Permeation Properties of Single Gases ($N_2$, $O_2$, $SF_6$, $CF_4$) through PDMS and PEBAX Membranes

PDMS와 PEBAX 분리막을 통한 단일기체($N_2$, $O_2$, $SF_6$, $CF_4$) 투과 특성

  • Kim, Hanbyul (Center for Water Resources Cycler, Green City Technology Institute, Korea Institute of Science and Technology) ;
  • Lee, Minwoo (Center for Water Resources Cycler, Green City Technology Institute, Korea Institute of Science and Technology) ;
  • Park, Wankeun (Center for Water Resources Cycler, Green City Technology Institute, Korea Institute of Science and Technology) ;
  • Lee, Soonjae (Center for Water Resources Cycler, Green City Technology Institute, Korea Institute of Science and Technology) ;
  • Lee, Hyunkyung (Department of Industrial Chemistry, Sangmyung University) ;
  • Lee, Sanghyup (Center for Water Resources Cycler, Green City Technology Institute, Korea Institute of Science and Technology)
  • 김한별 (한국과학기술연구원, 물자원순환연구단) ;
  • 이민우 (한국과학기술연구원, 물자원순환연구단) ;
  • 박완근 (한국과학기술연구원, 물자원순환연구단) ;
  • 이순재 (한국과학기술연구원, 물자원순환연구단) ;
  • 이현경 (상명대학교 공업화학과) ;
  • 이상협 (한국과학기술연구원, 물자원순환연구단)
  • Received : 2012.04.09
  • Accepted : 2012.06.28
  • Published : 2012.06.29

Abstract

In this study, we investigated permeation of single gas ($N_2$, $O_2$, $CF_4$, and $SF_6$) through flat sheet membrane composed of PDMS (poly-dimethylsiloxane) and PEBAX (polyether block amides). Gas permeation experiment was performed with various feed pressure. Permeability was estimated using permeation flux measured by continuous-flow technique. The permeability of gases except $SF_6$ in PDMS were decreased with the upstream pressure increased. $SF_6$ is much more permeable than $CF_4$, which is due to higher critical temperature of $SF_6$. The permeability decreased in the following order: $O_2$ > $N_2$ > $SF_6$ > $CF_4$. On the other hand, the permeability of gases in PEBAX followed the order: $O_2$ > $N_2$ > $CF_4$ > $SF_6$ which are opposite of the order of kinematic diameter (${\AA}$)($SF_6$ > $CF_4$ > $N_2$ > $O_2$). The $SF_6/CF_4$ pure gas selectivity in PDMS was 2.1 at 0.7 MPa.

본 연구에서는 PDMS (poly-dimethylsiloxane)와 PEBAX (polyether block amides) 분리막을 이용해 $N_2$, $O_2$, $CF_4$$SF_6$의 단일 기체 투과특성에 관하여 연구하였다. 다양한 압력으로 공급된 기체의 투과유량을 진공가압 연속흐름방식으로 측정하였으며, 이를 이용하여 투과도를 산정하였다. PDMS 분리막에서는 상부의 압력이 증가할수록 $SF_6$를 제외한 다른 기체의 투과도는 감소하였다. 또한 $SF_6$의 투과도가 $CF_4$보다 높게 나타나고 있으며 이것은 $SF_6$가 더 높은 임계온도를 가지고 있기 때문이다. PDMS 분리막에서 투과도는 $O_2$ > $N_2$ > $SF_6$ > $CF_4$ 순으로 감소하였다. 반면에 PEBAX 분리막에서 기체의 투과 경향은 $O_2$ > $N_2$ > $CF_4$ > $SF_6$ 순으로 감소하였다. 이러한 경향은 각 기체의 운동 반경의 크기(${\AA}$)($SF_6$ > $CF_4$ > $N_2$ > $O_2$) 순서와 반대로 나타났다. $SF_6/CF_4$의 순수 기체의 선택도는 PDMS 분리막에서 0.7 MPa일 때 2.1로 나타났다.

Keywords

Acknowledgement

Supported by : 정보통신산업진흥원

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