Intrinsic microporosity polymers (tb-pims) membrane of new generation: Molecular modelling and permeation properties

PIMs are a class of ultra-permeable microporous polymer that are attracting attention for membrane applications [1]. A novel member of this family is TB-PIM (Fig. 1). The choice of diamine monomer needs to conform to the design concept of PIMs to provide highly rigid and contorted structures, although the V-shaped bicyclic TB unit also introduces contortion in addition to providing strongly basic functionality. Several aromatic diamine monomers have been investigated as precursors and found to yield highly microporous polymers of sufficiently high molecular mass for film formation. Modelling of transport of individual penetrant molecules has provided a deeper understanding of the correlations between transport and structural features of the polymeric membrane materials [2]. Based on a given chemical architecture, a novel synthetic polymer can theoretically be developed and scrutinized for its utility as a separation medium. This concept offers enormous potential for development in the material sciences. This fact, coupled with increasing computational power and efficiency, allows macromolecular design to be brought to a wider range of users. However, there are still some challenges that must be overcome in the use of molecular simulation as a tool for membrane design. Accurate and robust forcefield development, and preparation of "correct" packing models are challenges that are currently being addressed.