(359d) Magnetic Nanocomposite Microparticles for On/Off Binding of Persistent Organic Pollutants

Magnetic nanocomposite microparticles (MNMs) were produced using iron oxide nanoparticles incorporated into a polyphenolic-based polymer matrix with high affinity for organic pollutants. This platform allows for the specific binding of chlorinated organics, the rapid magnetic separation of bound organics from contaminated water sources, and the thermal destabilization of the polymer matrix for contaminant release and material regeneration. Quercetin multiacrylate (QMA), an acrylated form of the nutrient polyphenol with known affinity for chlorinated organics, was crosslinked with polyethylene glycol (PEG) diacrylate using a free radical polymerization in the presence of magnetic iron nanoparticles, and the magnetic nanocomposite was subsequently cryomilled to form the MNMs. Particles were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA). Pollutant binding studies were performed using model chlorinated organic pollutants, polychlorinated biphenyls (PCBs, specifically PCB 126), to determine binding affinity and capacity, as well as optimal binding kinetics, and this was quantified using LC-MS/MS. It was demonstrated that the MNMs effectively bound PCBs with the addition of QMA resulting in greater affinity. An alternating magnetic field (AMF) was used to heat and destabilize the binding in the polymer matrix leading to PCB release from the particles, and the percentage of uptake and release was determined.  Repeated PCB binding/release was performed to determine MNM stability and reusability.