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Sintering, Crystallization and Microwave Dielectric properties of a Ceramic Particle Incorporated Glass Powder (세라믹 입자가 혼합된 유리분말의 소결, 결정화 및 고주파 유전특성)

  • 김선영;이경호
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.11a
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    • pp.59-63
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    • 2002
  • Zinc-Magnesium borosilicate 유리에 CaF$_2$입자를 충진재로 첨가하여 혼합체의 소결거동, 결정화 거동 및 최종 소결체의 마이크로파 유전특성을 측정하였다. CaF$_2$첨가는 유리의 점도를 감소 시켜 결정화 및 수축개시온도를 감소시켰다. 이러한 CaF$_2$의 최대 첨가량은 주어진 유리조성에 있어서 15 vol. % 이었다. 이러한 소결성 및 결정화 개시온도의 변화는 모 유리와 CaF$_2$의 반응에 의한 결과로 보여지며 이 반응은 결정상의 변화나 이차상의 형성에는 영향을 미치지 않았다. 따라서 유전율 6.1에 품질계수가 40000GHz 인 CaF$_2$입자를 15 vol.% 첨가시 유전상수는 7.1에서 5.6로 품질계수는 2200에서 5000GHz로 유전특성이 향상되었고 소결온도는 75$0^{\circ}C$이었다.

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Recent Progress on Metal-Organic Framework Membranes for Gas Separations: Conventional Synthesis vs. Microwave-Assisted Synthesis (기체분리용 금속유기구조체 분리막의 최근 연구 동향 및 성과)

  • Ramu, Gokulakrishnan;Jeong, Hae-Kwon
    • Membrane Journal
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    • v.27 no.1
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    • pp.1-42
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    • 2017
  • Metal-organic frameworks (MOFs) are nanoporous materials that consist of organic and inorganic moieties, with well-defined crystalline lattices and pore structures. With a judicious choice of organic linkers present in the MOFs with different sizes and chemical groups, MOFs exhibit a wide variety of pore sizes and chemical/physical properties. This makes MOFs extremely attractive as novel membrane materials for gas separation applications. However, the synthesis of high-quality MOF thin films and membranes is quite challenging due to difficulties in controlling the heterogeneous nucleation/growth and achieving strong attachment of films on porous supports. Microwave-based synthesis technology has made tremendous progress in the last two decades and has been utilized to overcome some of these challenges associated with MOF membrane fabrication. The advantages of microwaves as opposed to conventional synthesis techniques for MOFs include shorter synthesis times, ability to achieve unique and complex structures and crystal size reductions. Here, we review the recent progress on the synthesis of MOF thin films and membranes with an emphasis on how microwaves have been utilized in the synthesis, improved properties achieved and gas separation performance of these films and membranes.