• Title/Summary/Keyword: 나노분말 합성

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Synthesis of Silica Nanopowder via Change in Polymer Gel Concentration (고분자 젤 농도변화에 의한 실리카 나노분말의 합성)

  • Kim, Ji-Kyung;Lee, Sang-Geun;Kwon, Jae-Youl;Seo, Geum-Seok;Park, Seong-Soo;Park, Hee-Chan
    • Journal of the Korean Ceramic Society
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    • v.42 no.3 s.274
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    • pp.205-210
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    • 2005
  • Nanoscale silica powder was synthesized from $SiO_2$ precursor solution using Tetraethyl Orthosilicate (TEOS) by polyacrylamide gel method. This process was of simplicity and provided ultrafine powders at relatively low calcination temperatures because polymer network could inhibit aggregation of $SiO_2$ powder. The particle size of Si02 powder was affected by the concentration of ammonium persulphate and N, N'-methylene-bis-acrylamide(BIS) in the gel precursor. The particle size decreased with increasing ammonium persulphate and was mininum size of 10 nm at 0.01 M. Also, the size decreased with increasing BIS concentration and was 5 nm at its concentration of 0.05 M.

Characteristics of Crystallinity and Morphology of Barium Titanate Particles Prepared by Spray Pyrolysis (분무열분해 공정에 의해 합성된 바륨 티타네이트 분말의 결정화 및 형태 특성)

  • Lee, Kyo Kwang;Jung, Kyeong Youl;Kim, Jung Hyun;Koo, Hye Young;Ju, Seo Hee;Kang, Yun Chan
    • Korean Chemical Engineering Research
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    • v.43 no.4
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    • pp.517-524
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    • 2005
  • Barium titanate ($BaTiO_3$) particles were prepared by spray pyrolysis from spray solution containing organic additives. The effects of the type and amount of organic precursors on the crystal structure and morphology of the $BaTiO_3$ particles were investigated. It was found that the morphology of $BaTiO_3$ particles before and after calcination depended on the type of organic additives such as citric acid, ethylene glycol and polyethylene glycol. Among these organic additives, citric acid was the most effective to prepare $BaTiO_3$ particles with nano-structured morphology consisting with uniform size nanometer particles after calcination. It was also found that the phase transformability of the metastable cubic phase to the tetragonal one during calcination could be improved by increasing the content of citric acid in the spray solution. As a result, $BaTiO_3$ particles prepared from spray solution containing high concentration of citric acid had good tetragonality, uniform and fine size, and high BET surface area after calcination. $BaTiO_3$ particles prepared by spray pyrolysis had nanometer size and uniform morphology after simple ball milling process.

이달의 과학자 - 한양대 공학대 금속재료공학과 '이재성 교수'

  • Korean Federation of Science and Technology Societies
    • The Science & Technology
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    • v.32 no.6 s.361
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    • pp.22-23
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    • 1999
  • 21세기 첨단기술로 다기능성 금속과 세라믹 나노입자 재료기술이 부상하고 있다. 한양대 금속재료공학과 이재성교수는 활발한 국제적 협력을 바탕으로 나누구조재료에 관한 연구를 계속하고 있다. 현재 국제 나노구조재료학회 국제상임위원으로 한국을 대표하고 있는 이교수는 '나노입자분말 합성기술 및 치밀화 기술개발과 다기능성 나노벌크재료기술을 핵심기술로 발전시켜 나갈 계획"이라고 강조했다.

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