• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.63-65
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• 1998

1. Introduction : Atmospheric discharge of VOC-contaminated streams in chemical plants and air streams from chemical processes poses a serious environmental problem and entails large financial losses. Such emissions may be reduced by i) adsorption process, ii) absorption process and iii) incineration process. These processes only forbids the air pollutions. Throughout the recent decade, another technique-membrane process has emerged. The separation and recovery of organic vapors by membrane process may have great economic potential. Most of the published research works on the separation of organic vapors from air were performed using silicon rubber membranes. However, it is very difficult to fabricate very thin membranes with less than 1 $u m thickness. Plasma polymerization could be a good technique to generate a thin polymer film. The objective of this work is to find out the optimum condition of plasma polymerization for producing VOC separation membrane. For the objective, composite membranes are prepared through plasma polymerization of hexamethyldisiloxane onto porous substrates under different conditions. The membrane is then subjected to the permeation of permanent gases and VOCs to find the correlations between the physical properties of the penetrant and permeability and selectivity.

• Journal of the Korean Ceramic Society
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• v.50 no.4
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• pp.301-307
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• 2013

SiC hollow fiber was fabricated by curing, dissolution and sintering of Al-PCS fiber, which was melt spun the polyaluminocarbosilane. Al-PCS fiber was thermally oxidized and dissolved in toluene to remove the unoxidized area, the core of the cured fiber. The wall thickness ($t_{wall}$) of Al-PCS fiber was monotonically increased with an increasing oxidation curing time. The Al-PCS hollow fiber was heat-treated at the temperature between 1200 and $2000^{\circ}C$ to make a SiC hollow fibers having porous structure on the fiber wall. The pore size of the fiber wall was increased with the sintering temperature due to the decomposition of the amorphous $SiC_xO_y$ matrix and the growth of ${\beta}$-SiC in the matrix. At $1400^{\circ}C$, a nano porous wall with a high specific surface area was obtained. However, nano pores grew with the grain growth after the thermal decomposition of the amorphous matrix. This type of SiC hollow fibers are expected to be used as a substrate for a gas separation membrane.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.374-381
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• 1997

Ceramic membranes are prepared by using molding method of the glass materials, ceramic-silicone composite membranes are synthesized with immersing silicone compound of sodiumate, $S_3$-Al, S3and we investigated the properties of gas permeation. Ceramic membranes and ceramic-sodiumate membranes that has been prepared were identified as porous structure and ceramic-$S_3$-Al membranes and ceramic-$S_3$ membranes were showed with dense structure by immersion of silicone compounds. Gas permeation properties through the ceramic membranes and ceramic-sodiumate membranes decreased with increasing temperature and linearly increased with increasing pressure, ceramic-$S_3$-Al membranes and ceramic-$S_3$ membranes increased with increasing temperature and pressure effect was low. Permeation rate was found out high value with ceramic membranes and in order of ceramic-sodiumate membranes, ceramic-$S_3$-Al membranes and ceramic-$S_3$ membranes, but selectivity reversed in the order. Gas permeation mechanism through the ceramic membranes and ceramics-sodiumate composite membrane decreased with increasing temperature, suggesting an Knudsen diffusion mechanism, but ceramic-$S_3$-Al composite membranes and ceramic-$S_3$ composite membranes showed an activated diffusion by which gas permeation rates through the membranes increased with an increase in temperature.