Fluorinated Hydrogels for Remediation of Per- and Polyfluoroalkyl Substances from Water

Contaminated water is a growing issue as our world only industrializes more. Some common man-made contaminants are per- and polyfluoroalkyl substances (PFAS), otherwise known as “forever chemicals”. These chemicals are commonly used as stain resistant or waterproof agents because of their hydrophobicity and extremely strong intramolecular forces due to their many carbon-fluorine bonds. The strength of the bonds within PFAS cause them to not break down naturally, leading to their accumulation in the environment (e.g., water sources) and human exposure and potential health consequences. One approach to this issue is to use hydrogels to absorb PFAS from contaminated water. Hydrogels are crosslinked, hydrophilic polymers that can be functionalized for targeted contaminant removal from water. We studied the use of fluorinated hydrogels to sorb PFAS from contaminated water. Fluorinated hydrogels will attract PFAS through fluorous interactions. Hydrogels were synthesized using free radical polymerization. Comonomers 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate (DDFHA) and acrylamide (Aam), cross-linker N,N’-methylenebisacrylamide (NNMBA), catalyst tetraethylmethyl-ethyldiamine (TEMED), and initiator ammonium persulfate (APS) were used for the hydrogel synthesis. Swelling studies were conducted on hydrogels of varying DDFHA composition to confirm the DDFHA incorporation in the hydrogel. It was found that increasing DDFHA composition led to less swelling of water by the hydrogels. Binding studies of select PFAS compounds were conducted in water over 24 hours. A significant amount of PFAS was found bound to the hydrogels. These findings point toward a promising solution for remediation of PFAS-contaminated water.