• 한국대기환경학회지
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• 제8권1호
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• pp.58-67
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• 1992

For removing $NO_x$ and $SO_x$ from the flue gases emitted from stationary sources, $V_2O_5-MoO_3/TiO_2$ catalysts were prepared by the conventional impregnation method (aqueous solution) and a sort of surface fixation method(nonaqueous solution) as reported excellent reproducibility catalysts. And these catalysts observed their catalytic activities as well as their surface properties. V-Mo-O oxide, prepared from nonaqueous solution of $VOCl_3$ and $Mo(CO)_6$ and aqeous solution method, was supported as amorphous state by XRD and SEM measurements. The infrared spectra of fresh and used catalysts showed that in used catalysts, V=O bands decreased and new bands of vanadium oxysulfate bands were very sensitive. So the catalysts prepared from nonaqueous solution may bring about the high activity. Results from catalytic activity measurements at 350$^\circ$C, in the presence of $SO_2, NO$ conversion was more increased than in absence of $SO_2$. As the $MoO_3$ was added to $V_2O_5/TiO_2 system, SO_2$ conversion increased. It found that from the results, $V_2O-5-MoO_3/TiO_2$ catalysts prepared from an nonaqueous solution may bring about the high activity for both the reaction of NO and $SO_2$ removal.

• 대한화학회지
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• 제9권4호
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• pp.185-189
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• 1965

韓國産 酸性白土類 및 silica gel을 aniline yellow, o-nitro aniline, oil orange 色素 benzene 溶液과 작용시켜 非水溶液에서의 色素吸着率을 측정하였다. 그 吸着率은 silica gel이 酸性白土類보다 컸으며 酸性度에는 무관하였다. 또 上記 色素溶液에 각 10%의 添加溶劑 amine, alcohol, halogen類 化合物등을 加하여 高體酸의 色素吸着率의 변화(吸着阻害率)에 대하여 조사한 결과 위에 적은 順으로 그 영향이 적어지고, 同族體에서는 分子量이 적을 수록 그 영향이 커짐을 알았다. 따라서 非水溶液에서의 吸着은 amine基, 水酸基등과 같은 陰性基를 갖는 化合物은 選擇吸着하고 界面張力에 무관계하여 Traulbe系列의 逆轉現象을 나타내었다. 그 逆轉現象(吸着潮害現象)은 그 順位가 添加溶制의 雙極子能率과 대체적으로 일치하는 것으로 보아 固體酸模體인 活性硅酸과 被吸着體사이의 極盛的化學吸着에 의한 것이라 推定된다. 本實驗結果로부터 固體酸의 非水溶液에서의 吸着메카니즘, Traube 系列의 逆轉現象에 관하여 考察하게 되었다.

• 대한화학회지
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• 제24권3호
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• pp.209-217
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• 1980

요소 1,3-디메틸요소(DMU), 아세트아미드, 프로피온아미드의 상대점도와 삼투계수를 dimethylsulfoxide(DMSO), 메탄올, 에탄올 및 물용액에서 $25^{\circ}$C와 $45^{\circ}$C에서 각각 측정하였다. 수용액에서 각 용질의 점도증가량은 분몰랄부피가 증가하면서 증가하였으나 물아니 용액에서는 오히려 감소하였다. 또한 요소의 점도 증가량은 수용액에서는 DMU보다 작았으나, 물아닌 용액에서는 DMU보다 컸다. 그러나 아미드류는 어느 용매에서나 거의 같은 점도증가량을 나타내었다. 요소수용액에서 삼투계수는 DMU 수용액보다 컸으며, 물아닌 용액에서 요소용액은 DMU보다 Raoult의 법칙에서 크게 벗어났다. 이러한 사실로부터 요소는 DMSO 용액에서 자체회합을 크게 일으키고 있으며 알코올용액에서는 DMU보다는 큰 정도의 용매-용질상호작용, 수용액에서는 용매구조를 파괴하고 있음을 알았다. 아세트아미드나 프로피온아미드는 수용액이나 DMSO 용액에서보다 알코올용액에서 더 크게 용매구조를 파괴하고 있음을 알았다.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.212-217
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• 1998

The electrochemistry and valence tautomerism of CoⅢ(N-N)(SQ)(Cat), [N-N=N,N,N',N'-tetramethylethylenediamine (TMEDA); SQ=3,5- or 3,6-di-tert-butyl-semiquinone, Cat=3,5- or 3,6-di-tert-butyl-catechol], have been investigated by spectroscopic, electrochemical, spectroelectrochemical methods in nonaqueous solvents under anaerobic condition. The transition temperature between tautomers is dependent upon the donation effect of substituted quinone ligand and solvent. It increases with the increase of donation effect of solvent and quinone ligand. CoⅢ(TMEDA)(SQ)(Cat) is reduced to [CoⅡ(TMEDA)(SQ)(Cat)]-, and then reduces to [CoⅡ(TMEDA)(Cat)2]2-. CoⅢ(TMEDA)(SQ)(Cat) is oxidized to [CoⅢ(TMEDA)(SQ)2]+, but the stability of the oxidized form in DMF is dependent upon the solution temperature. With the increase of solution temperatrue the oxidized form may be converted to [CoⅡ(TMEDA)(SQ)(BQ)]+ by intramolecular electron transfer from SQ ligand to CoⅢ.

