Abstract
High free-volume copolymers were prepared via polycondensation with 2,3,5,6,-tetrafluoroterephthalonitrile (TFTPN) in which a portion of the 3,3,3',3'-tetramethyl-1,1'-spirobisindane (TTSBI) of PIM-1 was replaced with dibutyl anthracene maleimide (4bIII). An investigation of free volume using positron annihilation lifetime spectroscopy (PALS), and gas permeation measurements was carried out for the thin film composite copolymer membranes and compared to PIM-1. The average free volume hole size and the gas permeance of the copolymer membranes increased with decreasing TTSBI content in the copolymer.
Highlights
Membrane-based gas separation has attracted great interest in the industrial context due to its advantages over conventional separation methods
To fully understand the properties of the copolymers, we investigated the free volume behavior of these copolymers using positron annihilation lifetime spectroscopy (PALS) to clearly correlate the increase in permeability with the change in free volume and average hole size
Various copolymers were synthesized in which a portion of the spiro unit (TTSBI) of polymers of intrinsic microporosity (PIMs)-1 was replaced by antharcene maleimide-based comonomers (4bIII)
Summary
Membrane-based gas separation has attracted great interest in the industrial context due to its advantages over conventional separation methods. Only a few polymeric materials are used for industrial membrane-based separations, a diverse number of materials have been reported for different gas separation pairs (e.g., O2/N2, CO2/N2, CO2/CH4) [2,3,4,5,6,7,8,9,10]. There exists a trade-off between gas permeability and selectivity; this means highly permeable polymer membranes always display poor selectivity and vice versa. This trade-off has been described by the Robeson upper-bound relationship, which has been considered an empirical criterion for judging the broad spectrum of membranes [11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
