• 제목/요약/키워드: SolI

검색결과 308건 처리시간 0.024초

졸겔법에 의한 알루미나 섬유의 제조 (I) 유동학적 특성분석 (The Preparation of Alumina Fiber by Sol-Gel Method (I) Rheological Properties)

  • 최용수;이종혁;이해욱;김창은
    • 한국세라믹학회지
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    • 제32권1호
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    • pp.17-24
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    • 1995
  • The TEA complex polymeric sol was prepared by the alkoxide sol-gel method. The purpsoe of this experiment was to vefity the particle shape in the sol from the investigation of the rheological properties. TEA retarded hydrolysis rate by the reaction with alkoxide enough to make a stable transparent sol in the wide range of composition. From the results of the viscosity change with time, the optimum mole ratio for spinning was selected as 0.5 mole of TEA, 3 mole of H2O and the optimum viscosity was 104 cPs. The rheological behavior of the sol showed that the particle shape in the sol was linear, which was adequate for fiber drawing.

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졸겔법에 의한 알루미나의 제조(I) - 중합 알루미나 졸의 특성 (Preparation of Alumina by the Sol-Gel Process(I) - Characteristics of Polymeric Alumina Sol)

  • 이해욱;김구대;정형진;김창은
    • 한국세라믹학회지
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    • 제28권1호
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    • pp.60-66
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    • 1991
  • The polymeric alumina sol was prepared by partial hydrolysis of aluminum sec-butoxide reacted with acetylacetone and its characteristics was investigated. The effects of alcohol solvent, acetylacetone, and acid concentration to the sol were investigated. FT-IR and Al27-MASNMR were used to study hydrolysis and polymerization reaction of aluminum complex. Synthesized sol showed the characteristics of polymeric alumina sol. To make a clear polymeric alumina sol, the optimum contents of acetylacetone, H2O and alcohol solvent were 0.4-0.6 mole, 0.25-1.25 mole, 3-5 mole per one mole alkoxide respectively. As a result of the Al27-MASNMR analysis, it was noted that hexa-penta-coordinated Al were main structure.

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Streptoverticillium olivoverticillatum에서 분리한 새로운 Type II 제한효소 SolI의 특성 연구 (Characterization of a New Type II Restriction Endonuclease Isolated from streptoverticillium olivoverticillatum)

  • 황혜연;임정빈
    • 미생물학회지
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    • 제32권3호
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    • pp.208-214
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    • 1994
  • 토양으로부터 분리한 방선균주로부터 새로운 type II 제한효소를 분리하여 그 특성을 연구하였다. 이 균주는 수리분석 결과, Streptoverticillium olivoverticillatum으로 동정되었으며, 정제한 제한효소는 SolI이라 명명하였다. SoII은 BamHI의 isoschizomer로서 여섯 개의 염기서열 5'-G $\downarrow$ GATCC- 3'을 인지하며 두 개의 G 염기 사이에서 절단하여 4 base가 돌출된 5'말단을 생성한다. 그러나 BamHI과는 달리, dam methylation 되어 있는 인식 염기서열에는 작용하지 못하였다. Ammonium sulfate 분획(30-65%)과 heparin-agarose, Affi-gel Blue column chromatography를 거쳐 SolI을 부분 정제하였다. SolI은 활성을 보이기 위하여 0.2mM 이상의 $MgCl_2$를 반드시 필요로 하였으며, 다른 cofactor는 요구하지 않았다. NaCl이 없을 때 가장 높은 활성을 가지며 120 mM 이상의 NaCl이 있으면 활성이 완전히 억제되었다. 이 효소의 반응 최적 온도는 $40^{\circ}C$, 최적 pH는 8.6으로 나타났다. Gel filtration chromatography에서의 용출부피 비교로부터 이 효소의 분자량은 약 43,000Da인 것으로 추정된다.

