Polymers of Intrinsic Microporosity (PIMs): High Free Volume Polymers for Energy-Efficient Separations
12:00 - 12:30
Level 0, between bld. 4 and 5
Polymers of intrinsic microporosity (PIMs) are glassy polymers which possess high free volume and high internal surface area as a consequence of their relatively rigid, contorted macromolecular backbones. They comprise fused ring sequences interrupted by spiro-centres or other sites of contortion. PIMs have a high affinity for gases such as carbon dioxide, and for small organic species. The first commercial application of a PIM is in a sensor developed by 3M that acts as an end-of-life indicator for organic vapour adsorbing cartridges. PIMs are being investigated as membrane materials and adsorbents for a variety of industrial separation processes, including gas separations (e.g., carbon dioxide capture) and organophilic liquid separations (e.g., bioalcohol recovery). For membrane gas separation, PIMs contributed to the revision of the upper bounds of performance by Robeson in 2008.
In recent years there has been significant research on PIM membranes aimed at tailoring selectivity, enhancing permeability and improving the long-term performance. This includes (1) new polymer synthesis, (2) chemical post-modification of precursor polymers, (3) thermal or ultraviolet treatment of membranes, (4) formation of polymer blends and (5) the addition of inorganic materials, carbons (activated carbons, nanotubes, graphene), metal-organic frameworks or purely organic materials, to form mixed matrix membranes.