Understanding the Topology of the Polymer of Intrinsic Microporosity PIM-1: Cyclics, Tadpoles, and Network Structures and Their Impact on Membrane Performance

Andrew B. Foster, Marzieh Tamaddondar, Jose M. Luque-Alled, Wayne J. Harrison, Ze Li, Patricia Gorgojo, Peter M. Budd

Research output: Contribution to journalArticlepeer-review

57 Scopus citations


The synthesis of PIM-1 is reported from step-growth polymerizations of 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane with the commercially cheaper monomer, tetrachloroterephthalonitrile. Nitrogen-purged polymerizations (100-160 °C) were quenched after a monitored increase in viscosity. A combination of multiple detector size exclusion chromatography, nuclear magnetic resonance, matrix-assisted laser desorption/ionization-time of flight (MALDI TOF) mass spectrometry, dynamic light scattering, and elemental analysis was used to elucidate significant structural differences (cyclic, branched, tadpole, extended, and network topologies) in the polymers produced under different conditions. A significant proportion of the apparent surface area (up to 200 m2 g-1) associated with PIM-1 can be attributable to whether its contorted polymer chains in fact link to form cyclic or other nonlinear structures. Membranes cast from solutions of polymer samples containing higher branching and network contents exhibited higher gas pair selectivities (CO2/CH4 and CO2/N2), above the Robeson 2008 upper bound. A toolbox approach to the characterization and production of topologically different PIM-1 samples has been developed which can be used to tune membrane performance for gas separation and other applications.
Original languageEnglish (US)
Pages (from-to)569-583
Number of pages15
Issue number2
StatePublished - Jan 7 2020
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2022-06-14
Acknowledgements: P.M.B., M.T., and A.B.F. would like to acknowledge the support of Programme Grant EP/M01486X/1 (SynFabFun) and W. J. H. the support of Grant EP/K016946/1 (Graphene-based membranes) funded by the Engineering and Physical Sciences Research Council (EPSRC). We thank Emma Enston, Anne Davies, and Martin Jennings for their assistance in obtaining the MALDI TOF mass spectra and elemental analysis measurements. We thank Prof. Ingo Pinnau (King Abdullah University of Science and Technology, Saudi Arabia) for kindly providing the porous PAN membrane (Sepro PA350 ultrafiltration membrane) used in preparation of thin films.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.

ASJC Scopus subject areas

  • Materials Chemistry
  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry


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