• 제목/요약/키워드: Various Solvents

검색결과 784건 처리시간 0.019초

호장근 추출액에 의한 염색성(II) -호장근 추출액의 자외 . 가시부 분광 특성 - (The Dyeing Properties of Korean Knotweed Extract( II ) - The UV-visible Spectrophotometric Characteristics of Korean Knotweed Extracts -)

  • 김미숙;최석철
    • 한국염색가공학회지
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    • 제13권5호
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    • pp.298-305
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    • 2001
  • The Purpose of this study was to investigate spectrophotometric characteristics of Korean knotweed extracts. The properties were evaluated by it's extracting solvent, effect of metallic ion, variations of pH values and effect of light exposure. The results were as following; The highest absorbance was found in methanol extract of Korean knotweed, while the lowest absorbance was carbon tetrachloride extract. The UV-vis. spectra of Korean knotweed colors in several solvents showed hypsochromic shift of $n->\pi^*$ transition with the polarity of solvent. Absorbance and peak of UV-vis. spectra of Korean knotweed colors became lower and broader by addition of metallic ion. The light stability in irradiation with xenon ]amp of the color solution with Cu were higher than those of Al and Fe. The UV-vis. spectra of Korean knotweed extracts in various pH values showed bathochromic shift under alkaline condition, and their Peaks disappeared after 5 hours exposure.

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Using Waste Foundry Sands as Reactive Media in Permeable Reactive Barriers

  • 이태윤;박재우
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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    • pp.62-65
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    • 2002
  • Permeable reactive barriers (PRBs) are in-situ barriers constructed in a subsurface to treat contaminated groundwater using various reactive media. The common reactive medium used in PRB is zero-valent iron, which has been widely used to treat chlorinated solvents (i.e., PCE, TCE). A disadvantage of iron media is high cost. In this study, waste foundry sands were tested to determine the feasibility of their use as a low cost reactive medium. Batch and column tests were conducted with TCE to determine transport parameters and reactivity of the foundry sands. The reactivities of foundry sands for common groundwater contaminants are comparable to or slightly higher than those for Peerless iron, a common medium used in PRBs. In addition, the TOC and clay in foundry sands can significantly retard the movement of target contaminant, which may result in lower effluent concentration of contaminant due to biodegradation. In general, PRBs 1-m thick can be constructed with many foundry sands to treat TCE provided the zero-valent iron content in the foundry sand is higher than 1%.

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PTT 섬유의 염색성 (2) - 용제 처리한 PTT 섬유의 염색성 및 물성 - (Dyeing Properties of PTT Fiber (2) - Effect of Solvent Treatment on Dyeing and Physical Properties of PTT Fiber -)

  • 이두환;정동석;김호정;이문철
    • 한국염색가공학회지
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    • 제15권4호
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    • pp.8-16
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    • 2003
  • Poly(trimethylene terephthalate)(PTT) fiber was pretreated with organic solvent/water solution of various compositions. The organic solvents used in this experiment were benzyl alcohol, n-buthanol, and N,N-dimethylformamide(DMF). Density of the fibers were investigated as a measure of crystallite region. The dye uptake increased in the order of pretreatment with hot water < untreated < 5% benzyl alcohol < 100% benzyl alcohol < 90% benzyl alcohol; hot water < untreated $\risingdotseq$ 5% butanol < 100% beutanol < 90% butanol; hot water $\risingdotseq$ 5% DMF < untreated < 90% DMF < 100% DMF. The dye uptake increases with increase of crystallinity. It seems likely that the recrystallization process during the pretreatment with organic solvent/water solutions leads to an increase in the microvoid and then a large increase in the dye uptake. Also the dyeing rate increased and the dyeing transition temperature decreased with the pretreatments. The results obtained are corresponds with the plasticization of the fiber structure formed during the pretreatrnent.

담배연기 응축물중 phenolic fraction의 분리와 확인 (The Identification & Separation of Phenolic fraction in Cigarette Smoke Condensate)

  • 이문수;임흥빈;장기철
    • 한국연초학회지
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    • 제10권1호
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    • pp.49-57
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    • 1988
  • The phenolic compounds were isolated from the cigarette smoke condensate using two immiscible organic solvents by a partition coefficient. Of them, 20 phenolic compounds were identified by GC and GC/MS. The amount of the phenolic compounds was phenol, p-crestol, hydroxybensoic acid in order. And there was no difference in composition of these compound dependent on leaf tobacco . About 70% amount of these compounds were absorbed to cellulose acetate filter used. The contents and composition of these compounds were various in the commercial cigarette.

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혼합용매중(混合溶媒中)에서의 식용(食用) Tar색소(色素)의 해리정수(解離定數)에 관(關)한 연구(硏究) (제 1 보)(第 1 報) -2',4',5',7'- Tetraiodofluorescein Sodium염(鹽)에 대(對)하여- (A Study on the Effects of the Dissociation Constant of Edible Tar Pigment. I)

  • 김박광;이민화;조영미;김길수;문동철
    • Journal of Pharmaceutical Investigation
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    • 제10권3호
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    • pp.14-19
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    • 1980
  • The dissociation constant of erythrosine in the mixed solvent systems of water-alcohols and water-acetone at various pH and in concentration media were determined by spectrophotometric method. Methanol, ethanol, and acetone were employed as solvents and studied the changes of pK values of erythrosine according to the kind and change of concentration of organic solvent which is mixed into water solution. The effect of organic solvent on pK is negligible at 40% while in the case of above 40% mixing, it is not negligible.

