Johanna Freilinger

Vinylimidazolium salts constitute a highly relevant class of polymerizable heterocycles, especially in the field of so-called polymer ionic liquids (PILs), and they are frequently used as components of polyelectrolytes. Therefore, crystallographic characterizations, in particular studies of charge distribution and conformational features, can provide fundamental insights concerning ion–ion and ion–dipole interactions. The structure of the title compound [1046127-79-0] has the space group symmetry P2₁/c. Its asymmetric unit contains one formula unit, consisting of two bromide anions and the halves of two cation moieties. The cation units possess inversion symmetry, and their C₆H₁₂ chains adopt an all-trans conformation.

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants, for which regulatory authorities worldwide have been compelled to impose limits in drinking water, groundwater, and surface water. This has created challenges in PFAS detection, and there is an urgent need for reliable and selective solid-phase extraction (SPE) materials for PFAS analysis. In addressing this demand, we have tailored highly crosslinked copolymers containing 3-(1H,1H,2H,2H-perfluorooctyl)-1-vinylimidazolium chloride as a comonomer with ethylene dimethacrylate in various molar ratios. For ionic fluorosurfactants, these copolymers feature a dual binding mechanism that synergistically combines fluorophilic interactions and electrostatic attraction, enhancing selectivity and binding efficiency. The adsorption behavior of short- and long-chain PFAS acids and their recoveries were evaluated and compared to those of commercial SPE cartridges. Characterization revealed the highest porosity and ion-exchange capacity (412.7±22 µeq g-1) for a monomer-to-crosslinker ratio of 2:1. Recovery experiments consistently demonstrated high PFAS recoveries (98.8%–121.6%), while PFAS enrichment studies from effluent wastewater further confirmed its robustness in complex environmental matrices (recoveries: 90.8%–99.2%). The findings underscore the potential of this innovative polyelectrolyte as a selective, regenerable, and efficient alternative to conventional SPE materials, qualifying it as a superior candidate for PFAS enrichment, detection and environmental remediation applications.