• KSBB Journal
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• 제29권2호
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• pp.98-105
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• 2014

Three different types of extraction processes, which used supercritical carbon dioxide ($SCCO_2$) and organic solvent, were attempted to improve the extraction yield of oil from Chlorella vulgaris: cosolvent-modified $SCCO_2$ extraction, $SCCO_2$ extraction with ultrasonic sample treatment in organic solvent, and static extraction with organic solvent followed by dynamic $SCCO_2$ extraction. Among these, the last $SCCO_2$ extraction process was found to be most effective in the extraction of oil. Compared with pure $SCCO_2$ extraction, the extraction yield of oil was observed to increase about 7 times.

• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.283-292
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• 2023

Currently, spray coating has attracted interest in the mass production of anode catalyst layers for proton exchange membrane water electrolysis (PEMWE). The solvent in the spray ink is a critical factor for the catalyst dispersion in ink, the microstructure of the catalyst layer, and the PEMWE performance. Herein, various pure organic solvents were examined as a substitute for conventional isopropanol-deionized water (IPA-DIW) mixture for ink solvent. Among the polar solvents that exhibited better IrO₂ dispersion over nonpolar solvents, 2-butanol (2-BuOH) was selected as a suitable candidate. The PEMWE single cells were fabricated using 2-BuOH at various ionomer contents, spray nozzle types, and drying temperatures, and their performance was compared to the cells fabricated using a conventional IPA-DIW mixture. The PEMWE single cells with 2-BuOH solvent showed good performances comparable to the conventional IPA-DIW mixture case and highly durable performances under accelerated degradation tests.

• 한국산업융합학회 논문집
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• 제8권1호
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• pp.37-45
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• 2005

Adsorption equilibrium data of pure solvent vapors (n-Hexane, Toluene, MEK) as well as their binary mixtures on activated carbon (sorbonorit $B_4$) were experimentally determined in the range of 293.2~323.2 K and beyond saturated vapor pressure corresponding to experimental temperature. Langmuir, Freundlich, LRC, W-VSM, FH-VSM were estimated for the predication of single component as well as binary mixtuer systems. The isosteric heat of adsorption at infinite dilution of pure n-hexane, toluene, MEK on activated carbon were 45.18, 25.85, 34.62 Kcal/mol, respectively, also, n-hexane-toluene binary adsorption of activated carbon formed an azeotrope at 293.2 K and total pressure 5.1~10.3 mmHg.

• 생명과학회지
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• 제12권4호
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• pp.423-426
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• 2002

방향족 에폭사이드 기질에 대한 입체선택적 가수분해 활성이 우수한 Aspergillus niger LK를 이용하여 광학활성 (S)-para-nitrostyrene oxide를 제조하였다. 수용액에서 기질 의 낮은 용해도를 극복하기 위하여 유기용매에서 광학분할 반응을 수행하였으며, 생촉매 활성 저하가 가장 적은 dodecane을 유기용매로 선정하였다. 반응온도 3$0^{\circ}C$ 및 최적 water content 2% (v/v)의 조건에서 약 10시간 정도의 반응을 통해 ee 값이 100 %인 광학적으로 순수한 (S)-para-nitrostyrene oxide를 37% 정도(이론수율 : 50 %)의 높은 수율로 얻을 수 있었다.

• 한국전기전자재료학회논문지
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• 제18권7호
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• pp.641-646
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• 2005

To fabricate a single layer white organic light emitting diode (OLED), a novel non-conjugated blue emitting material PPPMA-co-DTPM copolymer was synthesized containing a perylene moiety unit with hole transporting and blue emitting ability and a triazine moiety unit with electron transporting ability. The devices were fabricated using PPPMA-co-DTPM $(PPPMA[70\;wt\%]:DTPM[30\;wt\%])$ copolymer by varying the doping concentrations of each red, green and blue fluorescent dye, by molecular-dispersing into Toluene solvent with spin coating method. In case of ITO/PPPMA-co-DTPM:TPB$(3\;mol\%):C6(0.04\;mol\%):NR(0.015\;mol\%)/Al$ structure, as they were molecular-dispersing into 30 mg/ml Toluene solvent, nearly-pure white light was obtained both (0.325, 0.339) in the CIE coordinates at 18 V and (0.335, 0.345) at 15 V. The turn-on voltage was 3 V, the light-emitting turn-on voltage was 4 V, and the maximum external quantum efficiency was $0.667\%$ at 24.5 V. Also, in case of using 40 mg/ml Toluene solvent, the CIE coordinate was (0.345, 0.342) at 20 V.