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Enantiomer의 분리에 이용될 수 있는 Chelate Resin의 개발 (제1보) -가교 폴리스티렌 Resin Matrix의 염화메칠화에 있어서의 용매효과- (Development of Optically Active Chelate Resin for Direct Resolution of Enantiomers (I) -Solvent Effects in Chloromethylation of Crosslinked Polystyrene Resin Matrix-)

  • 김길수;전동원;박경혜
    • Journal of Pharmaceutical Investigation
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    • 제18권2호
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    • pp.69-81
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    • 1988
  • We studied on the synthesis of chloromethylated polystyrene as a precursor of optically active polymers for direct resolution of optical isomers. Changing the degree of crosslinking and the kind of crosslinking agents, several polystyrene resin matrices were synthesized. The matrices were chloromethylated with methylal and chlorosulfonic acid as chloromethylating agents. The effects of solvents of various dielectric constants on the chloromethylation were quantitavely examined. We also synthesized chloromethylated polystyrene of macroreticular type that retained large surface area and good physical stability. The differences between the macroreticular type and macroporous type were investigated.

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채소 중의 유기인제 및 유기염소제 농약의 단순화된 抽出과 精製 技法에 관한 연구 (A Study on the Simplified Extraction and Cleanup Technique for Organophosphorus and Organochlorine pesticides in Vegetables)

  • 전옥경;이용욱
    • 한국환경보건학회지
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    • 제23권1호
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    • pp.66-73
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    • 1997
  • This procedure describes the method for gas chromatographic determination of 31 organophosphorus and 28 organochlorine pesticides in 10g of spinach, tomato and onion. After the pesticides were extracted with several solvents, the amount of coextractives and recovery rates of acephate and methamidophos were calculated. Samples for organochlorine pesticides were cleaned up with florisil solid phase extraction columns. NaBH$_4$ was added to onion extracts, which contained sulfur compound. All the concentrated extracts were analyzed by gas chromatography with ECD and NPD. The smallest amount of coextractives resulted from the spinach samples extracted with 5% MeOH in ethyl acetate. 5% EOH in ethyl acetate had the highest extractability for acephate and methamidophos and gave the best overall performance as an extraction solvent. The ability of 5% EOH in ethyl acetate to extract various organophosphorus and organochlorine pesticides from spinach, tomato and onion was examined. Recovery of 59 insecticides ranged from 58.0% to 110.5%. The average recoveries of fortified spinach, tomato and onion were 90.08%, 94.54% and 84.90%, respectively.

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Systematic Approaches for Blue Light-emitting Polymers by Introducing Various Naphthalene Linkages into Carbazole Containing PPV Derivatives

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • 제14권5호
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    • pp.258-262
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    • 2013
  • Poly(2,3-naphthalenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene), 2,3-PNCPV, poly(2,6-naphthalene vinylenealt- N-ethylhexyl-3,6-carbazolevinylene), 2,6-PNCPV, and poly(1,4-naphthalenevinylene-alt-N-ethylhexyl-3,6- carbazolevinylene), 1,4-PNCPV were synthesized through the Wittig polycondensation reaction. The conjugation lengths of the polymers were controlled by differently linked naphthalenes in the polymer main chain. The resulting polymers were completely soluble in common organic solvents, and exhibited good thermal stability at up to $400^{\circ}C$. The synthesized polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 357-374 nm and 487-538 nm, respectively. The carbazole and 2,3-linked naphthalene containing 2,3-PNCPV showed a blue PL peak at 487 nm. A single-layer light-emitting diode was fabricated with an ITO/polymer/Al configuration. The electroluminescence (EL) emission of 2,3-PNCPV was shown at 483 nm.

3성분계 유기용제의 인화특성에 관한 연구 (A Study on the Characteristics of Flammability for Organic Solvents of Three Component Systems)

  • 임우섭;목연수;최재욱;최일곤;하동명;조태제
    • 한국안전학회지
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    • 제14권3호
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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.

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다공성 물질에 함침시킨 알콜의 연소특성 (Combustion Characteristics of Immobilized Alcohols in Porous Material)

  • 우인성;황명환
    • 한국안전학회지
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    • 제9권1호
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    • pp.76-82
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    • 1994
  • Combustion phenomena(characteristics) of organic solvents including various alcohols Immobilized on ceramic balls were studied. Experiments were performed by burning methyl, ethyl, and propyl alcohol immobilized on sands (particle size 0.35mm) and coramic balls(particle size 1~5mm) to measure mass burning rate, height burning rate and combustion temperature. The longer time from ignition to extinguishment was resualted from the larger particle size of ceramic balls and the smaller size of ceramic balls exhibited the higher mass burning rate. Of alcohols tested the relative magnitude of facilitation of combustion was methyl >ethyl >propyl. Combustion temperatare of alcohols, without regard to the types of alcohols, was not increased with smaller ceramic balls(up to 3mm of particle size). However, with larger ceramic balls, combustion temperatare of alcohols was increased by 40~5$0^{\circ}C$ and the highest combustion temperatare was obtained with sands(particle size 0.35mm). Also, second rising was occurred at the combustion time of I5-20min. and this second rising time was increased with the smaller particle. These results will be able to be used for petrochemical industries using particles to evaluate the danger of fire and explosion.

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