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 modifica-tion reaction—for the first time, applicable to commercial resins—that enables the incorporation of a tunable fluorous effect. We synthesized 20 modified resins with varying degrees of fluorous affinity, allowing systematic evaluation of how F-F interaction impacted ultrashort and short chain PFAS removal. Successful modification was confirmed through multi-ple characterization techniques. Notably, modified resin, OC-C4-0.5, demonstrated exceptional trifluoroacetic acid (TFA) retention, with less than 2% capacity loss over 72 h, far outperforming the pristine resin (15% loss). Both OC-C2-0.5 and OC-C4-0.5 also showed a substantially higher TFA uptake in thermodynamic studies, achieving 26% and 28% more removal, respectively, compared to OC Unmod during adsorption thermodynamics studies. This work establishes a foundation for systematically investigating the fluorous effect’s role in PFAS sorption, particularly for ultrashort and short chain species. It also highlights the potential of fluorous-driven strategies to characterize and manage these challenging compounds.