Per- and poly-fluoroalkyl species (PFAS) are manufactured chemicals that have become widespread contaminants in drinking water. Physical adsorption techniques have been implemented on large scale for PFAS removal, however, these techniques are limited by their high cost and low effectiveness. In this study, an aluminum oxide hydroxide membrane was functionalized with a novel amphiphilic coating and evaluated under dynamic and gravity filtration conditions for PFAS removal. Under dynamic conditions, we observed &gt;99% removal of eleven of eighteen PFAS as defined in EPA537.1. Gravity filtration conditions produced similar results with &gt;90% removal of fifteen of the eighteen PFAS. The PFOA and PFOS breakthrough rates of the amphiphilic silanes were compared to granular activated carbon, the commonly used filtration technology. Filters functionalized with the new amphiphilic coating outperformed granular activated carbon by 30 to 80 times for the PFOA adsorption capacity and even greater for PFOS under dynamic filtration conditions. We used enhanced-sampling molecular dynamics simulations to compute the free energy, enthalpy, and entropy of interactions between coating molecules and six PFAS contaminants. Overall, the computed interaction free-energy values agree with experimental filtration performance across contaminants. This indicates the potential for future in-silico rational design of new PFAS ligands using simulated free-energy values to predict filtration efficiency to further reduce cost and development time.

Removing forever chemicals via amphiphilic functionalized membranes

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