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 journalArticle

20 Citations (Scopus)

Abstract

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
Volume475
DOIs
Publication statusPublished - 2015 Feb 1

    Fingerprint

Keywords

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

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Materials Science(all)
  • Biochemistry
  • Filtration and Separation

Cite this

Kang, W. R., Lee, A. S., Park, S., Park, S. H., Baek, K. Y., Lee, K. B., Lee, S-H., Lee, J., Hwang, S. S., & Lee, J. S. (2015). Free-standing, polysilsesquioxane-based inorganic/organic hybrid membranes for gas separations. Journal of Membrane Science, 475, 384-394. https://doi.org/10.1016/j.memsci.2014.10.024