• Title/Summary/Keyword: Aluminum alkoxide

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Preparation and Surface treatment of Spherical $BaMgAl_{10}O_{17}:Eu^{2+}$ phosphor

  • Seo, Kyoung-Soo;Lee, Dae-Won;Jung, Ha-Kyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1079-1082
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    • 2004
  • Dense $BaMgAl_{10}O_{17}:Eu^{2+}$ phosphor particles with a spherical shape have been synthesized through spray pyrolysis method using basic aluminum nitrate precursor as a spray solution. Also, a thin layer of silica on the surface of $BaMgAl_{10}O_{17}:Eu^{2+}$ particles were coated by hydrolysis reaction of alkoxide sources with the particles. The correlation between PL intensity and surface treatment by coating for the dense $BaMgAl_{10}O_{17}:Eu^{2+}$ particles have been investigated.

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Co2+ Adsorption Characteristics of Al2O3-TiO2 Composite Oxide Prepared by Hydrolysis of Metal Alkoxide (금속 알콕사이드의 가수분해법으로 제조한 Al2O3-TiO2 복합옥사이드의 Co2+ 흡착 특성에 관한 연구)

  • Ryu, Jae-Chun;Yang, Hyun-Soo;Kim, Yu-Hwan;Sung, Ki-Woung;Kim, Yong-Ik
    • Applied Chemistry for Engineering
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    • v.7 no.6
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    • pp.1192-1203
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    • 1996
  • $Al_2O_3-TiO_2$ composite oxide adsorbents which could be applied in high-temperature water were prepared by hydrolysis of aluminum and titanium alkoxide. The prepared adsorbents were calcined at $600{\sim}1400^{\circ}C$ and in order to investigate the various properties - the transition of crystals, thermal properties, and specific surface area, X-ray diffractometry, thermal analysis, FT-IR, SEM and BET method were employed. And the $Co^{2+}$ adsorption characteristics of these adsorbents in high-temperature water were investigated by batch adsorption experiment in a stirred autoclave. Since the adsorption of $Co^{2+}$ on the $Al_2O_3-TiO_2$ adsorbents was irreversible endothermic in the temperature range of $150{\sim}250^{\circ}C$, the standard enthalpy changes of 26, 43, and 80 mol% of $TiO_2$ on $Al_2O_3$ were in the range of $16.5{\sim}26.0kJ{\cdot}mol^{-1}$. The adsorbent of 26 mol% of $TiO_2$ on $Al_2O_3$ which was calcined at $600^{\circ}C$ for 2 hours showed the adsorption amount of $0.1674meq{\cdot}g^{-1}$ in the high temperature water at $250^{\circ}C$.

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Change of Particle Size of Spherical Alumina Powders Prepared by Emulsion Method in the Region of Low Hydroxypropylcellulose Concentration (저농도의 HPC 영역에서 에멀젼법에 의해 제조된 구형 알루미나 분말의 입자 크기 변화)

  • Ahn, C.W.;Park, K.S.;Yoo, H.S.;Cho, K.;Lee, Y.W.;Yang, M.S.
    • Journal of the Korean Ceramic Society
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    • v.32 no.5
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    • pp.594-600
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    • 1995
  • Spherical alumina gel powders were produced by hydrolysis of aluminum sec-butoxide (Al(sec-OC4H9)3) in a n-octanol/acetonitrile mixed solvent. The enlargement of particle size was induced by increasing HPC (hydroypropylcellulose) concentration (0.005, 0.1, and 0.05 g/ι) and emulsion-state aging time (10 min and 360 min). Mean particle sizes of dried alumina gel powders increased from 1.4 ${\mu}{\textrm}{m}$ to 3.5${\mu}{\textrm}{m}$ at 10-min emulsion-state aging time and from 1.9${\mu}{\textrm}{m}$ to 4.1${\mu}{\textrm}{m}$ at 360-min emulsion-state aging time as HPC concentration increased from 0.005 g/ι to 0.05 g/ι. At the same HPC concentration, particle size of dried alumina gel powder increased with increasing of emulsion-state aging time from 10 min to 360 min. The increase in the average particle size of dried alumina gel powder with increase in HPC concentration was interpreted as the enlargement of particles from alkoxide emulsions unprotected by HPC. The produced dried gel powder calcined at 115$0^{\circ}C$ for one hour transformed to $\alpha$-alumina.

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