranes was then used to evaluate the permeability of the membrane. It has been shown both theoretically and experimentally that the permeability of a grafted membrane depends on the pH of the solution.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 가을 학술발표회 발표논문집
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• pp.319-321
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• 2003

This research was carried out to evaluate the removal efficiencies of CODcr and colour for the dyeing wastewater by ferrous solution in Fenton process. The results showed that COD was mainly removed by Fenton coagulation, where the ferric ions are formed in the initial step of Fenton reaction. On the other hand colour was removed by Fenton oxidation rather than Fenton coagulation. The removal mechanism of CODcr and colour was mainly coagulation by ferrous ion, ferric ion and Fenton oxidation. The removal efficiencies were dependent on the ferric ion amount at the beginning of the reaction. However the final removal efficiency of COD and colour was in the order of Fenton oxidation, ferric ion coagulation and ferrous ion coagulation. The reason of the highest removal efficiency by Fenton oxidation can be explained by the chain reactions with ferrous solution, ferric ion and hydrogen peroxide.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.71-72
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• 2012

The purpose of this study is not only fixation of carbon dioxide using the cement-Paste solution's calcium ion by wet carbonating reaction but also quantitatively evaluate the possibility of storage technology of Carbon dioxide. wet carbonation is reaction of CO₂ injection by CO₂ reactor. As a result of experiment, the carbon dioxide is fixed, and high-purity Calcium Carbonate is eluted.

• 분석과학
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• 제8권4호
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• pp.655-661
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• 1995

The electrochemical reduction of coumarin derivatives in 0.1M TEAP acetonitrile solution was investigated by the direct current, differential pulse polarography, cyclic voltammetry and controlled potential coulometry. The electrochemical reduction of 7-acetoxy-4-bromomethyl-coumarin(ABMC) was proceeded as an irreversible three steps(-0.58, -1.63 and -2.25 volts) of electrochemical transfer before chemical reaction. The solution color turned to yellow after the carboxyl group was reduced at 2nd step(-1.63 volts vs. Ag-AgCl) and the change in color was independant to the bromo group. Upon the basis of the results on the products analysis and the interpretaton of polarograms, a possible electrochemical reaction mechanism was suggested.

• 한국세라믹학회지
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• 제34권10호
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• pp.1009-1014
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• 1997

Ammonia gas was blown into the solution of zirconium ion to induce precipitation of supersaturated zirconium ion at gas-liquid interface with increase in pH. The influence of pH on the phase and particle size of precipitate and calcined powders has been investigated. At pH 4.5 of zirconium solution, maximum yield of 98.7% was obtained. Above pH 4.5, there was no more increase of yield. Above pH 5.5, large aggregates consisting of primary particles were observed in precipitate and calcined powders. At pH 4.5, almost aggregate-free fine spherical zirconia powders were obtained.

• Bulletin of the Korean Chemical Society
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• 제23권7호
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• pp.990-994
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• 2002

Hydroxybenzothiophenes, dihydroxy-benzothiophenes, and benzothiophenedione were identified as inter-mediates of benzothiophene (BT) exposed to ultrasonic irradiation. It is proposed that benzothiophene is oxidized by OH radical to sequentially for m hydroxybenzothiophenes, dihydroxybenzothiophenes, and benzothiophenedione. Benzothiophene is decomposed rapidly following pseudo-first-order kinetics in a first-order manner by ultrasonic irradiation in aqueous solution. The toxicity of sonochemically treated solutions was checked by E. coli and a less inhibition in bacterial respiration was observed from the 120-min treated benzothiophene sample than from the untreated benzothiophene sample. Also evolution of carbon dioxide and sulfite was observed during ultrasonic reaction. A pathway for ultrasonic decomposition of benzothiophene in aqueous solution is proposed.

• Bulletin of the Korean Chemical Society
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• 제29권7호
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• pp.1332-1334
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• 2008

Stable crystalline 1-Benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane tribromide (BABOT), can be readily synthesized from the reaction of the corresponding bromide with $HNO_3$ and aqueous KBr. Selective Oxidation of a variety of dialkyl and alkyl Aryl sulfides to the corresponding sulfoxides in high yield was achieved by this reagent in solution ($CH_3CN/H_2O$) and solvent free conditions. The reaction proceeds under neutral and mild conditions and can be carried out easily at room temperature with regeneration of BABOT. In this method purification of products is straightforward and no over oxidation to sulfone was noted.

• 한국응용과학기술학회지
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• 제12권1호
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• pp.109-114
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• 1995

The Synthesis of long chain fatty acid containing azobenzene and $(C_{n}-Azo)$ was optimized, starting from p-(p'-hydroxy phenyl azo)-benzoic acid and the product of reaction containing azobenzene chromophores was investigated by ultraviolet spectrophotometery in chloroform solvent at the various temperature. In addition, Reversibility and stability of azo compounds have been measured by means of Ultraviolet and the structure of these compound were ascertained by means of FT-IR and NMR. Recrystallization of reaction product in the solvent results the experimental yield obtained about 62.93% p-(p'-octadecyloxy phenyl azo)-benzoic acid. Long chain azobenzene derivatives in chloroform solution are induced photoisomerization by u. v. and visible light irradiation. The solution of long chain fatty acids$(C_{n}-Azo)$ containing azobenzene are possible of being applied to functional molecular devices such as photomemory and light switching.

• 한국세라믹학회지
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• 제35권6호
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• pp.529-534
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• 1998

Agglomeration-free indium oxide particles were produced by ultrasonic pyrolysis of indium nitrate(3 hy-drate) solution. Th mean size of particles was increased from 3 $\mu\textrm{m}$ to 11$\mu\textrm{m}$ with increasing intial con-centrations of indium nitrate from 0.05mol% to 4.83 mol% When the input rate of indium nitrate solution was increased from 0.1 cm3/min to 0.8cm3/min the size of particles remained same and only the pro-duction rate of particles was increased. At 300$^{\circ}C$ the particles were white color with low crystallinity. But the color turned into yellow with increasing reaction temperature. The change of particle size was not ob-served with increasing temperatuer up to 700$^{\circ}C$ IR spectrum and TGA analysis confirmed that the purity of indium oxide was increased with temperature of reaction.

• 대한화학회지
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• 제55권4호
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• pp.575-580
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• 2011

Borate 완충용액에서 전극의 회전속도와 용액에 녹아 있는 $O_2$가 Zn-RDE의 부식에 미치는 영향을 조사하였다. 아연의 부식은 RDE의 회전속도와 산소의 양에 크게 영향을 받았으며, 부식 반응구조로 가역적 1-전자 전이에 이어서 일어나는 불균등화 반응(disproportion reaction)을 제안하였다.