• 분석과학
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• 제7권3호
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• pp.361-369
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• 1994

가벼운 란탄족 이온($La^{3+}$, $Pr^{3+}$, $Nd^{3+}$, $Sm^{3+}$ 및 $Eu^{3+}$)의 전기화학적 거동을 acetonitrile(An), N, N-dimethylformamide(DMF)에서 직류 및 펄스차이 폴라로그래피와 순환 전압-전류법으로 연구하였다. $La^{3+}$, $Pr^{3+}$ 및 $Nd^{3+}$은 0.1M TEAP 지지 전해질에서 3전자 비가역반응으로 금속으로까지 환원되었으며, $Sm^{3+}$과 $Eu^{3+}$는 2단계 환원으로 진행되었다. 순환 전압-전류법의 결과에서 $Sm^{3+}$과 $Eu^{3+}$의 첫 단계 환원반응은 유사가역적 반응이었으며, 두 번째 단계의 환원은 비가역반응이었다. 펄스차이 폴라로그래피의 환원봉우리전류는 주사속도가 느리고 농도가 짙을수록 흡착특성을 크게 나타냈다. AN 용매에서 물의 부피가 증가할수록 가벼운 란탄족 이온의 환원전위는 음전위 방향으로 이동하였으며 환원전류는 감소하였다. DMF 용매에서는 물의 부피비가 증가할수록 양전위 방향으로 이동하였으며 환원전류는 감소하였다.

• 한국결정학회지
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• 제14권2호
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• pp.67-72
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• 2003

Graphite powders were coated with ZrO₂ by the controlled hydrolysis of a DI water, ethanol and DI water+ethanol solutions. The hydrolysis process was carried out with temperature control because of the low wettability of Zr ions to the surface of the graphite. PVA was added to the solution for the enhancement of metal ion adsorption. The surface of the graphite powders coated with ZrO₂ was observed by SEM and TEM. There are two types of ZrO₂ particles with the condition of ZrOCl₂°§8H₂O aqueous solutions were used; (a) primary particles a few nm in size and (b) secondary particles with ∼0.1 ㎛ size were obtained. The graphite powders coated in 50% ethanol-50% DI water solution of Zr(SO₄)₂ㆍ4H₂O have the relatively uniform coating layer and the starting temperature of oxidation was 100℃ higher than the raw graphite.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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• pp.1049-1055
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• 1999

Electrochemical oxidation of silicon (p-type Si(100)) at room temperature in ethylene glycol and in aqueous solutions has been performed by applying constant low current densities for the preparation of thin SiO2 layers. In-situ ac impedance spectroscopic methods have been employed to characterize the interfaces of electrolyte/oxide/semiconductor and to estimate the thickness of the oxide layer. The thicknesses of SiO2 layers calculated from the capacitive impedance were in the range of 25-100Å depending on the experimental conditions. The anodic polarization resistance parallel with the oxide layer capacitance increased continuously to a very large value in ethylene glycol solution. However, it decreased above 4 V in aqueous solutions, where oxygen evolved through the oxidation of water. Interstitially dissolved oxygen molecules in SiO2 layer at above the oxygen evolution potential were expected to facilitate the formation of SiO2 at the interfaces. Thin SiO2 films grew efficiently at a controlled rate during the application of low anodization currents in aqueous solutions.

• Bulletin of the Korean Chemical Society
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• 제18권5호
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• pp.496-500
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• 1997

Electrochemical behavior of mer-tris(2-pyridinethiolato)cobalt(Ⅲ) in dimethylformamide was studied on a platinum electrode by means of cyclic voltammetry, chronoamperometry, and chronocoulometry. It was found that the neutral complex molecule was electroactive between the potential region of 1.0 and - 1.2 V vs. a nonaqueous Ag/Ag+ electrode. The Co(Ⅲ) complex was reversibly reduced to Co(Ⅱ) species by one-electron transfer at about - 1.1 V, followed by an irreversible dissociation reaction. However, the oxidation process at around 0.8 V, was responsible for an irreversible two-electron transfer that occurred at a ligand site.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1498-1501
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• 1996

To evaluate insulating properties of polyimide thin film on high temperature over $100\;^{\circ}C$, polyimide film were prepared by electrophoretic deposition onto metal surface from nonaqueous emulsion. The emulsion is made by adding a solution of the resin to a precipitant, which is an organic liquid compeltely miscible with the solvent of the organic resin solution, but which does not dissolve the resin. The polyimide film obtained by annealing shows good insulation properties of 5.8 MV/cm at elevated temperature and breakdown strength of the film reveals thickness dependence.

• 대한화학회지
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• 제65권2호
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• pp.125-132
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• 2021

An electrochromic nickel oxide thin film was fabricated on a flexible PET/ITO substrate using a nanocrystallite- dispersed coating sol and bar coater. Nanocrystalline NiOx of 3-4 nm crystallite size was first synthesized by base precipitation and thermal conversion. This NiOx nanocrystallite powder was mechanically dispersed in an alcoholic solvent mixed with a silane binder to prepare a coating sol for thin film. This sol method is different from the normal sol-gel method in that it does not require the conversion of precursor by heat treatment. Therefore, this method provides a very facile method to prepare NiOx thin films on any kind of substrate and it can be easily applied to mass production. The electrochromic performance of this NiOx thin film on PET/ITO electrode with a thickness of about 400 nm was investigated in a nonaqueous LiClO4 electrolyte solution by cyclic voltammetric and repeated chronoamperometric measurements in conjunction with spectrophotometry. The visible light modulation of 44% and the colorization efficiency of 41 ㎠/C at 550 nm were obtained at the step potentials of -0.8/+1.2 V vs Ag and a duration of 30 s.