Gas-separation membranes loaded with porous aromatic frameworks that improve with age

Cher Hon Lau, Kristina Konstas, Aaron W. Thornton, Amelia C. Y. Liu, Stephen Mudie, Danielle F. Kennedy, Shaun C. Howard, Anita J. Hill, Matthew R. Hill

Research output: Contribution to journalArticleResearchpeer-review

106 Citations (Scopus)

Abstract

Porosity loss, also known as physical aging, in glassy polymers hampers their long term use in gas separations. Unprecedented interactions of porous aromatic frameworks (PAFs) with these polymers offer the potential to control and exploit physical aging for drastically enhanced separation efficiency. PAF-1 is used in the archetypal polymer of intrinsic microporosity (PIM), PIM-1, to achieve three significant outcomes. 1) hydrogen permeability is drastically enhanced by 375% to 5500 Barrer. 2) Physical aging is controlled causing the selectivity for H2 over N2 to increase from 4.5 to 13 over 400 days of aging. 3) The improvement with age of the membrane is exploited to recover up to 98% of H2 from gas mixtures with N2. This process is critical for the use of ammonia as a H2 storage medium. The tethering of polymer side chains within PAF-1 pores is responsible for maintaining H2 transport pathways, whilst the larger N2 pathways gradually collapse.

Original languageEnglish
Pages (from-to)2669-2673
Number of pages5
JournalAngewandte Chemie - International Edition
Volume54
Issue number9
DOIs
Publication statusPublished - 23 Feb 2015

Keywords

  • Gas separation
  • Membranes
  • Physical aging
  • Polymers
  • Porous aromatic frameworks

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