Elucidating the role of ionic liquids in polymer composites

Addressing the escalating challenge of climate change requires advanced CO2 capture solutions; we developed spirobisindane-modified polyamide ionene membranes featuring intrinsic nanoporous architecture, high CO2 permeability and selectivity, and hydrogen bond–driven self-healing. Molecular dynamics simulations, small-angle X-ray scattering, and tensile testing quantified how adding the ionic liquid 1-benzyl-3-methylimidazolium bistriflimide ([BMIM+][TF2N−]) affects performance. The ionic liquid fills spirobisindane-created pores—reducing free volume without altering polymer conformation—softens the matrix, strengthens ionic interactions, and accelerates damage recovery. An optimal loading of 0.5 IL per monomer maximized recovery of Young’s modulus and tensile strength, minimizing membrane degradation and lowering carbon capture maintenance costs.