(558f) Magnetic Nanocomposites: Synthesis, Characterization and Application for Environmental Remediation

Magnetic nanocomposites can provide unique solutions to environmental problems. Magnetic nanoparticles (MNPs) embedded in nanocomposite enable energy to be delivered remotely to the material using an alternating magnetic field (AMF). This localized energy can be used to drive processes to enhance material performance, including disruption of binding interactions, increased reactivity etc. Here, we will highlight the synthesis and characterization of different magnetic nanocomposites and their applications with AMF to sorb/desorb contaminant and degrade contaminants through enhanced reactivity. Decades of use of organic and halogenated chemicals in product manufacturing and commercial applications has led to environmental contamination and connected to detrimental health impacts. To address the need to remove these from the environment and prevent human exposures, we have synthesized and characterized a magnetic nanocomposite hydrogel loaded with iron oxide MNPs via free radical polymerization for the AMF activation of sulfate radicals from sodium persulfate and removal of a model organic contaminant rhodamine B (RhB). We found approximately 100% of RhB was removed within 20 min using these magnetic nanocomposites. This removal was attributed primarily to the activation of sulfate radicals, triggered by the localized heating of the MNPs under AMF exposure. In another application hydrogel loaded with iron oxide nanoparticles and fluorinated hydrogel loaded with iron oxide nanoparticle were synthesized via free radical polymerization for the reversible capture of halogenated contaminants such as perfluoroalkyl substances (PFAS), with regeneration of the nanocomposite driven by AMF exposure. More than 90% PFAS was removed by cationic magnetic nanocomposites and promising amounts of magnetic composite was regenerated through AMF exposure.