Understanding the\nSelective Removal of Perfluoroalkyl\nand Polyfluoroalkyl Substances via Fluorine–Fluorine Interactions:\nA Critical Review

As regulatory standards for per- and polyfluoroalkyl\nsubstances\n(PFAS) become increasingly stringent, innovative water treatment technologies\nare urgently demanded for effective PFAS removal. Reported sorbents\noften exhibit limited affinity for PFAS and are frequently hindered\nby competitive background substances. Recently, fluorinated sorbents\n(abbreviated as fluorosorbents) have emerged as a potent solution\nby leveraging fluorine–fluorine (F···F) interactions\nto enhance selectivity and efficiency in PFAS removal. This review\ndelves into the designs and applications of fluorosorbents, emphasizing\nhow F···F interactions improve PFAS binding affinity.\nSpecifically, the existence of F···F interactions results\nin removal efficiencies orders of magnitude higher than other counterpart\nsorbents, particularly under competitive conditions. Furthermore,\nwe provide a detailed analysis of the fundamental principles underlying\nF···F interactions and elucidate their synergistic\neffects with other sorption forces, which contribute to the enhanced\nefficacy and selectivity. Subsequently, we examine various fluorosorbents\nand their synthesis and fluorination techniques, underscore the importance\nof accurately characterizing F···F interactions through\nadvanced analytical methods, and emphasize the significance of this\ninteraction in developing selective sorbents. Finally, we discuss\nchallenges and opportunities associated with employing advanced techniques\nto guide the design of selective sorbents and advocate for further\nresearch in the development of sustainable and cost-effective treatment\ntechnologies leveraging F···F interactions.