Modulating Multiple Interactions in Poly(ionic Liquid)s for Efficient Removal of Per- and Polyfluoroalkyl Substances

Poly(ionic liquid)s (PILs) are versatile materials with wide-ranging applications, yet the use of porous PILs for adsorbing perfluoroalkyl and polyfluoroalkyl substances (PFASs) has been scarcely reported. Herein, we report a series of imidazolium-based mesoporous PILs for the removal of PFASs through multiple interaction mechanisms. Among them, PDB-F, synthesized via free-radical copolymerization of divinylbenzene (DVB) and 3-(4,4,4-trifluorobutyl)-1-vinyl-1H-3-imidazolium bromide (F-VBIm) at a 1:1 mol ratio, exhibited an exceptional adsorption capacity (2471.7 mg/g at 25 °C) for perfluorooctanoic acid (PFOA), ranking it among the most effective polymer-based adsorbents to date. Comprehensive structural characterization and performance studies revealed that the outstanding PFASs adsorption by PDB-F arises from the synergistic effects of electrostatic, hydrophobic, pore filling, and fluorophilic (F–F) interactions. Moreover, PDB-F demonstrated high efficacy in removing trace-level PFOA across different water matrices along with versatility for several common PFASs. Besides, PDB-F displayed good regeneration and remarkable reusability. This work offers valuable insights into the role of synergistic interactions in PFASs adsorption and lays the foundation for the rational design of high-performance adsorbents in the future.