• Bulletin of the Korean Chemical Society
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• 제21권7호
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• pp.669-670
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• 2000

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.378-378
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• 2009

The ionic liquid-based sulfonated hydrocarbon composite membranes was prepared for use in anhydrous high temperature-polymer electrolyte fuel cells (HT-PEFCs). Ionic liquid behaves like water in the composite membranes under anhydrous condition. However the composite membranes show a low conductivity and high gas permeability as the content of ionic liquid increases due to its high viscosity and content of ionic liquid, respectively. Hence, in order to enhance the proton conductivity and to reduce the gas permeability of the composite membranes with low content of ionic liquids, the acid containing a common ion of ionic liquid was added to the composite membranes. The characterization of composite membranes was carried out using small-angle X-ray scattering (SAXS), thermogravimetric analyzer (TGA) and impedance spectroscopy. As a result, the composite membranes containing acid showed higher proton conductivity than those with no acid under the un-humidified condition due to a decrease in viscosity. In addition, the proton conductivity of composite membranes increased with increasing mole concentration of acid.

• 통합자연과학논문집
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• 제8권4호
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• pp.235-243
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• 2015

Rhodium(I)-complex of $[Rh(CO)_2I_2{^-}]$ catalyzed carbonylation of anhydrous-trimethylamine in the presence of methyl iodide to give DMAC (N,N-dimethylacetamide) in no solvent. The catalyst had been reused 20 times, the analyses and distillation of collected products showed that the yields of DMAC, MAA (N-methylacetamide), and DMF (N,N-dimethylformamide) were 82.3%, 12.6%, and 4.4%. The conversion rate of trimethylamine was 99 % and the selectivity of DMAC was 82.3% with TON (Turnover Number) of 700. Stepwise procedure of inner-sphere reductive elimination for the formation of DMAC was suggested instead of acyl iodide intermediate.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.515-516
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• 2010

• Korean Chemical Engineering Research
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• 제48권3호
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• pp.365-374
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• 2010

농산폐기물인 폐버섯배지의 목재 펠릿 연료화 가능성을 탐색하기 위하여 국내 발생량이 가장 많은 새송이버섯, 팽이버섯, 느타리버섯 폐배지를 대상으로 산(acid) 첨가 용매추출에 의한 회분감소 실험을 수행하였고 이에 따른 연료특성 변화를 탐색하였다. 새송이버섯 폐배지는 초산 2%(w/w), 무수구연산 1%(w/w) 첨가군, 액비 1:8, 추출온도 $55^{\circ}C$, 추출시간 180분의 추출조건에서 무처리군의 회분함유량 8.81%(w/w), 발열량 3,958.3 kcal/kg 대비 각각 3.33%(w/w), 4,219.2 kcal/kg로 성능을 극대화시킬 수 있었으며, 팽이버섯 폐배지는 초산 3%(w/w), 무수구연산 1%(w/w) 첨가군, 액비 1:8, 추출온도 $65^{\circ}C$, 추출시간 180분의 추출조건에서 무처리군의 회분함유량 14.91%(w/w), 발열량 4,190.3 kcal/kg 대비 각각 4.07%(w/w), 4,627.6 kcal/kg로 성능이 극대화되었으며, 느타리버섯 폐배지는 초산 1%(w/w), 무수구연산 1%(w/w) 첨가군, 액비 1:7, 추출온도 $65^{\circ}C$, 추출시간 180분의 추출조건에서 무처리군 대비 회분함유량이 3.31%(w/w)에서 0.59%(w/w)로 감소효과가 극대화되었고 발열량은 4,558.6 kcal/kg 대비 4,216.2 kcal/kg로 감소효과가 최소화됨으로써 성능이 극대화되었다.

