Fluorous Modification of Commercial Resins for Ultrashort and Short Chain PFAS Removal

Ultrashort and short chain per- and polyfluoroalkyl substances (PFAS) represent an emerging class of micropollutants that extend beyond the well-studied and regulated legacy PFAS. These compounds present unique sorptive removal challenges due to their weaker hydrophobic interactions with conventional sorbents and their pronounced ionic character in natural water matrices, where they are easily outcompeted by more prevalent inorganic ions. Here, we introduce a novel modification reaction─for the first time, applicable to commercial resins─that enables the incorporation of a tunable fluorous effect. We synthesized 20 modified resins varying in fluorous affinity, allowing a systematic evaluation of how the F···F interaction impacted ultrashort and short chain PFAS removal. Successful modification was confirmed through multiple characterization techniques. Notably, modified resin, OC-C4-0.5, demonstrated enhanced trifluoroacetic acid (TFA) retention with less than 2% capacity loss over 72 h, outperforming the pristine resin (15% loss). This same modified resin showed higher TFA capture capacity compared to pristine OC Unmod. This work establishes a foundation for systematically investigating the fluorous effect’s role in PFAS sorption, particularly for ultrashort and short chain species, and suggests that fluorous-driven strategies hold promise for the characterization and management of challenging compounds though further studies are needed to delineate their optimal application.