Fluoroolefin-vinyl ether copolymer ionic fluorogels for PFAS remediation from water

Area of Science:

• Environmental Chemistry
• Polymer Science
• Materials Science

Background:

• Per- and polyfluoroalkyl substances (PFAS) are persistent, toxic environmental contaminants found globally in water sources.
• Increasing regulatory limits on PFAS in drinking water necessitate advanced removal technologies.
• Existing sorbents often lack the required selectivity and regenerability for effective PFAS remediation.

Purpose of the Study:

• To develop novel granular sorbents for selective and regenerable removal of PFAS from water.
• To investigate the structure-property relationships of a new class of Ionic Fluorogels (IFs) based on fluoroolefin-vinyl ether (FVE) copolymers.
• To evaluate the performance of FVE-based IFs for PFAS binding capacity, regeneration, and selectivity.

Main Methods:

• Synthesis of a library of FVE-based copolymers with varying fluoroolefin monomers and multivalent amines.
• Functionalization of copolymers to create cationic ion exchange resins (Ionic Fluorogels).
• Performance testing of IFs for PFAS sorption capacity (e.g., GenX), regeneration efficiency, and selectivity against commercial resins using simulated and natural waters.

Main Results:

• FVE-based IFs exhibit high binding capacity for GenX (up to 770 mg/g).
• The sorbents demonstrate facile regeneration with consistent performance over five cycles.
• IFs show enhanced PFAS selectivity compared to commercial ion exchange resins in various water matrices.
• A synergistic effect between the fluorophilic matrix and cationic charge enhances PFAS sorption.

Conclusions:

• Ionic Fluorogels based on FVE copolymers represent a promising new class of materials for PFAS remediation.
• The design, incorporating a fluorophilic matrix and specific cationic charge ratios, is crucial for high-performance PFAS removal.
• These novel sorbents offer a viable solution for meeting stringent drinking water regulations concerning PFAS contamination.