• 제목/요약/키워드: material synthesis

검색결과 1,780건 처리시간 0.029초

Isothiazoline 유도체의 합성 및 정제에 관한 연구 (A Study on the Synthesis and Refining of Isothiazoline Derivatives)

  • 성기천;김기준
    • 한국응용과학기술학회지
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    • 제14권2호
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    • pp.93-102
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    • 1997
  • Isothiazoline derivatives is widely used to food, medical drug and industrial goods, cosmetics etcs, and it makes to restrain and to sterilize a breeding of microbe as a preservative and a sterilizing agent. It differs with the raw material of paraoxybenzoic acid derivatives or imidazolydinyl urea to be in use at present, on the efficacy and effect, and has various characteristics. This synthesis makes 3,3'-dithiodipropionic chloride to add a thionyl chloride in 3,3'-dithiodipropionic acid, and 3,3'-dithiodipropionic methyl amide makes to synthesize in a reflux reaction the mono methyl amine to 3,3'-dithiodipropionic chloride. And last synthesis becomes to make chlorination-cyclization molecule doing a reflux reaction in the temperature of $90{\sim}100^{\circ}C$ to mix excessively thionyl chloride and ethylene dichloride to 3,3'-dithiodipropionic methyl amide. The last synthesis material has got in the mixture of 5-chloro-2-methyl-4-isothiazoline-3-one and 2-methyl-4-isothiazoline-3-one, and it is so-called isothiazoline derivatives. The purification of isothiazoline derivatives makes to fuse in ethyl acetate, and makes to decolorize and to deodorize in recrystallization. This experiment has been in synthesis and purification of isothiazoline derivatives, and has tried to measure on the antisepsis and sterilization function of microbe according to pH or content change.

Yttirum Oxyfluoride 원료의 고상합성 및 서스펜션 플라즈마 스프레이 코팅 응용 (Solid-State Synthesis of Yttirum Oxyfluoride Powders and Their Application to Suspension Plasma Spray Coating)

  • 박상준;김형순;이성민
    • 한국재료학회지
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    • 제27권12호
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    • pp.710-715
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    • 2017
  • We synthesized YOF(yttirum oxyfluoride) powders through solid state reactions using $Y_2O_3$ and $YF_3$ as raw materials. The synthesis of crystalline YOF was started at $300^{\circ}C$ and completed at $500^{\circ}C$. The atmosphere during synthesis had a negligible effect on the synthesis of the YOF powder under the investigated temperature range. The particle size distribution of the YOF was nearly identical to that of the mixed $Y_2O_3$ and $YF_3$ powders. When the synthesized YOF powders were used as a raw material for the suspension plasma spray(SPS) coating, the crystalline phases of the coated layer consisted of YOF and $Y_2O_3$, indicating that oxidation or evaporation of YOF powders occurred during the coating process. Based on thermogravimetric analysis, the crystalline formation appeared to be affected by the evaporation of fluoride because of the high vapor pressure of the YOF material.

Preparation and Charecterization of Bromofullerenes in New Stoichiometry

  • Mehrotra, Reema;Lal, Darshan;Tripathi, V.S.;Mathur, G.N.
    • Carbon letters
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    • 제4권4호
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    • pp.175-179
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    • 2003
  • It is well established that halogenated fullerene derivatives act as synthetic intermediates for further substitution via replacement with nucleophlies. In the present work, systematic studies were carried out on the synthesis of bromofullerenes under different experimental conditions. The effect of reaction time on the product formed was observed. We observed the formation of new compound of bromofullerenes in a different stoichiometric ratio i.e., $C_{60}Br_{14}$; in addition to previous reported bromofullerenes in the stoichiometric ratio of $C_{60}Br_6$, $C_{60}Br_8$, and $C_{60}Br_{24}$. The new derivative of bromofullerene was isolated and well characterized by various analytical techniques like FT-IR, TGA, DSC, and elemental analysis. In this paper, detail of the synthesis and characterization of the bromofullerene prepared are described. The yields obtained were better than those reported previously.

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(PIM-co-Ellagic Acid)-기반의 이산화탄소 분리막의 개발 ((PIM-co-Ellagic Acid)-based Copolymer Membranes for High Performance CO2 Separation)

  • 호세인 이크발;허스너 아스몰;김동영;김태현
    • 멤브레인
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    • 제30권6호
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    • pp.420-432
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    • 2020
  • (PIM-1)과 ellagic acid로 만든 랜덤형 공중합체가 간단한 방법으로 합성되었으며, 이산화탄소 분리막에 대한 적용 가능성에 대해서 연구하였다. 이 공중합체의 경우 PIM (polymers with intrinsic microporosity) 고분자의 미세 기공 구조에 기인한 높은 기체 투과도와 평면 구조와 친수성을 갖는 ellagic acid에 기인한 높은 이산화탄소에 대한 선택성에 의해 우수한 이산화탄소 기체 분리 성능을 나타내었다. 즉, 이산화탄소에 대한 투과도 4516 Barrer와 CO2/N2 (> 23~26) 및 CO2/CH4 (>18~19)의 높은 선택성으로 두 쌍의 가스 혼합물에 대해 Robeson 상한(2008)을 초과한 결과를 나타내었다. 이와 같이 PIM-1에 평면구조를 갖는 ellagic acid을 혼입하면 PIM-1의 꼬인 구조를 방해하여 기체 투과성을 향상 시킬 뿐만 아니라 공중합체의 강성과 극성이 증가하여 N2 및 CH4에 대한 CO2의 선택성을 증가시키는 결과를 확인하였다.

Synthesis and characterization of visible light active photocatalytic $TiO_2$

  • Kim, Duk-Su;Park, Kyu-Sung;Kim, Il-Doo;Kim, Ho-Gi
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.1116-1120
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    • 2002
  • Using thermal hydrolysis and hydrothermal treatment, photocatalytic $TiO_2$ powders were synthesized. During the synthesis, the addition of other transition metals such as iron, copper, etc., affected the photocatalytic capability of synthesized powders, and enabled the activation by visible light. To enhance photocatalytic capacity of gas phase decomposition, the rate-determining adsorption rate of pollutant gases were improved via surface modification of $TiO_2$ powders. The surface modifiers were implanted using mechanochemical synthesis of dopants and photocatalytic powders.

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