• Title/Summary/Keyword: nanosized

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Stability and Environmental Safety of a Nanosized Agroformulation by Using Gamma-irradiation Technique (감마선을 이용하여 제조한 농업용 나노제제의 보존성 및 환경안전성)

  • Park, Hae-Jun;Kim, Hwa-Jung;Choi, Jin-Su
    • Journal of Radiation Industry
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    • v.7 no.2_3
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    • pp.171-176
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    • 2013
  • In previous study, the novel nanosized curdlan-silica complex for a sustain-releasing effect was developed by using gamma-irradiation. It can be applicable to use in various sustainr-eleasing formulation in agriculture industry. This study was conducted to investigate its storage stability and environmental toxicity in an accelerated condition. The complex samples were treated with high temperature condition ($65^{\circ}C$) during 3 weeks, and then sustain-releasing property of complex was verified thereby using Ion Chromatography on a weekly basis. The morphology of the complex was characterized using scanning electron microscopy (SEM). Results of Ion Chromatography analysis showed that sample treated for 3 weeks was similar to sustain-releasing pattern of non-treatment sample. We verify concluded that the complex is able to keep its sustain-releasing property and sustained-releasing in 3 years. Also the formulation has no environmental toxicity.

Preparation and Characterization of Spherical Carbon Composite for Use as Anode Material for Lithium Ion Batteries

  • Ahn, Byoung-Hoon;Lee, Sung-Man
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1331-1335
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    • 2010
  • A novel spherical carbon composite material, in which nanosized disordered carbons are dispersed in a soft carbon matrix, has been prepared and investigated for use as a potential anode material for lithium ion batteries. Disordered carbons were synthesized by ball milling natural graphite in air. The composite was prepared by mixing the ball-milled graphite with petroleum pitch powder, pelletizing the mixture, and pyrolyzing the pellets at $1200^{\circ}C$ in an argon flow. The ballmilled graphite consists of distorted nanocrystallites and amorphous phases. In the composite particle, nanosized flakes are uniformly distributed in a soft carbon matrix, as revealed by X-ray diffractometer (XRD) and transmission electron microscopy (TEM) experiments. The composite is compatible with a pure propylene carbonate (PC) electrolyte and shows high rate capability and excellent cycling performance. The electrochemical properties are comparable to those of hard carbon.

Hydrothermal Synthesis of Nanosized Sulfated Zirconia as an Efficient and Reusable Catalyst for Esterification of Acetic Acid with n-Butanol

  • Yu, Shengjian;Jiang, Pingping;Dong, Yuming;Zhang, Pingbo;Zhang, Yue;Zhang, Weijie
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.524-528
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    • 2012
  • A kind of nanosized sulfated zirconia was prepared by a hydrothermal method, and full characterized by XRD, TEM, BET, TGA, and FTIR. Its catalytic activity was evaluated in the esterification reactions, including the testing of the catalytic reusability and the optimization of reaction conditions. The obtained catalyst was revealed to be highly efficient solid catalyst for the esterification of acetic acid with n-butanol, presenting the advantages of high conversion and selectivity, easy recovery, and steady reusability.

Preparation and characterization of nanosized hollow silica in the presence of aluminum isopropoxide

  • Nguyen, Ngoc Anh Thu;Kim, Hyun-Ik;Kim, Sang Hern
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.3
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    • pp.421-427
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    • 2016
  • Nanosized hollow silica was prepared by $St{\ddot{o}}ber$ method in the presence of aluminum isopropoxide. The mixture of polyelectrolytes such as poly(sodium 4-styrene sulfonate)(PSS) and polyacrylic acid(PAA) were used as templates. Tetraethylorthosilicate(TEOS) and aluminum isopropoxide were used as precursors for silica and alumina, respectively. The function of aluminum isopropoxide is to increase the porosity of silica shell. The characterizations of hollow silica were examined by TEM(transmission electron microscopy), TGA(thermogravimetric analysis), BET(Brunauer Emmett Teller), Energy-dispersive X-ray spectroscopy(EDS), and FT-IR spectrum. It was found that the shell thickness of hollow silica was around 8 nm and the core diameter was around 20 nm by TEM.

Synthesis and Characterization of Nanosized MnxFe2O4 Powders by Glycothermal Process

  • Bae, Dong-Sik;Kim, Eun-Jung;Lee, Hae-Won;Han, Kyong-Sop
    • Journal of the Korean Ceramic Society
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    • v.39 no.10
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    • pp.903-906
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    • 2002
  • Nanosized $Mn_xFe_2O_4$ powders were prepared in ethylene glycol solution under mild temperature and pressure conditions by precipitation from metal nitrates with aqueous potassium hydroxide. The average size and distribution of the synthesized $Mn_xFe_2O_4$ powders was about 20 nm and broad, respectively. The phase of synthesized particles was crystalline reacted at 200${\circ}C$ for 6h. The magnetic properties of the synthesized $Mn_xFe_2O_4$ powders were about 35-60 (emu/g) with superparamagnetic character.