Recent progress in PIM-1 based membranes for sustainable CO2 separations: Polymer structure manipulation and mixed matrix membrane design

Greenhouse gas separation, storage, and utilization are extremely urgent due to the growing climate problems and resource shortages. Polymer-based membrane separation as one of the most promising technologies for large-scale and high-efficient gas separation has been studied extensively for decades in virtue of its low-cost and energy saving process. The emergence of ultra-permeable polymers of intrinsic microporosity (PIMs), particularly the PIM-1 with excellent solubility in common solvents, has attracted a lot of research interest towards next generation high-performance membrane fabrication for CO2 separations. However, despite the high gas permeability and excellent workability, PIM-1 exhibits relative low gas selectivity and suffers from significant physical aging, therefore the research focused on improving the permselectivity and long-term stability of PIM-1 based membranes has been developed rapidly in recent years. Given that, the latest progress of modification strategies for PIM-1 based membranes are summarized in two perspectives: design and modification of PIM-1 intrinsic structure and fabrication of PIM-1/nanofiller mixed matrix membranes, especially for CO2 separations. Furthermore, the advantages and limitations of existing researches are discussed, and the feasible future research directions are boldly prospected, hoping to be instructive for developing PIM-1 based high-performance membranes for crucial gas separations like CO2 capture, H2 purification and natural gas purification.