• 대한화학회지
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• 제65권5호
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• pp.309-312
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• 2021

The solvolysis of (1s)-(+)-menthyl chloroformate (1) were studied kinetically in 28 pure and various mixed solvents. The analysis using the extended Grunwald-Winstein equation in the solvolysis of 1 obtained the l value of 2.46 ± 0.18, the m value of 0.91 ± 0.07, and the correlation coefficient of 0.950. The solvolysis of 1 might proceed via an associative S_N2 mechanism enhancing bond making than bond breaking in the transition state (TS). The value of l/m is 2.7 within the ranges of value found in associative S_N2 reaction. This interpretation is further supported by a relatively large solvent kinetic isotope effect (SKIE, 2.16).

• 한국염색가공학회지
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• 제6권3호
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• pp.37-43
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• 1994

Commercial Poly(ethylene terephthalate) (PET) filaments were treated in solvents mixtures such as benzyl alcohol/perchloroethylene(BA/PER), benzyl alcohol/trichloroethylene(BA/TRI), benzyl alcohol/ethylene chloride(BA/EC), metha nol/perchloroethylene(ME/PER), and methanol/trichloroethyle(ME/TRI). Swelling of PET in solvent mixtures showed rapidly in the middle range of mixture ratio. Contribution of swelling of each component to total swelling of binary mixtures with increasing treated time was generally showed in proportion to the mixture ratio of the each component in dependence of the extend of swelling.

• Bulletin of the Korean Chemical Society
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• 제7권6호
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• pp.416-421
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• 1986

The solvent coordination effect on the excited state processes of Mg(II)- and Zn(II)-phthalocyanines has been described. The triplet state of these compounds decays with mixed first and second order kinetics or mainly second order kinetics depending on the solvents used. The first order component of the rate constants decrease along with the series, dimethylsulfoxide (5-coordinated), 1-chloronaphthalene (4-coordinated) and piperidine (6-coordinated), while the second order rate constant is dependent on the diffusion rate constant of the solvents. The excited state quenching by methylviologen or p-benzoquinone is discussed. And ion recombination rate constant is given.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.292.1-292
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• 1999

• 한국초등과학교육학회지:초등과학교육
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• 제20권1호
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• pp.139-147
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• 2001

This paper is to study on the change of volume and temperature of the solution which mixed water with ethanol. And its main purpose is to examine closely how the volume changes, and to find the method to maximize the change of the volume. The summaries for results of the study are; First, we were known that water and ethanol are homogeneously mixed. But two solvents does not mix homogeneously by different specific gravity at early stages. Second, we could see that the volume changed large at homogeneous mixed water with ethanol by stirrer, the change of volume is the largest value when water mixed with ethanol in the ratio of one to one. Third, when water mixed with ethanol in the ratio of one to one, the change of temperature is very large by activated hydrogen bond. We conclude that it is the best result when ratio of water and ethanol is one to one and the solution is well mixed.

• 한국의류학회지
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• 제22권3호
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• pp.265-265
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• 1998

The phase behavior of chlorinated hydrocarbon/mixed surfactants/water microemulsion systems were investigated for dry cleaning solvent properties. With appropriate surfactant mixtures, Winsor type I-III-II microemulsions were generated which is the same as hydrocarbon systems. For perchloroethylene(PCE) with mixed Tween systems, the optimum salinity(S*) decreases and the optimum solubilization parameter(o*) increases with decreas- ing HLB. For PCE with mixed Aerosol MA and ethoxylated alcohol systems, S* and o* both increase with increasing ethylene oxide moles. For dichlorobenzene(DCB) with mixed Aerosol MA and ethoxylated or propoxylated sulfate systems, S* and o* both increase with increasing ethylene oxide moles or propylene oxide moles.

• 한국의류학회지
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• 제22권3호
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• pp.365-373
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• 1998

The phase behavior of chlorinated hydrocarbon/mixed surfactants/water microemulsion systems were investigated for dry cleaning solvent properties. With appropriate surfactant mixtures, Winsor type I-III-II microemulsions were generated which is the same as hydrocarbon systems. For perchloroethylene(PCE) with mixed Tween systems, the optimum salinity(S*) decreases and the optimum solubilization parameter(o*) increases with decreas- ing HLB. For PCE with mixed Aerosol MA and ethoxylated alcohol systems, S* and o* both increase with increasing ethylene oxide moles. For dichlorobenzene(DCB) with mixed Aerosol MA and ethoxylated or propoxylated sulfate systems, S* and o* both increase with increasing ethylene oxide moles or propylene oxide moles.

• 대한화학회지
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• 제17권3호
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• pp.207-212
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• 1973

毛細灌法을 利用하여 여러가지 混合溶媒系(dioxane-n-butanol, dioxane-sec-butanol, dioxane-ethyleneglycol, dioxane-kerosene)중에서 polyvinylacetate의 희박용액을 機械的으로 切斷하여 그 결과로 얻어진 平均切斷速度定數(k) 및 極限重合度(g)를 moleculare dimension이 동일한 조건하에서 比較검토하였다. 그 결과 k보다는 g의 값이 사용하는 solvent의 종류에 따라 크게 영향을 받음을 알았으며 이에 關하여 考察하였다.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2003년도 연료전지심포지움 2003논문집
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• pp.189-192
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• 2003

In this work, we have prepared platinum catalyst by various methods, investigated fuel cell performance and compared performance with commercially available $20\%$ Pt supported on carbon (Pt/C) catalyst. We have found that Pt/C prepared by reduction of chloroplatinic acid in mixed solvent (water+ethylene glycol) gives better performance compared to that produced by reduction of aqueous chloroplatinic acid, which can be attributed to smaller catalyst particle size and lower agglomeration in the mixed solvent. We have also prepared a novel platinum electrocatalyst by depositing platinum on Nafion coated carbon powder and it shows great promise. The performance of electrode prepared using $20\%Pt$ onn Nafion coated carbon mixed with Pt/C was found to be higher than the performance of electrodes using commercially available $20\%$ Pt/C, up to a current density of about $1100mA/cm^2$. The cell voltages obtained were respectively 621 and 603mV, at a current density of: $1000mA/cm^2$, in a single cell using $0.25mgPt/cm^2$ and Nafion 10035 membrane at $80^{\circ}C$ using hydrogen/oxygen reactants at 1 atm pressure.

• 한국응용과학기술학회지
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• 제14권3호
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• pp.29-38
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• 1997

Low toxic concentrated oil dispersant using n-Paraffin and Di(ethylene glycol)mono butylether mixed solvent was prepared, and tested by oil dispersant performance test method, and oil dispersant efficiency was measured using vertical shaking method to 3 kinds of Crude oil, Bunker oil and W/O emulsions with different physical properties by appling the prepared dispersant. Although toxicity test was performed with Flat fish and Rock fish by appling the mixed oils emulsified using prepared oil dispersant, couldn't find the toxicity to them. Concentrated oil dispersant prepared has a good dispersion efficiency of 97.2% after 0.5min settling time and 28.3% after 10min settling time to Bunker B oil with 10% water solution. Especially, the concentrated oil dispersant showing the low toxicity to Oryzias Latipes(24hr, TLm) was 54,000 ppm and to Brine Shrimp Artemia(24hr, TLm) was 51,000ppm, and also, it was completely biodegradated to 99.1% after $7{\sim}8$days.