Tuning Block Polymer Design to Enable for PFAS Remediation

Perfluorinated alkyl substances (PFAS) pose a significant threat to water supplies due to their high toxicity and robust stability. Current remediation methods are typically limited by their cost, their ability to only capture or decompose the PFAS compounds, the volume of water they can treat, and the time required to process said volume. Here, we demonstrate a new type of material composed of an organic membrane functionalized with β-cyclodextrin moieties and doped with electrochemical oxidative catalyst (i.e. a composite based upon Ti₄O₇ and carbon nanotubes) to be capable of providing in-place, high-throughput degradation of PFAS. This is accomplished through the hydroxyl radicals produced by the electrocatalyst and PFAS high affinity to β-cyclodextrin, and the utilization of the surface-segregation and vapor-induced phase separation (SVIPS) casting technique which induces dense pore distributions across the membrane in conjunction with high analyte capacity due to the self-assembly of functional groups on the pore walls and increased surface area that arises from the nanostructured morphology. This lacey nanostructure thus shifts the mode of PFAS adsorption to the β-cyclodextrin from usually being diffusion controlled to a faster convective mass transport.