• Title/Summary/Keyword: Nano powder synthesis

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Synthesis and Characterization of Middle Infrared Transmission ZnS Ceramics by Heat Treatment Time (열처리 시간에 따른 중적외선 투과 ZnS 세라믹의 합성과 특성)

  • Kwon, Tae-Hyeong;Yeo, Seo-Yeong;Park, Chang-Sun;Kim, Chang-Il;Hong, Youn-Woo;Paik, Jong-Hoo
    • Journal of Sensor Science and Technology
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    • v.26 no.5
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    • pp.360-365
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    • 2017
  • In this study, a heat treatment process was applied to ZnS nano-powder to improve the optical properties of ZnS ceramic, and the characteristics of heat treatment time were studied. The ZnS nano-powders were synthesized by hydrothermal synthesis. The heat treatment was carried out at $550^{\circ}C$ for 0.5, 1, 2, and 4 hours in a vacuum atmosphere ($10^{-2}torr$). X-ray diffraction and scanning electron microscope analyzes confirmed the change of crystal phase and grain size to confirm the structural change with heat treatment time. The heat treated ZnS nano-powder was sintered by hot pressing, and the change of optical properties of the ZnS ceramic was analyzed by infrared spectroscopy.

Synthesis and Dispersion Stabilization of Indium Tin Oxide Nanopowders by Coprecipitation and Sol-Gel Method for Transparent and Conductive Films

  • Cho, Young-Sang;Hong, Jeong-Jin;Kim, Young Kuk;Chung, Kook Chae;Choi, Chul Jin
    • Korean Journal of Metals and Materials
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    • v.48 no.9
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    • pp.831-841
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    • 2010
  • Indium tin oxide (ITO) nanopowders were synthesized by coprecipitation and the sol-gel method to prepare a stable dispersion of ITO nano-colloid for antistatic coating of a display panel. The colloidal dispersions were prepared by attrition process with a vibratory milling apparatus using a suitable dispersant in organic solvent. The ITO coating solution was spin-coated on a glass panel followed by the deposition of partially hydrolyzed alkyl silicate as an over-coat layer. The double-layered coating films were characterized by measuring the sheet resistance and reflectance spectrum for antistatic and antireflective properties.

Plasma Engineering for Nano-Materials

  • Kim, Seong-In;Shin, Myoung-Sun;Son, Byung-Koo;Song, Seok-Kyun;Choi, Sun-Yong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.79-79
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    • 2012
  • A high temperature and a low temperature plasma process technologies were developed and demonstrated for synthesis, hybrid formation, surface treatment and CVD engineering of nano powder. RF thermal plasma is used for synthesis of spherical nano particles in a diameter ranged from 10 nm to 100 nm. A variety of nano particules such as Si, Ni, has been synthesized. The diameter of the nano-particles can be controlled by RF plasma power, pressure, gas flow rate and raw material feed rate. A modified RF thermal plasma also produces nano hybrid materials with graphene. Hemispherical nano-materials such as Ag, Ni, Si, SiO2, Al2O3, size ranged from 30 to 100 nm, has been grown on graphene nanoplatelet surface. The coverage ranged from 0.1 to 0.7 has been achieved uniformly over the graphene surface. Low temperature AC plasma is developed for surface modification of nano-powder. In order to have a three dimensional and lengthy plasma treatment, a spiral type of reactor has been developed. A similar plasma reactor has been modfied for nano plasma CVD process. The reactor can be heated with halogen lamp.

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