• Journal of Pharmaceutical Investigation
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• 제23권2호
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• pp.81-87
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• 1993

Five crystalline forms of cimetidine, four anhydrous and a monohydrate, have been prepared, and their thermal behavriours have been studied by differential thermal analysis and thermo-gravimetry. The dissolution rates of the five forms were determined in distilled water at $37^{\circ}C$. The results showed a significant difference in the dissolution rate. Polymorphic transformation occurred spontaneously during storage at room condition and was accelerated by applied energy during formulation process-milling.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.1902-1906
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• 2011

Sulfonated poly(fluorinated arylene ether)s (SDF-F)/poly[(N-vinylimidazole)-co-(3-methacryloxypropyl-trimethoxysilane)] (poly(VI-co-MPS))/poly(tetrafluoroethylene) (PTFE) is prepared for a high temperature proton exchange membrane fuel cell (PEMFC). The reaction of the membrane with phosphoric acid forms silicate phosphor, as a chemically bound proton carrier, in the membrane. Thus-formed silicate phosphor, nitrogen in the imidazole ring, and physically bound phosphoric acid act as proton carriers in the membrane. The physico-chemical and electrochemical properties of the membrane are investigated by various analytical tools. The phosphoric acid uptake and proton conductivity of the SDF-F/poly(VI-co-MPS)/PTFE membrane are higher than those of SDF-F/PVI/PTFE. The power densities of cells with SDF-F/poly(VI-co-MPS)/PTFE membranes at 0.6 V are 286, 302, and 320 mW $cm^{-2}$ at 150, 170, and 190 $^{\circ}C$, respectively. Overall, the SDFF/poly(VI-co-MPS)/PTFE membrane is one of the candidates for anhydrous HT-PEMFCs with enhanced mechanical strength and improved cell performance.

• 약학회지
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• 제42권3호
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• pp.284-289
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• 1998

The effect of reaction condition, solvent addition and thermal treatment on the bulk density, crystallinity and chemical properties of the freeze-dried cefazohn sodium was inves tigated to prepare the cefazolin sodium powder for injection with good flowability. Crystalline cefazolin sodium powder with high untapped-bulk density (about 45%) and low compressibility (about 40%) was obtained by solvent addition to the very highly concentrated cefazohn sodium solution followed by subsequent thermal treatment before freeze-drying. The desirable solvent was low substituted alcohol such as isopropyl alcohol and anhydrous ethanol with the final concentration of about 9%. The pH adjustment and nitrogen gas purging during the reaction did not give significant effect on the chemical properties such as content, color, transmittance and pH of the reconstituted cefazolin sodium aqueous solution.

• Bulletin of the Korean Chemical Society
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• 제22권2호
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• pp.199-204
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• 2001

A Cryptate (221) having a short alcohol pendant (2) was metallated with europium(Ⅲ) in anhydrous condition, and its hydrolytic activity for phosphate esters at neutral pH was examined. While the activity for the phosphate diester and monoester is comparable to that of the parent metal complex [1Eu]3+, its hydrolytic activity towards a phosphate triester is significantly suppressed. Potentiometric titration and luminescence spectroscopic studies for the equilibrium behavior of the complex in solution suggest that a dimer formation through the metal hydroxides as well as the pendant alcohol is likely to happen. The low hydrolytic activity for the triester seems to be associated with the dimer formation.

• Journal of Pharmaceutical Investigation
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• 제5권3호
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• pp.50-57
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• 1975

Bismuthsubgallate is a compound of indefinite composition containing bismuth and gallic acid. Because its structure was indefinite, many papers have been reported for it. But these are different one another and the relationship between the physical properties, structure and manufacturing condition has not been yet reported. In this experiment, bismuthsubgallate was prepared from bismuthsubgallate and gallic acid in an acetic medium at $65^{\circ}$, and dried at four different temperatures $30^{\circ}\;65^{\circ}\;105^{\circ}\;and\;155^{\circ}$. And some of the other relative bismuth organic compounds were prepared. To each product. elemental analysis, IR spectra and DTA, TGA curves were determined. These results revealed the followings; l. The structure of bismuthsubgallate is comfirmed as a complex form of gallomonohydroxo-bismutic acid monohydrate and its yellow colour dependent upon complex anion in the structure. 2. According to the drying temperature, the hydrate content of bismuthsubgallate is quite different: dihydrate at room temperature, mono-hydrate at. $65^{\circ}$, anhydrous at $105^{\circ}$ and decomposed partial1y oganic substance of the structure above $155^{\circ}$.