Highly efficient and removal of per- and polyfluoroalkyl substances from water using fluorinated porous polymer network-based adsorbents

ABSTRACT In this study, a fluorinated porous polymer network-based adsorbent, denoted as PS-PPN-F, was successfully synthesized through atom transfer radical polymerization (ATRP) and subsequent fluorinated amine functionalization for efficient adsorption of PFAS from aqueous environments. The incorporation of porous polymer networks significantly increased the surface area of polystyrene microspheres from approximately 110 to 1290 m² g⁻¹, while fluorinated functionalization introduced strong fluorophilic affinity toward PFAS molecules. The maximum adsorption capacities obtained from the Langmuir model reached 588.24 mg g⁻¹ for PFOA and 303.03 mg g⁻¹ for short-chain PFA, which were substantially higher than those of unmodified PS-PPN. PS-PPN-F also exhibited remarkable selectivity toward fluorinated contaminants, achieving removal efficiencies above 95% for PFOA and PFOS, while maintaining minimal adsorption toward non-fluorinated analogues and humic acid. Density functional theory (DFT) calculations and electrostatic potential (ESP) mapping further revealed that fluorinated domains and amino groups on PS-PPN-F provided energetically favorable adsorption sites for PFAS molecules. Negative binding energies ranging from −4.31 to −10.62 kcal mol⁻¹ confirmed spontaneous adsorption driven by synergistic fluorophilic, hydrophobic, and electrostatic interactions. In addition, the adsorbent exhibited excellent regeneration ability, maintaining high adsorption performance over multiple adsorption–desorption cycles using 70% methanol solution at pH 9. These results demonstrate that PS-PPN-F is a highly efficient and reusable adsorbent with strong potential for selective PFAS remediation in complex environmental water systems.