• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.313-318
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• 2020

Bi₂WO₆ were successfully synthesized using EGME, GL, EG and water as solvents by a conventional hydrothermal method. They were characterized by XRD, DRS, BET and SEM and we also investigated the photocatalytic activity of these materials for the decomposition of Rhodamin B under visible light irradiation. The XRD results revealed the successful synthesis well-crystallized Bi₂WO₆ crystals with Aurivillius structure when EGME and EG are used as solvents. In addition, the well-crystallized Bi₂WO₆ crystals showed the flower-like structure. The Bi₂WO₆ catalysts prepared at 180 ℃ using EGME as a solvent showed the highest photocatalytic activity. The Bi₂WO₆ catalysts prepared at mole ratio of H₂O/EGME more than 50% showed high photocatalytic activity.

• 한국유가공학회:학술대회논문집
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• 2001.05a
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• pp.15-23
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• 2001

It is very interest to use transparent milk for various determination because milk emulsion or colloidal state bring out opacity. The fat globule can disperse by butanone and casein complex can also disintergrate to monomer by action of Triton with aide of SDS and NaOH in same milk phase at time because it can be possible that butanone have amphiphilic characteristic solvent also miscible. Our formulution of solvent can treat almost all type of milk products except with proportion of Triton/Butanone such as 8:2 and 9:1 . In spite of growth inhibition to contact with solvent it call be use also for microbial counting because this formulution did not attactk wall. This is why present technique can be applied to diver determination for the reason of milk payment system, quality control, and national planning or control of national dairy.

• Korean Chemical Engineering Research
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• v.44 no.2
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• pp.121-128
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• 2006

Propylene epoxidation by $H_2O_2$ (30％ aqueous) as oxidant was studied in a semi-batch reactor using TS-1 catalyst: Effects of reaction temperature, time, pressure, solvent, catalyst and $H_2O_2$ concentration on $H_2O_2$ conversion (limiting reagent) and product distribution were investigated. Potential inhibition by propylene oxide on the epoxidation rate was also examined. Ti-MCM-22 with MWW zeolytic structure was found to exhibit better performance than TS-1 with MFI structure, provide that a proper choice of solvent(acetonitrile) is made.

• Polymer(Korea)
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• v.29 no.5
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• pp.493-500
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• 2005

Polyhydroxyamides(PHAs) having poly(ethylene glycol)methyl ether (MPEG) and/or dimethylphenoxy pendant groups were synthesized by solution polycondensation at low temperature. The inherent viscosities of the PHAs measured at $35^{\circ}C$ in DMAC or DMAc/LiCl solution were in the range of $0.51\~2.31dL/g$. This precursor polymers were studied by FT-IR, $1H-NMR$, DSC, and TGA. Solubility of the precursors with higher MPEG unit was increased, especially the polymer having MPEG $(M_n=1100)$ was soluble or partially soluble in ethanol, methanol, and water as well as aprotic solvents, but the PBOs were nearly insoluble in a variety of solvents. PHAs were converted to polybenzoxazoles (PBOs) by thermal cyclization reaction with heat of endotherm. In case of the precursors having MPEG nit, the precursor polymers with a higher $M_n$ were fully cyclized at a lower temperature than one with a lower $M_n$.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.160-160
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• 2011

I-III-VI족 화합물 반도체인 $CuInS_2$(CIS) 박막은 Cu(In,Ga)$Se_2$에 비해서 독성원소를 사용하지 않으므로 환경 친화적이고 Ga, Se를 사용하지 않아 조성의 조절이 쉬우며 태양전지의 이상적인 밴드갭인 1.5 eV에 근접한 1.53 eV의 직접천이형 에너지 밴드갭을 가지고 있어 태양전지의 광흡수층으로써 유망한 재료이다. CIS 박막 증착에는 다양한 방법이 있으며 본 연구에서는 chamber를 진공으로 만들고 CIS를 구성하는 용액으로부터 미립자화 된 입자를 노즐을 통하여 팽창시켜 에어로졸을 생성하고 입자들의 운동에너지를 증착에 직접 이용 할 수 있는 Aerosol Jet Deposition (AJD)라는 방법을 이용하려고 한다. 이 방법은 높은 증착속도로 우수한 박막을 성장시킬 수 있는 저비용 및 단순공정으로 CIS를 증착 할 수 있는 새로운 방법이다. 물을 용매로 하여 수용액 상태의 $CuCl_2{\cdot}2H_2O$, $InCl_3$, $(NH_2)_2CS$를 혼합하여 CIS 용액을 제조하고 carrier gas를 주입하여 CIS 용액을 노즐로 이동시켜 팽창시킨다. 용액이 팽창되면서 온도가 감소하여 응축이 일어나며 이 응축된 용액이 가열된 기판 위에 충돌하여 용매가 증발하면서 결정화된 CIS가 증착이 된다. CIS의 특성은 용액의 전구체 비율, 기판 온도, 팽창 전 압력, chamber 압력 등의 영향을 받는데 본 연구에서는 기판 온도를 증착변수로 선택하여 CIS 박막을 증착하고 박막의 특성을 고찰하고자 한다.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.239-246
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• 1990

