• 제목/요약/키워드: Polymeric complex method

검색결과 40건 처리시간 0.024초

착체중합법에 의한 YBCO 분말합성 (Synthesis of YBCO powder using Polymeric Complex Method)

  • 안재원;한영희;한상철;정년호;이준성;박병삼;오광석;성태현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.499-502
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    • 2002
  • We synthesized Y$\sub$1.8/Ba$\sub$2.4/Cu$\sub$3.4/O$\sub$x/(Y123+Y211+1wt% CeO$_2$) powders using Polymeric Complex method and used raw materials; Y$_2$O$_3$, BaCO$_3$, CuO and CeO$_2$. It was formed by calcination at 850 $^{\circ}C$ for 24h in air. In comparison of solid-state method, sol-gel method etc., synthesis temperature decreased up to 100$^{\circ}C$.

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졸-겔 법에 의한 $\gamma-LiAlO_2$ 화이버의 제조 및 특성 (Preparation and Characteristics of $\gamma-LiAlO_2$ Fibers by the Sol-Gel Method)

  • 현상훈;홍성안;신현철
    • 한국세라믹학회지
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    • 제32권2호
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    • pp.197-208
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    • 1995
  • ${\gamma}$-LiAlO2 fibers for fiber reinforced molten carbonate fuel cell (MCFC) matrix have been produced from LiAlO2 complex polymeric sols using the sol-gel process. The stable and spinnable LiAlO2 sols could be synthesized by mixing LiNO3 alcohol solutions in aluminum complex polymeric sols prepared through the condensationpolymerization reaction of 1 more of aluminum tri-sec-butoxide with 0.55 mole of mixed chelates (mole ratio of acetylaceton/triethanolamine=0.25/0.3). It was found that the viscosity range for fiber-spinning should be higher than 30 poise. The defect-free flexible ${\gamma}$-LiAlO2 fibers with the average tensile strength of 350 MPa could be obtained when the spinned fibers were heat-treated to 120$0^{\circ}C$ on the specified heating schedule after dried at room temperature.

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착체중합법에 의한 (Y,Sm)BCO 분말합성과 단결정 제조 (Synthesis of (Y,Sm)BCOpowder and Fabrication of a single crystal using Polymeric Complex Method)

  • 안재원;최희락;한영희;한상철;정년호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.482-485
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    • 2002
  • We synthesize a (Y,Sm)BCO(its composition is (Y/Sm123+0.4Y/Sm211)+1wt%CeO$_2$) powders using polymeric complex method. (Y,Sm)BCO powders are prepared as heated at 970$^{\circ}C$. For measurement of this characterization, We measure XRD and SEM. We use TSMG method for fabricatlon of (Y,Sm)BCO single crystal. The manufactured VBCO single crystal is measured by a magnetic distribution device using 0.5 Tesla magnet. As the result of this measurement, we find that a trapped magnet fields are 550 Gauss.

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Y123와 Y211분말의 동시 합성과 YBCO 초전도 단결정 제조 (Method of simultaneous synthesize for Y123 and Y211 and fabrication of YBCO single crystal)

  • 안재원;최희락;한영희;한상철;정년호;성태현
    • 한국마이크로전자및패키징학회:학술대회논문집
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    • 한국마이크로전자및패키징학회 2002년도 춘계 기술심포지움 논문집
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    • pp.224-233
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    • 2002
  • A common YBCO powder has been made from a mixture of Y123 and Y211 that heated at different temperatures, respectively. The synthesis temperature of Y211 is lower than Y123. If Y211 has been heated as a synthesis temperature of Y123, a particle size of it may be very coarse. It exist as one of main defects for superconductor. But We simultaneously synthesize a YBCO(its composition is (Y123+0.4Y211)+$lwt%CeO_2$) using polymeric complex method. In the YBCO, the Y123 is synthesized lower temperature than other methodes, and its crystal structure is orthorombic. For measurement of these superconducting properties, we fabricated a YBCO single crystal. The manufactured YBCO single crystal is measured a magnetic distribution device using 0.5Tesla magnet and trapped magnet fields in it are 0.2Tesla.

