• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.582-587
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• 2022

Biphasic solvents are attracting attention as energy-reducing solvents for capturing CO₂ from flue gas in combustion process. In this study, considering diethylenetriamine (DETA) and diethylethanolamine (DEEA) mixed solvents, one of the biphasic solvents by blending of two types of amines, the CO₂ absorption rates of DETA and DEEA was measured by wetted wall column. The effects of DETA and DEEA concentrations and operating temperature on the overall mass transfer coefficient were investigated. As a result, the overall mass transfer coefficient was proportional to the DETA concentration. However, in the case of the DEEA concentration, the effect was small and when the concentration was exceeded, the overall mass transfer coefficient decreased. The DETA aqueous solution showed little change in the overall mass transfer coefficient with the operating temperature, whereas the DEEA aqueous solution increased the overall mass transfer coefficient with the operating temperature. As a result of obtaining the observed reaction rate constant under the pseudo-first-order reaction assumption, it was found that the observed reaction rate constant in DETA aqueous solution was proportional to the DETA concentration, but DEEA did not fit the pseudo-first-order reaction assumption.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.825-827
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• 2012

In this study, the variation in surface morphology of copper phthalocyanine (CuPc) thin films treated with a flow of acetone vapor assisted by nitrogen carrier gas was investigated. The CuPc nanorods with similar dimensions were well dispersed throughout the whole film surfaces after ~20 min. of treatment. However, the electronic absorption spectra only changed slightly, which indicates that molecular stacking was not altered during treatment. This treating method is simple and more advantageous compared to other solvent treating technologies such as mixed solvent spray treatment using organic solvents and water since it requires relatively mild treating conditions and does not need the presence of water.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.45-51
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• 1987

Methyl orange(MO) and cetyltrimethylammonium bromide(CTA) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 419nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the CTA-MO calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of CTA concentration of $1.5\times$$10^{-5}$~1.0$\times$$10^{-4}M$ by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparations.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.120-126
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• 1999

This study was accomplished by measuring the lower and upper flash point with air blowing method and grasping the characteristics of flammability for the three component systems, which are made up of the Benzene-Toluene-o-Xylene and Methylethylketone-Toluene-o-Xylene. These three component systems are widely used in the various industrial fields together with the development of industry. The results are as follows ; 1 ) Isothermal line is plotted on the triangular diagram for flash points determined in each solutions. From this line, the mixed compositions which indicated the same lower and upper flash points in each different composition could be read on this diagram, if the composition of mixtures are known. 2) Lower and upper explosion limits obtained from the flash points determined for the three component solution are compared with the value calculated from Le Chatelier's law. Especially the lower explosion limits are in a good agreement with the calculated values.

• YAKHAK HOEJI
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• v.19 no.1
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• pp.30-35
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• 1975

pKi values and sensitivity of acid-base indicators in the mixed solvent systems of water-alcohols and water-acetone at differential pH and in concentration media were determined by spectrophotometric method. When the concentration of the organic solvents were increased, the pKi values of sulfophthalein indicators, thymol blue and bromcresol purple, became larger whereas those of an axo indicator, methyl yellow, became smaller nad the pH values of the equivalent points of acids became smaller and the pH values of the equivalent points of acids became higher than those in the aqueous solution. potassium bicarbonate, a standard compound used in the organic solvent systems without a prerequisite procedure of expelling carbon dioxide by boiling.

• YAKHAK HOEJI
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• v.23 no.3_4
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• pp.133-140
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• 1979

The adsorption of erythrosine in the aliphatic alcohols by antibiotics such as ampicillin anhydrous, ampicillin trihydrate, amoxicillin trihydrate, cephalexin monohydrate was studied. The adsorption isotherms were all described with Freudlich equation. From the various experimerts, it was found that the adsorption of erythrosine by antibiotics in the aliphatic alcohols was affected by the solubility of adsorbents. The adsoption in the mixture of aliphatic alcohols and water is related with the dielectric constant of mixed solvents. According to increase in the pH values of aqueous solution, the adsorption of erythrosine for antibiotics is decreased, but increased in the mixture of aliphatic alcohols and water. The adsorption of erythrosine in the suspension of antibiotics showed a correlation with the temperature. Colloidal silica which is used as stabilizer had a favorable effect on the adsorption of erythrosine in the suspension of antibiotics.

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.155-163
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• 1993

This study was conducted to investigate the optimal condition of the extraction of red pepper oleoresin. The yield of oleoresin form red pepper was 24~28% when it was extracted by ethanol and methanol. and 8~10% by acetone, ethylene dichloride and n-hexane. But more than 60% of portion in alcohol extracts were moisture and sugars. Capsaicin and pigment were extracted more than 70% of those in red pepper when it was extracted by ethylene dichloride Those useful components were extracted most efficiently by mixed solvents of ethanol and ethylene dichloride at the ratio of 50:150. other extracting conditions were investigated in this studies, such as optimal extraction time was more than 3 hours, temperature was 55$^{\circ}C$ and particle size was finer than 250 mesh

• YAKHAK HOEJI
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• v.35 no.1
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• pp.15-21
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• 1991

Quaternary amines which are widely used as medicines are nitrogen compounds. Metanil yellow(MY) and benzalkonium chloride(BKC) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 402 nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the BKC-MY calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of BKC concentration of 2$\times$$10^{-6}$~9$\times$$10^{-6}$M by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.2
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• pp.96-101
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• 2009

The purpose of this study was to conduct the field validation of alternative method(ETM method) by using non-carcinogenic, and less toxic solvents than NIOSH (National Institute for Occupational Safety and Health) analytical method 5524 for measuring the airborne metalworking fluids in workplaces. We carried out the field validation test by using the exposure chamber, guaranteeing the air sampling homogeneously in a machining environment. The ETM mixed solvent presented the complete solubility of MWFs used in test field. Based on the field test data, the bias of the ETM method from reference method, NIOSH analytical method 5524, was from -7.0% to 5.1%. The overall uncertainty of the ETM nethod was 21.6%, which satisfied the NIOSH criteria for the sampling and analytical criteria.

• Bulletin of the Korean Chemical Society
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• v.16 no.1
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• pp.17-21
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• 1995

A new series of polyarylate copolyesters were prepared by melt polycondensation of 1,4-diacetoxy-2,5-(α-phenylisopropyl)benzene with mixture of terephthalic acid and isophthalic acid in varying ratio. And their general properties such as the glass transition temperature, crystalline melting temperature, crystallinity and solubility were studied. The intrinsic viscosity values of the present polymers measured in a mixed solvent of phenol/p-chlorophenol/1,1,2,2-tetrachloroethane ranged from 0.45 to 0.66 depending on the composition and molecular weight. The copolyesters containing greater than 20 mole % of isophthalic acid were found to be amorphous, whereas the homopolymer derived from terephthalic acid was semicrystalline with a melting point of 414℃. The glass transition temperatures of the polymers ranged from 165 to 180℃ depending on the composition. The copolyesters containing 50 mole % and greater of isophthalic acid moiety were soluble at room temperature in such common solvents as tetrahydrofuran, chloroform and N,N-dimethylformamide.