• Journal of the Korean Applied Science and Technology
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• v.21 no.4
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• pp.359-363
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• 2004

Reaction conditions and catalysts were investigated for direct $CF_3I$ synthesis. Optimum reaction temperature was determined by pyrolysis of $CF_3H$ and catalytic reactions. Reactions with changing oxygen concentration were performed. As a result, yield of $CF_3I$ increased with decreasing oxygen concentration. Catalytic activity was changed with the weight ratio of the used metal salts. This result was stemmed from the change in the pore size of activated carbon by the metal salts. The optimum reaction conditions were: $600^{\circ}C$, space velocity of $45hr^{-1}$, and with 7wt% KF/AC catalyst.

• Membrane Journal
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• v.14 no.2
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• pp.99-107
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• 2004

Carbon molecular sieve (CMS) membranes were prepared by pyrolysis of polyimides having carboxylic acid groups and applied to the hydrogen separation. The polymeric membranes having carboxylic acid groups showed different steric properties as compared with polymeric membranes having other side groups ($-CH_3$ and $-CF_3$) because of the hydrogen bond between the carboxylic acid groups. However, the microporous CMS membranes were significantly affected by the decomposable side groups evidenced from the wide angle X-rat diffraction, nitrogen adsorption isotherms, and single gas permeation measurement. Furthermore, the gas separation properties of the CMS membranes were essentially affected by the pyrolysis temperature. As a result, the CMS membranes Prepared by Pyrolysis of polyimide containing carboxylic acid froups at $700^{\circ}C$ showed the $H_2$ permeability of 3,809 Baller [$1{\times}10^{-10}$ H $\textrm{cm}^$(STP)cm/$\textrm{cm}^2$.s.cmHg], $H_2$/$N_2$, selectivity of 46 and $H_2$/$CH_4$ selectivity of 130 while the CMS membranes derived from polyimide showed the H$_2$ permeability of 3,272 Barrer, $H_2$/$N_2$ selectivity of 136 and $H_2$/$CH_4$ selectivity of 177.