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고분자 담지제에 의한 청주공단내 공장배기가스의 효율적 처리기술에 관한 연구( II ) - 고분자 담지제의 흡착실험을 중심으로 - (Study on Effective Treatment of Waste Gases in Chung-Ju Industrial Complex with Polymeric Absorbent( II ))

  • 이상혁;이영순;전종한
    • 한국안전학회지
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    • 제8권1호
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    • pp.29-34
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    • 1993
  • Two major hazardous gases. SOx and NOx. are emissioned from fossile fuels. SOx has been removed when oil is refined but NOx hasn't. So NOx is very serious problem in air pollution now There are several technologies to remove NOx. e.g. cooling method. scrubbers method. combustion method, polymer membrane method and adsorbent methods. Polymer membrane and adsorbent methods have good economic merit in removal systems of low content hazard gases. Traditional absorbents are porous silicas, aluminas. active carbon and zeolites. But these absorbents act only physisorption which has less removal performance than chemisorption. In this study. polymeric absorbent which has chemisorption as well as physisorption was analyzed about chemical structure and experimented about optimum operation conditions. The results showed that the chemical structure of the polymeric absorbent was expected as polystyrene having -N-CH$_2$COOH absorbent was revealed about 310$m^2$/g. The molar ratio of absored NO to charged NO in absorption experiments was shown 60% of the polymeric absorbent and 45% of zeolite absorbent at 3$0^{\circ}C$.

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Li과 B이 포함된 폴리머 전구체의 열처리에 의한 Li7La3Zr2O12 고체전해질의 소결조제 합성 (Preparation of Sintering Aid for Li7La3Zr2O12 Solid Electrolyte by Heat-treatment of Polymeric Precursors Containing Li and B)

  • 신란희;류성수
    • 한국분말재료학회지
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    • 제25권2호
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    • pp.151-157
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    • 2018
  • In this study, the compound $Li_3BO_3$ (LBO) is intended to be prepared by a polymeric complex method as a sintering aid for the densification of $Li_7La_3Zr_2O_{12}$ (LLZ) solid electrolyte. A polymeric precursor containing Li and B is heat-treated in an air atmosphere at a temperature range between $600^{\circ}C$ and $800^{\circ}C$. Instead of LBO, the compound $Li_{2+x}C_{1-x}B_xO_3$ (LCBO) is unexpectedly synthesized after a heat-treatment of $700^{\circ}C$. The effect of LCBO addition on sintering behavior and ion conductivity of LLZ is studied. It is found that the LCBO compound could lead to significant improvements in the densification and ionic conductivity of LLZ compared to pure LLZ. After sintering at $1100^{\circ}C$, the density of the LLZ-12wt%LBO composite is $3.72g/cm^3$, with a high Li-ion conductivity of $1.18{\times}10^{-4}Scm^{-1}$ at $28^{\circ}C$, while the pure LLZ specimen had a densify of $2.98g/cm^3$ and Li-ion conductivity of $5.98{\times}10^{-6}Scm^{-1}$.

Dithiocarbamate Chitosan을 Matrix로 이용한 고분자 약물의 개발 : Dithiocarbamate Chitosan-Ca(II)-Tetracycline Complex 의 생성 및 항균성 (Development of Polymeric Drugs Utilizing Dithiocarbamate Chitosan: Formation and Antimicrobial Activities of Dithiocarbamate Chitosan-Ca(II)-Tetracycline Complex)

  • 김윤택;김영미;한석규;정연진;유종호
    • 약학회지
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    • 제39권1호
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    • pp.48-54
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    • 1995
  • Coupling of tetracycline(Tc) to dithiocarbamate chitosan(DTCC) via chelate bond was investigated varying reaction time, concentration, temperature, pH, and Ca(II)/Tc ratio. The amount of Tc bound to matrix increased to give a maximum and decreased as the reaction proceeded. The degree and rate of dissociation of Tc complex were affected by the reaction temperature, and pH. By running the reaction at low temperature and pH, the degree of dissociation was greatly diminished. Properties of drug-release from DTCC-Ca(II)-Tc complex were studied by batch- and flow-method and release of Tc and CA(II) by flow method followed nearly zero-order. DTCC-Ca(II)-Tc showed very prolonged antimicrobial activity compared to that of free Tc.

