Free-standing, polysilsesquioxane-based inorganic/organic hybrid membranes for gas separations

Woo Ram Kang, Albert S. Lee, Sunghwan Park, Sang Hee Park, Kyung Youl Baek, Ki Bong Lee, Sang Hyup Lee, Jung Hyun Lee, Seung Sang Hwang, Jong Suk Lee

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)


Polysilsesquioxanes (PSSQs) are composite materials consisting of inorganic framework and organic functional groups. Their inherent dual characteristics offer various applications including microelectronics, optics and biosciences. For the first time, free standing ladder-like PSSQ films were successfully prepared for gas separations, allowing practical applications in the membrane area. In order to fabricate a free-standing PSSQ film, a novel ladder-like poly(phenyl-co-glycidoxypropyl) silsesquioxanes with phenyl:glycidoxypropyl copolymer ratio of 6:4 (LPG64) were synthesized by a base-catalyzed sol-gel reaction. Moreover, the LPG64 films were thermally crosslinked with octa(aminophenyl)-T8-silsesquioxane (OAPS) with different concentrations of OAPS. Single gas (i.e. He, H2, CO2, O2, N2, and CH4) transport measurements were performed for the LPG64 as well as LPG64/OAPS composite membranes. The LPG64 membrane exhibited a relatively high CO2 permeability of 47.88Barrer compared to other gases with CO2/N2 permselectivity of 30.5. The annealing effect on the transport results of the LPG64 membrane was negligible due to its rigid inorganic framework. Combination of our transport analysis and XRD characterization demonstrated that the addition of OAPS led to more dense chain packing, reducing permeability for all the gases tested in this work with increase in permselectivities. Especially, the LPG64/OAPS (80/20wt/wt) membrane improved He/N2 and H2/N2 permselectivities by 98% and 80%, respectively, compared to those for neat LPG64 membranes.

Original languageEnglish
Pages (from-to)384-394
Number of pages11
JournalJournal of Membrane Science
Publication statusPublished - 2015 Feb 1

Bibliographical note

Funding Information:
This work was supported by the Korea CCS R&D Center (KCRC) (No. 2014M1A8A1049315) and the Global Excellent Technology Innovation of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) (No. 20135010100750 ) under the Ministry of Trade, Industry & Energy, Republic of Korea.

Publisher Copyright:
© 2014 Elsevier B.V.

Copyright 2020 Elsevier B.V., All rights reserved.


  • Crosslinking
  • Free-standing composite membranes
  • Gas separations
  • Ladder-like polysilsesquioxane

ASJC Scopus subject areas

  • Biochemistry
  • General Materials Science
  • Physical and Theoretical Chemistry
  • Filtration and Separation


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