• Title/Summary/Keyword: Chemical Activation

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Pore Structure Characterization of Poly(vinylidene chloride)-Derived Nanoporous Carbons

  • Jung, Hwan Jung;Kim, Yong-Jung;Lee, Dae Ho;Han, Jong Hun;Yang, Kap Seung;Yang, Cheol-Min
    • Carbon letters
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    • v.13 no.4
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    • pp.236-242
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    • 2012

  • Poly(vinylidene chloride) (PVDC)-derived nanoporous carbons were prepared by various activation methods: heat-treatment under an inert atmosphere, steam activation, and potassium hydroxide (KOH) activation at 873, 1073, and 1273 K. The pore structures of PVDC-derived nanoporous carbons were characterized by the $N_2$ adsorption technique at 77 K. Heat treatment in an inert atmosphere increased the specific surface area and micropore volume with elevating temperature, while the average micropore width near 0.65 nm was not significantly changed, reflecting the characteristic pore structure of ultramicroporous carbon. Steam activation for PVDC at 873 and 1073 K also yielded ultramicroporosity. On the other hand, the steam activated sample at 1273 K had a wider average micropore width of 1.48 nm, correlating with a supermicropore. The KOH activation increased the micropore volume with elevating temperature, which is accompanied by enlargement of the average micropore width from 0.67 to 1.12 nm. The average pore widths of KOH-activated samples were strongly governed by the activation temperature. We expect that these approaches can be utilized to simply control the porosity of PVDC-derived nanoporous carbons.

  • https://doi.org/10.5714/CL.2012.13.4.236 인용 PDF KSCI

The Growth Kinetics of Tin Oxide Films from Tetramethyltin

  • 이상운;윤천호
    • Bulletin of the Korean Chemical Society
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    • v.20 no.9
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    • pp.1031-1034
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    • 1999

  • Tin oxide films have been grown employing the chemical vapor deposition technique under reduced pressure conditions using tetramethyltin as the precursor and oxygen as the oxidant. An activation energy derived for the deposition reaction under representative deposition conditions has a value of 89±3 kJ mol-1, suggesting a typical kinetic control. Deposition rates of tin oxide films exhibit a near first order dependence on tetramethyltin partial pressure and a zeroth order dependence on oxygen partial pressure. This study provides the first quantitative information about the growth kinetics of tin oxide films from tetramethyltin by the cold-wall low-pressure chemical vapor deposition.

  • https://doi.org/10.5012/bkcs.1999.20.9.1031 인용 PDF