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졸-겔법에 의한 알루미나 화이버의 ${\gamma}-LiAlO_2$ 코팅 (${\gamma}-LiAlO_2$ Coating on Alumina Fibers by the Sol-Gel Method)

  • 현상훈;홍성안;김완식;신현철
    • 한국세라믹학회지
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    • 제31권11호
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    • pp.1271-1282
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    • 1994
  • The surface of commercial alumina fibers used for reinforcing the MCFC matrix has been coated with ${\gamma}$-LiAlO2 being the same material as the matrix, by the sol-gel method in order to enhance the corrosion resistivity of alumina fibers. Stable LiAlO2 complex polymeric sols for coating was synthesized by mixing aluminum alkoxide polymeric sols with LiNO3 solution. It was found that the LiAlO2 polymeric sol prepared by adding the mixed chelate of acethylacetone and triethanolamine (the mole ratio of AA/TEA = 0.125/0.75) to the 1 mole of the aluminum alkoxide had the excellent stability and coating behavior. The crystalline structure of the dried gel from the ${\gamma}$-LiAlO2 sol was completely transformed into the ${\gamma}$-LiAlO2 at $600^{\circ}C$. The optimum viscosity of the sol for coating the alumina long fibers was 30~40 cP, while it was 12~20 cP in case of the short fiber coating. The ${\gamma}$-LiAlO2 coated alumina fibers without defects fully densified when heat-treated at 120$0^{\circ}C$.

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Polymeric Materials for Molecular Recognition

  • Ki, Chang-Do;Lee, Kang-Won;Chang, Ji-Young
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.172-172
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    • 2006
  • Molecular imprinting constitutes a valuable method of preparing polymeric materials with specific binding properties. The most conspicuous merit of molecular imprinting is that structurally three-dimensional recognition sites can be introduced into a polymer matrix with ease and low cost when compared with the complicated process of biological system for antigen and antibody. We used a thermally reversible bond for the preparation of the monomer-template complex, which allowed us to remove the template easily by means of a simple thermal reaction and to simultaneously introduce various functional groups into the cavity. This method is especially propitious for developing artificial receptors for molecules lacking strongly interactive groups.

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착체중합법을 이용한 ZnO 나노분말의 저온합성 (Low temperature synthesis of ZnO nanopowders by the polymerized complex method)

  • 권용재;김경훈;임창성;심광보
    • 한국결정성장학회지
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    • 제12권5호
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    • pp.229-233
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    • 2002
  • 유기화학적 방법인 착체중합법을 이용하여 나노사이즈의 ZnO 분말을 저온에서 합성하였다. 고분자 전구체는 Zn nitrate hexahydrate를 사용하였고, chelating agent로서 citric acid를 reaction medium으로서 ethylene glycol을 혼합하여 제조하였다. 고분자 전구체를 300~$700^{\circ}C$의 온도범위에서 3시간 동안 하소하였으며, 열분해와 결정화 과정을 TG-DTA, FI-IR과 XRD 등을 이용하여 분석하였다. 결정화 온도에 따른 입자의 형상이나 크기를 SEM, TEM의 분석 및 Scherrer's equation을 이용한 계산을 통하여 관찰 및 비교를 하였다. ZnO의 결정화는 $300^{\circ}C$부터 시작되었고, $400^{\circ}C$에서 완전히 합성되었음을 알 수 있었다. 400~$700^{\circ}C$에서 하소된 ZnO 입자들은 대부분 둥근 형태로 균일하게 분포되었으며, $400^{\circ}C$에서 하소된 분말의 평균입도는 약 30~40nm를 보였다. 일반적으로 온도의 상승에 따라 입경이 증가되는 일반적인 경향이 관찰되었다.