• Title/Summary/Keyword: 용매 분해

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Characteristics of Asphaltene Structure and its Decomposition by Chemical Treatments (Asphaltene의 구조특성과 화학적 처리에 의한 분해특성)

  • 이창환;윤병대;정덕영;이효진
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.57-61
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    • 2001
  • 일반적으로 Asphaltene은 원유뿐만 아니라 화석연로원(Fessil Fuel Sources)에도 포함되어 있는 것으로 알려져 있으며 난분해성으로 탄화수소(Hydrocarbon)와 Heterocyclic 또는 N-, S-, 산소를 포함하는 화합물이다. 그리고 금속성 물질이 Asphaltene Fraction에 농축되어 있는 것으로 알려져 있다. 한편 이러한 metallo-complex는 Asphaltene의 구조화합물중 방향족계 sheet 사이에 Self-association 상태로 존재한다. Asphaltene의 분해는 일반 TPH나 BTEX계 유류의 분해 기작과는 매우 상이하며 현재까지 Asphaltene으로 오염된 토양의 복원 기술을 매우 미미한 것으로 알려져 있다. 따라서 본 연구는 Asphalteme으로 오염된 토양의 복원 기숙을 개발하기 위한 전단계로 Asphaletene의 구성물질과 저분자화 작용기작을 구명하여 효과적 복원기술 개발을 위하여 Arabian Light Oil에서 Oil 자체와 Oil에서 분리해낸 Asphaltene을 사용하여 용매조건과 처리제별로 저분자화 과정을 조사하였다.

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The novel methods for doping of Ru oxide on TiO2 nanotubes thin-film on Ti substrate by electrochemical anodization (타이타늄 나노튜브 박막 상의 루테늄 산화물의 전기화학적 도핑 방법)

  • Yu, Hyeon-Seok;O, Gi-Seok;Choe, Jin-Seop
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.235-236
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    • 2015
  • $TiO_2$는 표면적이 넓고 안정성이 높아 자체의 높은 밴드갭(3.0~3.2 eV)에도 불구하고 산업적으로 염소분해 전극으로써 사용되며, 최근 물분해 전극 적용 연구가 진행되고 있다. 전기화학적 물분해 반응을 위해서는 높은 과전압이 요구되므로 산업적으로 이용하기 위해 전도성을 향상시키기 위한 연구가 필요하다. 이러한 문제를 해결하기 위해 촉매제의 도핑이 연구되고 있으며 본 연구에서는 표면에 촉매를 도핑시키기 위한 두가지 방법을 연구하였다. 일반적으로 촉매로 사용되는 금속은 루테늄과 이리듐 등의 귀금속이며 촉매가 균일하게 도핑이 될수록 성능은 향상된다. 본 연구에서는 루테늄을 촉매로 선택하였으며 서로 다른 도핑 방법과 용매 하에서 물분해 실험을 진행하여 두 가지 방법의 물분해 효율을 비교하였다.

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Study of fabrication of anodic TiO2 nanotube and transition metal catalyst doping on its surface (양극산화 타이타늄 나노튜브 제작 및 전이금속 촉매 표면처리에 대한 연구)

  • O, Gi-Seok;Yu, Hyeon-Seok;Choe, Jin-Seop
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.336-337
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    • 2015
  • $TiO_2$는 표면적이 넓고 안정성이 높아 자체의 높은 밴드갭(3.0~3.2 eV)에도 불구하고 산업적으로 염소분해 전극으로써 사용되며, 최근 물분해 전극 적용 연구가 진행되고 있다. 전기화학적 물분해 반응을 위해서는 높은 과전압이 요구되므로 산업적으로 이용하기 위해 전도성을 향상시키기 위한 연구가 필요하다. 이러한 문제를 해결하기 위해 촉매제의 도핑이 연구되고 있으며 본 연구에서는 표면에 촉매를 도핑시키기 위한 두가지 방법을 연구하였다. 일반적으로 촉매로 사용되는 금속은 루테늄과 이리듐 등의 귀금속이며 촉매가 균일하게 도핑이 될수록 성능은 향상된다. 본 연구에서는 루테늄을 촉매로 선택하였으며 서로 다른 도핑 방법과 용매 하에서 물분해 실험을 진행하여 두 가지 방법의 물분해 효율을 비교하였다.

