Hybrid Magnetic Polymerica Nanoparticles for the Environmental Remediation of Crude Oil and Perfluorooctanoic Acid from Aqueous Systems

Abstract

Environmental remediation of pollutants from water systems is an expanding billion dollar industry. Recently, engineered nanoparticles (ENPs) have been of particular interest to this field as they hold promise in improving existing remediation technologies. Hybrid well-defined magnetic shell crosslinked knedel-like (MSCK) nanoparticles comprised of iron oxide nanoparticles encapsulated in amphiphilic block copolymer micellar assemblies and selectively crosslinked throughout the hydrophilic shell domain of the assembly have been investigated for their pollutant uptake capabilities. The main focus of this dissertation is to design, develop, and investigate tailored MSCK nanoparticle systems for specific environmental pollutants and applications.

Alterations of the polymeric components of the nanoparticle systems allow for the development of fine-tuned materials by providing control over the composition, shape, and size of the nanoparticles produced. The polymeric components utilized for the co-assemblies of the MSCK systems presented here were produced through two types of controlled living radical polymerizations, atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain-transfer (RAFT) polymerization. The non-covalent incorporation of iron oxide nanoparticles into the cores of the systems was performed in order to afford magnetically active materials that can be controlled and/or recovered after deployment through the use of an external magnetic field. In order to achieve a high magnetic response, the co-assemblies of these systems were achieved with equal mass feed ratios of the polymers and iron oxide nanoparticles during the micellization process. MSCKs designed for their utilization following the bulk recovery stage at oil spill sites to recover oil at low concentrations, or sheen, were composed of poly(acrylic acid)20-b-polystyrene280 (PAA20-b-PS280) and demonstrated superb sheen recovery of ten-fold by weight. Fluorinated MSCK (MSCK-F9) nanoparticles were also investigated for the remediation of perfluorooctanoic acid (PFAO) from water. A library of four fluorinated systems was developed in order to probe the effect size/fluorine content and shell charge would have on the recovery efficiency of these materials. A fluorinated monomer was incorporated into the polymer during polymerization in order to increase the solvation of PFOA within the core during loading. The results of this dissertation suggest that MSCKs are a viable option and ENPs for environmental remediation.