• Journal of Forest and Environmental Science
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• 제36권1호
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• pp.62-66
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• 2020

Ethanol fermentation of the enzymatic hydrolysates from the products pretreated using 1-ethyl-3-methyl-imidazolium acetate ([EMIM]Ac) and its co-solvents with dimethylformamide (DMF) was conducted using Saccharomyces cerevisiae (D452-2). The optical density change due to the yeast cell growth, the consumption amount of monosugars (glucose, xylose), the concentration of acetate, and ethanol production yield were investigated. The co-solvent system lowered inhibition of the growth of the cells. The highest concentration of glucose (7.8 g/L) and xylose (3.6 g/L) was obtained from the enzymatic hydrolysates of the pretreated product by pure [EMIM]Ac. The initial concentration of both monosugars in the enzymatic hydrolysates was decreased with increasing fermentation time. Ethanol of Approximately 3 g/L was produced from the enzymatic hydrolysates by pure [EMIM]Ac and co-solvent with less than 50% DMF.

• 멤브레인
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• 제31권5호
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• pp.363-370
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• 2021

본 연구에서는 유기용매에 저항성이 뛰어난 소재인 polyketone 고분자를 사용하여 열유도 상분리법(TIPS)으로 유기용매 저항성 중공사 분리막을 제조하였다. 희석제는 green solvent로 알려진 PEG300, DMSO₂, glycerine을 사용하였으며, 이때 사용된 diluent에 따라 나타나는 구정형 구조를 가지는 고-액 상분리와 bicontinuous한 구조를 가지는 액-액 상분리를 관찰하였다. 전반적인 분리막의 특성은 SEM, 수투과도, 기계적 강도, 내화학실험을 사용하여 고찰하였으며, 본 연구에서는 다양한 희석제가 적용된 polyketone 중공사 분리막의 제조와 그 상호관계에 대해 심도 있게 연구하였다.

• Journal of Electrochemical Science and Technology
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• 제6권1호
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• pp.16-25
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• 2015

Transition metal oxide nanocrystalline materials are playing major role in energy storage application in this scenario. Nickel oxide is one of the best antiferromagnetic materials which is used as electrodes in energy storage devices such as, fuel cells, batteries, electrochemical capacitors, etc. In this research work, nickel oxide nanoparticles were synthesized by combustion route in presence of organic fuels such as, glycine, glucose and and urea. The prepared nickel oxide nanoparticles were calcined at 600℃ for 3 h to get phase pure materials. The calcined nanoparticles were preliminarily characterized by XRD, particle size analysis, SEM and EDAX. To prepare nickel oxide electrode materials for application in supercapacitors, the calcined NiO nanoparticles were mixed with di-methyl-acetamide and few drops of nafion solution for 12 to 16 h. The above slurry was coated in the graphite sheet and dried at 50℃ for 2 to 4 h in a hot air oven to remove organic solvent. The dried sample was subjected to electrochemical studies, such as cyclic voltammetry, AC impedance analysis and chrono-coulometry studies in KOH electrolyte medium. From the above studies, it was found that nickel oxide nanoparticles prepared by combustion synthesis using glucose as a fuel exhibited resulted in low particle diameter (42.23 nm). All the nickel oxide electrodes have shown better good capacitance values suitable for electrochemical capacitor applications.

• 멤브레인
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• 제31권3호
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• pp.228-240
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• 2021

알코올성 용제를 재활용할 수 있는 목적의 유기용제나노여과막(OSN)을 내용제성이 우수한 폴리벤지다졸 고분자를 이용하여 비용매 유도 상분리법을 이용하여 제조하였다. 제조한 나노여과막의 모폴로지와 투과특성을 조절하기 위하여 도프 용액의 농도와 물과 에탄올의 혼합용액인 응고액의 조성을 변화시키면서 제조하였다. α,α'-dibromo-p-xylene (DBX)을 이용하여 가교한 폴리벤지미다졸 분리막은 유기용제나노여과막으로 사용하기에 충분한 기계적 강도와 내용제성을 갖는 것을 확인하였다. 물로만 이루어진 응고조에서 도프용액의 농도가 20%이상인 분리막을 제조하는 경우에 분자량 696.66 g/mol을 가지는 콩고레드에 대한 제거율은 90% 이상을 나타내었고, 투과도는 5 bar의 압력에서 22.5 LMH/bar를 나타내었다. 응고액 조성에 대한 연구를 통해서 응고액 중의 에탄올 농도가 증가할수록 에탄올의 투과도가 증가하는 것을 확인하였다.

• 폴리머
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• 제38권4호
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• pp.464-470
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• 2014

A chemo-mechanical method was used to prepare lignin-containing cellulose nanofibrils(L-CNF) from unbleached woodpulps dispersed uniformly in an organic solvent. L-CNF/PLA composites were obtained by solvent casting method. The effects of L-CNF concentration on the composite performances were characterized by tensile test machine, contact angle machine, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). The tensile test results indicated that the tensile strength and elongation-at-break increased by 50.6% and 31.8% compared with pure PLA. The contact angle of PLA composites decreased from $79.3^{\circ}$ to $68.9^{\circ}$. The FTIR analysis successfully showed that L-CNF had formed intermolecular hydrogen bonding with PLA matrix.