Molecularly Designed Polymer Adsorbents for Selective Recognition of Perfluorooctanoic Acid and Hydroresponsive Sustainable Regeneration.

Per- and polyfluoroalkyl substances (PFAS) represent a global environmental threat due to their chemical stability and bioaccumulation. However, the efficacy of current adsorbents in contaminated source remediation is constrained by limited selectivity and the lack of sustainable regenerability. Here we report AR-1, a pore-size-tuned cross-linked polymethacrylate adsorbent for perfluorooctanoic acid (PFOA) capture and water-mediated regeneration. By engineering high-density ester-functionalized amphiphilic microenvironments within nanoconfined channels, AR-1 relies on engineered mesoporous confinement, hydrogen bonding, local polar contacts, and hydrophobic/fluorocarbon-chain partitioning interactions. These interactions enable selective molecular recognition of PFOA and promote its confined self-assembly into stable intrapore aggregates. Consequently, AR-1 yields a PFOA adsorption capacity of 531.8 mg g-1 and a removal efficiency of >99% in industrial wastewater. It maintains high selectivity for PFOA even in the presence of a 10,000-fold excess of competing background ions. Furthermore, pH-responsive modulation of interfacial binding affinity allows for nearly 100% regeneration using water alone. This strategy offers a sustainable, high-performance solution to the critical challenge of PFAS contamination.