Hydrolytically Stable Ionic Fluorogels for High-Performance Remediation of Per- and Polyfluoroalkyl Substances (PFAS) from Natural Water.

PFAS are known bioaccumulative and persistent chemicals which pollute natural waters globally. There exists a lack of granular sorbents to efficiently remove both legacy and emerging PFAS at environmentally relevant concentrations. Herein, we report a class of polymer networks with a synergistic combination of ionic and fluorous components that serve as granular materials for the removal of anionic PFAS from water. A library of Ionic Fluorogels (IFs) with systematic variation in charge density and polymer network architecture was synthesized from hydrolytically stable fluorous building blocks. The IFs were demonstrated as effective sorbents for the removal of 21 legacy and emerging PFAS from a natural water and were regenerable over multiple cycles of reuse. Comparison of one IF to a commercial ion exchange resin in mini-rapid small-scale column tests demonstrated superior performance for the removal of short-chain PFAS from natural water under operationally relevant conditions.

C-H Functionalization of Commodity Polymers.

Synthetic manipulation of polymer substrates is one of the oldest and most reliable methods to increase the functional diversity of soft materials. Modifying the chemical structure of polymers that are already produced on a commodity scale leverages the current high-volume and low-cost production of commodity plastics for the discovery of modern materials. A myriad of polymer C-H functionalization methods have been developed which enable the modification of material properties on both a laboratory and industrial scale. More recently, driven by advances in C-H activation, photoredox catalysis, and radical chemistry, chemoselective approaches have emerged as a means to impart precise functionality onto commodity polymer substrates. This Review discusses the historical significance of and contemporary advances in the C-H functionalization of commodity polymers. The conceptual approach outlined herein presents exciting new directions for the field, including increasing the value of otherwise pervasive materials, uncovering entirely new material properties, and a viable path to upcycle post-consumer plastic waste.

Ionic Fluorogels for Remediation of Per- and Polyfluorinated Alkyl Substances from Water.

Per- and polyfluorinated alkyl substances (PFASs) contaminate groundwater, surface water, and finished drinking water internationally. Their ecological persistence and adverse human health effects demand effective remediation approaches. Motivated by the limitations in selectivity and performance of current PFAS removal technologies, we report a platform approach for the development of ionic fluorogel resins that effectively remove a chemically diverse mixture of PFAS from water. The synthesis of a material library with systematic variation in fluorous and ionic components led to the identification of a resin that demonstrated rapid removal of PFASs with high affinity and selectivity in the presence of nonfluorous contaminants commonly found in groundwater. The material can be regenerated and reused multiple times. We demonstrate ionic fluorogels as effective adsorbents for the removal of 21 legacy and emerging PFASs from settled water collected at the Sweeney Water Treatment Plant in Wilmington, North Carolina.