Scientific Seminar / Webinar - By Prof Peter M. Budd

A Polymer of Intrinsic Microporosity (PIM) is a polymer that acts as a molecular sieve as a consequence of its backbone structure, which is randomly twisted due to “sites of contortion” such as spiro-centres, but which cannot undergo large-scale conformational change because there are no single bonds about which rotation can occur. PIMs have been investigated for a variety of membrane separation processes, including gas separation, organophilic pervaporation and organic solvent nanofiltration. For gas separation, early PIMs helped to define Robeson’s 2008 upper bound of performance for key gas pairs, and recent research on PIMs has led to significant advances in the upper bounds.

Many approaches are utilized to tailor materials for particular separations and to improve long-term membrane stability. These approaches include the synthesis of novel monomers, the chemical, thermal or ultraviolet treatment of precursor polymers, and the incorporation of various types of filler to form mixed matrix membranes. Current research is extending these concepts to very thin active layers in thin film composite (TFC) membranes that are viable for commercial application.