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졸-겔 세라믹 코팅에 의한 스테인레스강의 내산화 및 내식성 향상에 관한 연구;(I) 지르코니아 졸의 합성 및 박막의 제조 (A Study on the Improvement of Oxidation and Corrosion Resistance of Stainless Steel by Sol-Gel Ceramic Coating; (I) Synthesis of Zirconia Sol and Fabrication of Its Thin Film)

  • 김병호;홍권;신동원
    • 한국세라믹학회지
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    • 제31권9호
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    • pp.1060-1068
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    • 1994
  • Stable zirconia sol was prepared from zirconium butoxide Zr(OC4O9)4 as a precursor and ethylacetoacetate(EAcAc) or diethylene glycol(DEG) as a chelating agent under ambient agent under ambient atmosphere by Sol-Gel process. The sythesized sol was coated on 304 stainless steel substrate by dip coating, thereafter zirconia film could be obtained by heat-treatment at $600^{\circ}C$. The characteristics of coating film were determined by FT-IR, XRD, and ellipsometion peak represented Zr-O-Zr bonding of tetragonal phase was shown at 470cm-1. Crystallization of zirconia gel and film from amorphous state to tetragonal phase started at 40$0^{\circ}C$, and then transformed into monoclinic phase around $700^{\circ}C$. Zirconia film coated on 304 stainless steel substrate showed relatively low porosity of 16% when it was coated with 0.4M zirconia sol and thereafter heat-treated at 80$0^{\circ}C$ and the film was densified continuously up to 90$0^{\circ}C$. The zirconia film of 10 nm thick acted as a protective layer against oxidation up to $700^{\circ}C$.

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졸-겔법에 의한 다결정 물라이트 섬유의 제조 (Preparation of Polycrystalline Mullite Fiber Using the Sol-Gel Technique)

  • 김경용;김윤호;이수원;정형진;김구대
    • 한국세라믹학회지
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    • 제26권6호
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    • pp.795-801
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    • 1989
  • The polycrystalline mullite fiber was synthesized from various combination of starting materials including metal alkoxides and colloidal sol by the sol-gel process. The best spinnability was observed in the sol which showed shear thinning and hysteresis (i.e., thixotropic flow), indicating that the network structure was broken down as the shear rate increased. The mullite fiber was polycrystalline after firing and characterized by thermal analysis, XRD, FT-IR spectroscopy, rheological measurements, and SEM.

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Aging 효과가 Sol-gel 공정 기반 CuO 박막 트랜지스터의 전기적 특성에 미치는 영향 (Aging Effects on Electrical Characteristics of Sol-gel Processed CuO Thin Film Transistors)

  • 장재원
    • 한국전기전자재료학회논문지
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    • 제29권9호
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    • pp.527-531
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    • 2016
  • In this study, p-type thin film transistors consisting of CuO channels were fabricated by sol-gel process, with copper (II) acetate monohydrate precursors. At $500^{\circ}C$, the deposited films were fully converted into monoclinic phase CuO. The fabricated CuO thin film transistors deliver field effect mobility in saturation regime of $0.015cm^2/Vs$, and $I_{on}/I_{off}$ of ${\sim}10^3$. The degradation of the performance of the fabricated CuO thin film transistor caused by the exposure to air has been studied.

Sol-gel법으로 제조한 강유전성 Bi3.25La0.75Ti3O12박막의 급속열처리에 따른 전기적 특성에 관한 연구 (A Study on Electrical Properties of Sol-gel Derived Bi3.25La0.75Ti3O12 Thin Films by Rapid Thermal Annealing)

  • 이인재;김병호
    • 한국세라믹학회지
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    • 제40권12호
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    • pp.1189-1196
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    • 2003
  • Sol-gel법으로 강유전성 B $i_{3.25}$L $a_{0.75}$ $Ti_3$ $O_{12}$ (BLT) stock solution을 합성하고 Pt/Ti $O_2$/ $SiO_2$/Si 기판위에 스핀코팅법으로 BLT 박막을 증착하였다. 본 실험에서는 Bi(TMHD)$_3$, La(III)2-Methoxyethoxide, Ti(IV)i-propoxide를 출발물질로 사용하였으며 2-Methoxyethanol을 용매로 사용하였다. 급속열처리(RTA)가 BLT 박막의 결정성장을 촉진시키기 위해 사용되었고, RTA를 실시한 시편과 RTA를 실시하지 않은 시편의 전기적 특성을 비교하였다. RTA를 실시한 후 72$0^{\circ}C$에서 로 열처리 한 BLT 박막의 경우 5V 인가 전압 하에서 2Pr 값은 RTA를 실시하지 않은 경우보다 27% 증가한 20.46$\mu$C/$ extrm{cm}^2$이었다.