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Antioxidative Effects of Solvent Extracts of Lycii fructus Powder (LFP) and Maejakgwa Made with LFP (구기자 용매추출물과 구기자 매작과의 항산화 효과)

  • Park, Bock-Hee;Cho, Hee-Sook;Kim, Dong-Han
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.9
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    • pp.1314-1319
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    • 2005
  • The purpose of this study was to investigate the antioxidative effects of Lycii fructus powder (LFP) solvent extracts and Maejakgwa made with LFP. The solvent extracts of LFP were added to soybean oil in the quantity of $0.05\%$. The solvents used were methanol, ethanol, ethyl acetate and petroleum ether. Soybean oil without the addition of LFP was used as a negative control. Soybean oil with $0.02\%$ butylated hydroxytolune (BHT) and $\alpha$-tocopherol were used as positive controls. Each sample was stored at $50^{\circ}C$ for 30 days. The oxidation level of these samples was determined by measuring the acid value, peroxide value and thiobarbituric acid (TBA) value. The oxidation level of solvent extracts of $0.05\%$ LFP was lower than both the negative control and $\alpha$-tocopherol. Especially, methanol extract of $0.05\%$ LFP was the lowest. The methanol extract (320 min) and ethanol extract (316 min) demonstrated longer induction periods, compared to the control (253 min), $\alpha$- tocopherol (255 min) and BHT (309 min) by Rancimat method. Acid value of Maejakgwa was increased during the storage time, but it was lower in Maejakgwa made with LFP than in the control group. Peroxide value was increased rapidly for 30 days and then decreased. TBA value was lower in Maejakgwa made with 3, 6, $9\%$ LFP than in those made with $15\%$ LFP and the control.

Solvent-tolerant Lipases and Their Potential Uses (유기용매 내성 리파아제와 그 이용가능성)

  • Joo, Woo Hong
    • Journal of Life Science
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    • v.27 no.11
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    • pp.1381-1392
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    • 2017
  • This review described solvent-tolerant lipases and their potential industrial, biotechnological and environmental impacts. Although organic solvent-tolerant lipase was first reported in organic solvent-tolerant bacterium, many organic solvent-tolerant lipases are in not only solvent-tolerant bacteria but also solvent-intolerant bacterial and fungal strains, such as the well-known Bacillus, Pseudomonas, Streptomyces and Aspergillus strains. As these lipases are not easily inactivated in organic solvents, there is no need to immobilize them in order to prevent an enzyme inactivation by solvents. Therefore, the solvent-tolerant lipases have the potential to be used in many biotechnological and biotransformation processes. With the solvent-tolerant lipases, a large number insoluble substrates become soluble, various chemical reactions that are initially impossible in water systems become practical, synthesis reactions (instead of hydrolysis) are possible, side reactions caused by water are suppressed, and the possibility of chemoselective, regioselective and enantioselective transformations in solvent and non-aqueous systems is increased. Furthermore, the recovery and reuse of enzymes is possible without immobilization, and the stabilities of the lipases improve in solvent and non-aqueous systems. Therefore, lipases with organic-solvent tolerances have attracted much attention in regards to applying them as biocatalysts to biotransformation processes using solvent and non-aqueous systems.

Nucleophilic Substitution at a Carbonyl Carbon Atom (IX). Solvolysis of 2-Furoyl Chloride and 2-Thenoyl Chloride in Binary Mixtures (카르보닐탄소원자의 친핵성 치환반응 (제9보). 이성분 혼합용매에서 2-염화테노일 및 2-염화퓨로일의 가용매분해반응)

  • Son Jin-Eon;Sang-Kee Yoon;Ikchoon Lee
    • Journal of the Korean Chemical Society
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    • v.23 no.6
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    • pp.339-348
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    • 1979
  • The kinetics of the solvolysis of 2-furoyl chloride and 2-thenoyl chloride in $MeOH-H_2O,\;EtOH-H_2O,\;(Me)_2CO-H_2O,\;MeCN-H_2O$ and MeCN-MeOH has been investigated. The rates were faster in protic solvents than in aprotic solvents. This was caused by the bond breaking of leaving group through hydrogen-bonding solvation of protic solvents. In MeCN-M$\'{e}$OH the rate in MeOH rich solvents was faster than in MeCN rich solvents by the specific solvation of alcoholic hydrogen and there was a maximum rate of reaction at MeOH mole fraction of 0.8. The reaction rates of solvolysis were considerably slower than those of benzoyl chloride owing to the electron withdrawing effect of thienyl and furyl groups. It was concluded that solvolytic reaction proceeds via a dissociative $S_N2$ mechanism in which bond-breaking precedes bond-formation at the transition state.

