Efficient Polymeric Solutions for Oil Spill Remediation
Creators: Damavandi, Fereshte
Publisher: name: University of Alberta Library
Year: 2023

<p>Oil spills are a worldwide concern that threaten the environment, ecosystems, human health, and economy. Conventional methods to combat oil spills, such as in-situ burning, booms and skimmers, dispersants, and biodegradation are not effective enough. A more efficient technology is needed to contain future oil spill incidents. For example, the lack of efficient oil spill responses in the BP (British Petroleum) spill in the Gulf of Mexico caused massive, short- and long-term environmental and industrial damages that could have been minimized with better methods were available at the time. Oil solidifiers, a new class of clean-up technology, have been recently introduced for practical and efficient remediation of oil spills. In this thesis, I developed two different types of oil spill solidifiers: a magnetic polymer nanocomposite and a polymer organogelator. I investigated the oil removal of these two solidifiers by removing high and low viscosity oil from the water surface. I also evaluated the effectiveness of the solidification performance of the polymer organogelator to find the most efficient operational conditions.The main findings of this thesis were reported in three studies:1.   Development of magnetic polystyrene nanocomposite by grafting polystyrene chains on the surface of silica-coated iron oxide nanoparticles (IONP) and use as an oil solidifier. Styrene was polymerized on the surface of iron oxide nanoparticles using surface-initiated atom transfer radical polymerization (SI-ATRP) to make polystyrene-grafted silica-coated IONP (PS-SiO2-IONP). The chemical and physical properties of PS-SiO2-IONP were measured by field emission high-resolution scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Polystyrene provided the required porous structure, hydrophobicity, and oleophilicity for excellent oil absorption. The results showed that the oil absorption capacity of the polystyrene magnetic nanocomposite was 5 g oil/g absorbent for diluted bitumen and 3 g oil/g absorbent for diesel. I also made polystyrene with different molecular weights and blended them with PS-SiO2-IONP. Interestingly, the oil absorption tests showed that a blend with a weight composition of 91 % polystyrene and 9 % PS-SiO2-IONP nanocomposite had an oil absorption capacity equal to the pure PS-SiO2-IONP nanocomposite.2.    Synthesis of a novel phase-selective poly(styrene-co-10-undecenoic acid) (PS10UA) organogelator and use as an oil solidifier for oil recovery from biphasic oil/water mixtures. The novel copolymers performed well, gelling diluted bitumen and diesel spilled on water. The oil gelling ability of PS10UA depends on the 10-undecenoic acid (10UA) content and oil type. PS10UA with 10UA molar composition of 4.5 % and 3.5 % had the highest oil removal efficiency for diluted bitumen and diesel, respectively. Rheological measurements confirmed the mechanical strength and SEM revealed the fibrillar morphology and 3D network structure of the gels. FTIR measurements of the gels suggested that hydrogen bonding is mainly responsible for the gel formation, while Van der Waals forces and π-π stacking interactions promote the gelation. 3. Investigation of solidifier:oil ratio and contact time of PS10UA on solidification effectiveness in removing diluted bitumen from the water surface. PS10UA was most efficient at a solidifier:oil ratio of 1:8 after 15 minutes. I also studied the influence of the bulk density (particle size) of PS10UA on its oil removal performance and found that PS10UA organogelators with lower bulk density performed better by speeding up the dissolution process.</p>