• Title/Summary/Keyword: Silica Films

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Dependence of Surface Morphology of Transparent Hydrophobic Anti-Reflective Coating (투명 발수 반사방지 코팅의 표면 형상 의존성)

  • Kim, Ki-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.771-776
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    • 2017
  • The cover glass of mobile displays and photovoltaic cells needs a functional coating, such as an anti-reflection and self-cleaning coating. Numerous studies have been conducted on the engineering application of biomimetic functional surfaces, such as moth eye and lotus leaf Anti-reflection coantings of silica nanoparticles could enhance the light transmittance. $TiO_2$ photocatalyst coatings have been applied to self-cleaning functional films. In this study, transparent hydrophobic anti-reflective coatings consisting of thin layers of $SiO_2/TiO_2$ nanoparticles were fabricated on a slide glass substrate by the sol-gel process and dip-coating process. The dependence of the surface morphology of the functional coatings was investigated by the atomic force microscopy (AFM), contact angle measurement, and UV-visible spectroscopy. It was found that the coating of $TiO_2$ nanoparticles exhibited a high average transmittance comparable to that of the bare slide glass substrate in the visible light range. The bi-layered functional coating of 7 nm $SiO_2$/7nm $TiO_2$ nanoparticles exhibits a transparent hydrophobic surface with a contact angle of $110^{\circ}$ and an improvement of the average transmittance of 2.3% compared to the bare slide glass substrate in the visible light range.

Growth of Zeolite-X Crystals on Metal Sieves Surface by Continuous Crystallization Method (연속적인 결정화 방법에 의한 금속 지지체상에서 Zeolite-X의 결정성장)

  • Park, Jeong-Hwan;Suh, Jeong-Kwon;Jeong, Soon-Yong;Lee, Jung-Min;Doh, Myung-Ki
    • Applied Chemistry for Engineering
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    • v.8 no.6
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    • pp.939-944
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    • 1997
  • The films of zeolite X on the surface of metal sieve were prepared by continuous crystallization method. It is known that the growth of zeolite crystal on the surface of metal is mainly dependent on the surface composition of metal sieve. In the present work, the zeolite nuclei could be easily formed as Cr content on the metal surface was removed by acid treatment. In order to investigate the proedure growing of zeolite crystal by the continuous crystallization method, the composition of zeolite X($6.36Na_2O-Al_2O_3-5.3SiO_2-190.8H_2O$)was supplied every 12hour. Then the mechanism and inter-relationship between the metal surface and nucleation are investigated. The results show that as the content of silica increases in the gel mixture, the nuclei of zeoilite are easily formed on the metal surface. Also, it was confirmed that the particle of zeolite stuck on the metal surface continues the linear growth. The particles are combined by the reaction of polycondensation, and finally become the shape of crystal. The sample synthesized by the film type was confirmed as zeolite X by the analyses of SEM and XRD.

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