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Solvent Extraction of Polyethylene Glycol by Ethanol in Powder Injection Molded Compacts (분말사출성형체에서 에탄올에 의한 폴리에틸렌글리콜의 용매추출)

  • 조태식
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.665-670
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    • 2001
  • The solvent extraction of polyethylene glycol (PEG) by ethanol has been studied for the powder injection molded compacts of Sr-ferrite/PEG/carnauba wax/HDPE. The extraction rate of PEG is sensitively proportional to the solvent temperature whereas it is inversely proportional to the contents of PEG, the molecular weight of PEG. and the specimen thickness. The high extraction rate of PEG is achieved under the following conditions: solvent temperature of $70^{\circ}C$, PEG contents of 30%, and PEG molecular weight of 400 g/mol. In the early stage of solvent extraction, the non-linear relationship between the extraction rate and the square root of the extraction time indicates that the extraction of PEG does not follow the Fickian behavior. At extraction times longer than 180 min. however, the extraction of PEG follows the Fickian behavior. The extraction fate of PEG by ethanol is about$1.0{ imes}10^{-6}g/cm^2sec$ enough for common applications.

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국내산 홍화씨 부위별추출물의 이화학적특성, serotonin화합물 및 acacetin의 함량 비교

  • 김준한;김종국;강우원;김귀영;박필숙;박모라;문광덕
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 2003.10a
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    • pp.154-154
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    • 2003
  • 국내산 홍화씨를 부위별(Whole, Coat and Endosperm)로 분리한 후 추출용매, 볶음조건, 효소가수분해 등의 처리조건을 달리하여 추출된 추출물의 이화학적특성과 기능성성분 함량을 분석, 비교하였다. 홍화씨 부위별추출물의 고형분함량은 60%에탄올배유부분추출물이 11.29%로, 19$0^{\circ}C$, 30분 볶음처리배유추출물이 14.53%로, amyloglucosidase 처리배유추출물이 24.21%로 높은 고형분이 추출되었다. 총페놀함량은 추출용매의 에탄올농도가 증가함에 따라 증가하는 경향이었고, 80% 에탄올점질추출물이 965mg%로 가장 높았으며, 21$0^{\circ}C$, 30분 볶음처리껍질추출물이 756 mg%로, celluase처리껍질추출물이 1170mg%로 높은 함량이었다. 총플라보노이드함량은 80%에탄올전체추출물이 317 mg%로, 21$0^{\circ}C$, 30분 볶음 처리배유추출물이 488 mg%로, $\beta$-amylase 처리전체추출물이 554 mg%로 높은 함량이었다. 유리당 중 sucrose함량은 21$0^{\circ}C$, 10분 볶음처리배유추출물이 123.4 mg%로, 60%에탄올배유추출물이 57.0 mg%로, Celluase 처리배유추출물이 67.1 mg%로 가장 높은 함량이었고, 또한 glucose, fructose, xylose 및 arabinose 등도 함유하고 있었다. 유기산 중 citric acid 함량은 20%n 에탄올배유추출물이 243.3 67.1 mg%로, 21$0^{\circ}C$, 30분 볶음처리전체추출물이 76.3 mg%로, amyloglucosidase 처리배유추출물이 699.3 mg%로 가장 높은 함량이었고, 또한, oxalic, malic, succinic, acetic 및 fumaric acid 등도 확인되었다. Serotonin 화합물 중 serotonin- I 함량은 100% 에탄올껍질추출물이 431 mg%로, 21$0^{\circ}C$, 10분 볶음처리껍질추출물이 192 mg%로, amyloglucosidase 처리껍질추출물이 256 mg%로 가장 많았다. 또한, Serotonin-II함량은 100%에탄올껍질추출물이 763 mg%로, 17$0^{\circ}C$, 10분 볶음처리전체추출물이 312 mg%로, amyloglucosidase 처리껍질추출물이 456 mg%로 가장 많았다. Acacetin 함량은 80%에탄올배유추출물이 34.9 mg%로, 21$0^{\circ}C$, 30분 볶음처리배유추출물이 221.0 mg%로, amyloglucosidase 처리배유추출물이 27.8 mg%로 가장 많았다.

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Solvent Extraction of Pentachlorophenol(PCP) from PCP-treated Wood (오염화석탄산(PCP)으로 방부 처리된 목재로부터 PCP의 용매추출)

  • Lee, Jong-Chol;Choi, Soo
    • Korean Chemical Engineering Research
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    • v.44 no.2
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    • pp.227-233
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    • 2006
  • Solvent extraction of pentachlorophenol (PCP) from wood chips of the PCP-treated ammunition box has been studied using methanol, ethanol and acetonitrile. Experimental variables were chosen as the composition of solvents, the ratio of solvent per dried wood, size of the substance, extraction temperature and sonication applied to the samples. The average concentration of PCP was 720 ppm and methanol was the most effective for PCP extraction. Above 99% of PCP were removed from the sample (initial concentration of PCP; 1297 ppm) within 2 h at room temperature by methanol. The minimal ratio of methanol per dried wood chip(v/w) was 10. Type of substances(chip or sawdust), extraction temperature and sonication showed little effects on PCP extraction.