Development and Characterization of Synthetic and Biohybrid Hydrogel Enterosorbents for Removal of PFAS through the GI Tract

PFAS (per- and polyfluoroalkyl substances) are a class of chemicals developed for various applications, but they typically do not break down in the environment for thousands of years making them nearly permanent fixtures once they are manufactured. In recent years, some PFAS have been found to cause adverse health effects, and thus, there exists a need to remove these chemicals from the human body to decrease the body burden of PFAS and prevent chronic diseases. Enterosorbents offer a non-invasive and promising future for the removal of these substances from the GI tract. In this research, poly(acrylamide) based hydrogels and hydrogel composites with the cationic co-monomers acrylamidopropyltrimethyl-ammonium chloride (DMAPA-Q) and diallyldimethylammonium chloride (DADMAC), the natural polymer gelatin, and the particulate calcium montmorillonite clay, were synthesized and characterized for their ability to perform as an enterosorbent. Synthesis was conducted via free radical polymerization and several characterization techniques were used including Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and ultraviolet-visible spectroscopy (UV-vis) to determine material properties. The aim of this study was to confirm that these hydrogels could be synthesized and their cationic functionality persists through the polymerization, quantify the swelling capacity, and test their affinity for PFAS using model dye compounds. Successful synthesis of (poly)acrylamide hydrogels and hydrogel composites with cationic co-monomers DADMAC or DMAPA-Q or the gelatin with varying clay concentration was confirmed using FTIR and TGA, respectively. The sorption studies confirmed that cationic systems have high ability to remove model PFAS compounds from water. These results are promising for enterosorbent applications.