• 제목/요약/키워드: Chemical vapor condensation

검색결과 79건 처리시간 0.02초

흡착질의 증기압이 흡착에 미치는 영향 (Effect of Vapor Pressure of Adsorbate on Adsorption Phenomena)

  • 김상원;권준호;강정화;송승구
    • 한국환경과학회지
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    • 제17권1호
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    • pp.67-75
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    • 2008
  • Adsorption process is largely influenced by pore structures of adsorbents and physical properties of adsorbates and adsorbents. The previous studies of this laboratory was focused on the role of pore structures of adsorbents. And we found some pores of adsorbates which have larger pore diameters than the diameter of adsorbate are filled with easily. In this study the effects of physical and chemical properties of adsorbates and adsorbents, such as pore size distribution, vapor pressure on adsorption were investigated more thoroughly at the concentration of adsorbate of 1000 ppm. The adsorption in the pore ranges of $2{\sim}4$ times of adsorbates's diameter could be explained by space filling concept. But there was some condensation phenomena at larger pore ranges. The errors between the adsorbed amount of non-polar adsorbates and the calculated amounts by considering factors were found to be 44.46%, positively, and -142%, negatively. When vapor pressure is considered, the errors between the adsorbed amount of non-polar adsorbates and the calculated amounts were in the range of $1.69%{\sim}32.25%$ positively, and negatively $-1.08%{\sim}-63.10%$.

활성탄의 기공구조에 따른 아세톤 증기와 톨루엔 증기의 흡착 및 탈착특성 비교 (Comparison of Adsorption and Desorption Characteristics of Acetone Vapor and Toluene Vapor on Activated Carbons According to Pore Structure)

  • 이송우;나영수;안창덕;이민규
    • 한국환경과학회지
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    • 제21권10호
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    • pp.1195-1202
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    • 2012
  • The purpose of this work is to study the adsorption and desorption characteristics of acetone vapor and toluene vapor from adsorption tower in the VOCs recovery device. The six kinds of activated carbon with different pore structures were used and the adsorption and desorption characteristics were compared according to pore structure, desorption temperature, and adsorption method, respectively. Adsorption capacity of acetone vapor and toluene vapor by batch method was higher than that by dynamic method. Especially, activated carbon with medium-sized or large pores had more difference in adsorption capacity according to adsorption methods as a result of gradually condensation of vapors on relatively mesopore and large pores. Activated carbons with relatively large pores and relatively small saturated adsorption capacity had excellent desorption ability.

INFRARED ABSORPTION MEASUREMENT DURING LOW-TEMPERATURE PECVD OF SILICON-OXIDE FILMS

  • Inoue, Yasushi;Sugimura, Hiroyuki;Takai, Osamu
    • 한국표면공학회지
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    • 제32권3호
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    • pp.297-302
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    • 1999
  • In situ measurement of infrared absorption spectra has been performed during low-temperature plasma-enhanced chemical vapor depositiion of silicon-oxide films using tetramethoxysilane as a silicon source. Several absorption bands due to the reactant molecules are clearly observed before deposition. In the plasma, these bands completely disappear at any oxygen mixing ratio. This result shows that most of the tetramethoxysilane molecules are dissociated in the rf plasma, even C-H bonds. Existence of Si-H bonds in vapor phase and/or on the film surface during deposition has been found by infrared diagnostics. We observed both a decrease in Si-OH absorption and an increase in Si-O-Si after plasma off, which means the dehydration condensation reaction continues after deposition. The rate of this reaction is much slower than the deposition ratio of the films.

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