졸-겔법에 의한 강유전성 PZT 박막의 제조;(I) 킬레이팅 에이전트를 이용한 안정화 PZT 졸의 합성 및 박막의 제조 (Preparation of Ferroelectric PZT Thin Film by Sol-Gel Processing; (I) Synthesis of Stable PZT Sol Using Chelating Agent and Preparation of Its Thin Film)

  • 김병호;홍권;조홍연
    • 한국세라믹학회지
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    • 제31권7호
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    • pp.804-812
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    • 1994
  • Stable PZT coating sol was prepared using chelating agent, ethylacetoacetate(EAcAc) by sol-gel processing under ambient atmosphere. Through FT-IR spectrum analysis on solution of each reaction step, formation of metal complex was confirmed and prepared PZT sol was stable over several months. Through TG-DTA, XRD, FT-IR spetrum analysis of PZT gel powder, it was understood that the addition of EAcAc could reduce the transition temperature to ferroelectric phase, due to the increased homogeneity by matching the hydrolysis and condensation rates by chelation. Single perovskite phase was obtained by the heat-treatment at 54$0^{\circ}C$ for 30 min. The film was coated on ITO-coated glass substrate by dip coating method. After heat-treatment, PZT thin film had thickness in the range of 20~130 nm. The maximum dielectric constant of its thin film at room temperature and 1 kHz was 128.

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알콕시 실란기능화 양친성 고분자 전구체를 이용한 유-무기 하이브리드 졸 제조 및 이를 이용한 발수 코팅 (Preparation of O-I hybrid sols using alkoxysilane-functionalized amphiphilic polymer precursor and their application for hydrophobic coating)

  • 이대곤;김나혜;김효원;김주영
    • 접착 및 계면
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    • 제20권4호
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    • pp.146-154
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    • 2019
  • 본 연구에서는 소수성 PPO 사슬과 친수성 PEO 사슬들이 동시에 존재하고, 반응성 알콕시 실란기를 가지고 있는 알콕시 실란 기능화 양친성 고분자 전구체 (Alkoxysilane-functionalized Amphiphilic Polymer, AFAP)를 합성하여, 이를 TEOS과의 Hydrolysis- Polycondensation 반응에서 분산안정제 및 반응속도 조절제로 이용하여서 유-무기 하이브리드 나노입자가 안정적으로 분산된 졸 (Sol)을 제조하였다. 제조된 Sol에 불소 함유 실란화합물을 혼합·반응하여서 불소함유 유-무기 하이브리드 Sol을 제조하였고, 이를 유리 기재에 코팅하고 저온 경화를 통해 기재위에 경화필름을 형성하였다. 형성된 경화 필름은 AFAP 및 불소 함유 실란화합물의 첨가량, 용매 종류에 따라서 표면 경도 및 발수 특성이 변화하였다. 최적의 용매 및 불소 함유 실란화합물 첨가량에서 태양전지나 디스플레이에 적용가능한 투명하면서도 견고한 유-무기 하이브리드 형태의 코팅필름 형성이 가능하였다.

솔-젤법에 의한 강유전성 PZT 박막의 제조;(III) 급속열처리방법이 미세구조 및 유전특성에 미치는 영향 (Preparation of Ferroelectric PZT Thin Film by Sol-Gel Processing; (III) Effect of Rapid Thermal Annealing on Microstructures and Dielectric Properties)

  • 김병호;박성호;김병호
    • 한국세라믹학회지
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    • 제32권8호
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    • pp.881-892
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    • 1995
  • Sol-Gel derived ferroelectric PZT thin films were fabricated on ITO/Glass substrate. Two kinds of rapid thermal annealing methods, R-I (six times of intermediate and final annealing) and R-II (one final annealing after six times of intermediate annealing) were used for preparation of multi-coated PZT thin films. 2500$\AA$-thick PZT thin films were obtained by the R-I and R-II methods and characterized by microstructure and dielectric properties. In case of using R-II, the microstructure was finer than that of R-I and there was no distinguishable difference in dielectric properties of PZT thin films between the R-I and R-II methods. But dielectric properties were enhanced by increasing perovskite phase fraction with increasing annealing temperature. Measured dielectric constant of PZT thin film annealed at 62$0^{\circ}C$ using the R-I method was 256 at 1kHz. Its remanant polarization (Pr) and coercive field (Ec) were 14.4$\mu$C/$\textrm{cm}^2$ and 64kV/cm, respectively.

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