Fluorinated Hypercrosslinked Polymers with Exceptional Capacity for Perfluorooctanoic Acid Removal from Water

Abstract

Perfluorooctanoic acid (PFOA) is a persistent emerging pollutant that has raised significant environmental and health concerns due to its toxicity, bioaccumulation, and resistance to degradation. The effective removal of PFOA from aqueous systems necessitates the development of advanced adsorbent materials with superior efficiency and capacity. We report the synthesis and characterization of fluorinated hypercrosslinked polymers (FHCPs), which exhibit exceptional adsorption of PFOA from water, including tap and lake samples. Among these, FHCP-3 achieved an outstanding equilibrium adsorption capacity of 1550 ± 60 mg g−1 for PFOA and demonstrated impressive kinetics, reaching equilibrium within 60 min even at low pollutant concentrations (1 mg L−1). Notably, FHCP-3 also displayed facile regeneration and reusability, retaining almost quantitative removal efficiency over six consecutive adsorption–desorption cycles. Density functional theory calculations, including binding energy, Gibbs free energy, and reduced density gradient analysis, further revealed the strong non-covalent interactions driving selective PFOA adsorption. This work highlights FHCP-3 as a high-performing adsorbent that surpasses many state-of-the-art materials in PFOA adsorption capacity, kinetics, and durability while offering a simple, low-cost synthesis. These findings position FHCP-3 as a promising platform for the rapid and efficient removal of PFOA, addressing critical challenges in water purification and environmental remediation.