Effect of oxygen atoms and cyano groups on mixed gas separation of PIM-1 membranes: MD simulations

The polymer of intrinsic microporosity PIM-1 shows a unique structure prevented intra-chain and inter-chain aggregation and produces high porosity and the possibility of functionalization, it is considered as a promising candidate for applications in the field of gas separation. In this work, PIM-1 membranes were constructed with 21-step method via molecular dynamics (MD) simulations, the structure information of PIM-1 membrane and their separation performances on CO2/N2 mixture was explored. The influence of functional groups on adsorption and permeation behavior of CO2/N2 mixture was explored, the transport mechanism and separation mechanism were also illustrated. The simulation results revealed that the permeation behavior of CO2/N2 mixture through PIM-1 membrane is a solubility-dominated separation mechanism, and the cyano group in PIM-1 chain and terminal hydroxyl groups play an important role in the gas adsorption and permeation process. Overall, this study provides valuable insights for the design and preparation of high-performance membrane materials.