Monascus anka strains with higher pigment production were developed using UV mutation and natural selection. To obtain organic solvent soluble pigments from Monascus anka, the following culture conditions were compared : standing and shaking culture with Nishikawa's medium, and shaking culture with Lin's medium. Shaking culture in Lin's medium exhibited decrease in solvent-soluble intracellular pigments after initial increase. The decrease was accompanied by the increase in water-soluble extracellular pigments. Monascus anka preferred sucrose and ethanol among 7 carbon sources tested. Treatment of sterol biosynthesis inhibitors, $({\pm})$-miconazole and chlorocholine chloride(CCC) , directed carbon pool to the biosynthetic pathway leading to the pigments with CCC's more pronounced effect. Two dimensional TLC revealed at least 7 yellow pigments suggesting existence of hereto unreported pigment. One of the most abundant yellow pigments was isolated and found to be ankaflavin by NMR and MS analysis.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.779-785
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• 1994

The interaction between the cationic dye, thionin(Th) and the anionic surfactant, sodium dodecyl sulfate (SDS) has been investigated by absorption spectra. As the temperature of surfactant solution was increased in premicellar range(S/D=10, 80, and 160) which was much lower than the critical micelle concentration(CMC), the increment or decrement of the molar extinction coeffecient ratio appeared. It was found that the most stable temperature range of the oligomer aggregate in Th-SDS system at S/D=160 was below $60^{\circ}C$. With increasing the concentration of inorganic salt and organic solvents in Th-SDS system, ${\alpha}$-band was increased, but ${\gamma}$=band or J-band was decreased. The orders of ${\alpha}$-band increasing power were $Cl^-$>$ClO{_4}{^-}$>$SO{_4}{^{2-}}$>$NO{_3}{^-}$ and 2-propanol>ethanol>methanol>ethylene glycol.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.42-49
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• 2000

A new method for the quantitative determination of capsaicinoids in microcapsule has been developed. Among seventeen solvents tested for solubilizing wall material (gum arabic and modified starch) of microcapsule, dimethyl sulfoxide (DMSO) was selected as an optimal solvent. The most appropriate mixing ratio of microcapsule to DMSO for solubilizing wall material was 1 to 10(w/v). Appropriate carriersolubilizing temperature and time were $55^{\circ}C$ and 30 min, respectively. Also conditions for extracting oleoresin from the solubilized microcapsule were studied. The mixing ratio of ethanol to DMSO was optimal at 8 to 1(v/v). Optimized vortexing time was 5 min at 40㎐. Pecipitant was obtained by centrifugation at 21000 rpm for 15 min. The precipitant was reextracted with ethanol. The extracted supernatants were combined and adjusted to final volume of 25 ml. Extracted solutions were analyzed for quantitation of total capsaicinoids by employing HPLC and for quantitation of total carotenoids by spectrophotometric method. This method can be used to monitor changes of capsacinoid during manufacturing or storage of red pepper oleoresin microcapsule powder.

• Journal of the Korean Electrochemical Society
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• v.12 no.3
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• pp.203-218
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• 2009

The development of lithium-ion battery (LIB) technologies and their application in the field of large-scale power sources, such as electric vehicles (EVs), hybrid EVs, and plug-in EVs require enhanced reliability and superior safety. The main components of LIBs should withstand to the inevitable heating of batteries during high current flow. Carbonate solvents that contribute to the dissociation of lithium salts are volatile and potentially combustible and can lead to the thermal runaway of batteries at any abuse conditions. Recently, an interest in nonflammable materials is greatly growing as a means for improving battery safety. In this review paper, novel approaches are described for designing highly safe electrolytes in detail. Non-flammability of liquid electrolytes and battery safety can be achieved by replacing flammable organic solvents with thermally resistive materials such as flame-retardants, fluorinated organic solvents, and ionic liquids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.350-356
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• 2011

Styela plicata of large (9.82~11.66 g) and small (0.93~2.21 g) sizes harvested at different times was extracted with 4 different solvents (methanol, ethanol, acetone, and water). DPPH radical scavenging and reducing power was the highest in acetone extracts of small ones (38.98% and 1.724, respectively) harvested in November. The lowest radical scavenging activity was found in water extracts of large ones (12.03% and 0.114) in December. On the other hand, large ones harvested in September showed significantly higher inhibition rate of DNA damage (water, 56.54%; methanol, 55.83%; ethanol, 48.63%) than others. Overall, the water extraction of S. plicata tended to show a higher antigenotoxic effect. In addition, water extracts of large S. plicata from November showed the highest angiotensin converting enzyme (ACE) inhibitory activity (64.38%), while that of small ones from December exhibited the lowest (51.33%). Overall the results indicate that antioxidant and antihypertensive activities S. plicata are variable depending on harvesting time, size, and extraction solvent.