Zenkina, Olena V

The oil sands industry is producing large volumes of tailings waste reaching 2 billion cubic meters by 2034 In this study, the industrial standard flocculant, high molecular weight PAM, was grafted from the surface of activated carbon (AC). This material was designed to increase the flocculant's hydrophobicity and density. Different molecular weight PAM was grafted from AC with different AC contents and particle sizes (AC-PAMs). The AC-PAMs were synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP). The AC-PAMs achieved molecular weights 107 – 5,600 kg/mol and AC content of 0.2 – 5.8% on <0.1 and 0.1 – 0.5 mm AC particle diameters. AC-PAM achieved higher solids contents up to 51 wt% using AC-PAM with 5.1 wt% AC due to the grafting from a hydrophobic AC core. To summarize, our work shows the successful grafting of PAM from AC and its potential as a flocculant for mature fine tailings.

Author Keywords: activate carbon, atom transfer radical polymization, flocculation, grafting-from, polyacrylamide, surface-initiated polymerization

N-Heterocyclic Carbenes (NHCs) have significantly impacted organometallic chemistry as ligands in transition metal catalysis, offering strong electron-donating properties and high bond dissociation energies. However, their structural versatility is limited by the scarcity of commercial precursors and challenging modification procedures. Furthermore, we have investigated its coordination to transition metals; copper, silver, and palladium. We further demonstrate the effects of its steric parameters by utilizing the Suzuki-Miyaura cross-coupling of aryl chlorides using [(RO-NHC)Pd(allyl)Cl] as precatalysts. This study demonstrates increased catalyst activity with bulkier ligands in Suzuki-Miyaura cross-coupling reactions. We also present simplified procedures for copper NHC complexes using triethylamine with no requirements for special equipment and techniques. Preliminary investigations towards a more economical approach to measuring the electron donating abilities of NHCs were conducted using CuI and AgI cyanide complexes as probes. The outcomes of this research may contribute to the growing research in the applications of NHCs as ligands in catalysis.

Author Keywords: Catalysis, Ligand synthesis, N-Heterocyclic carbenes, Organic Chemistry, Organometallic Chemistry, Transition metal catalysis

This thesis presents the design, synthesis, and evaluation of activated carbon polyacrylamide (AC-PAM) composites for oil sands tailings remediation, integrating flocculation and adsorption functionalities. Surface-initiated atom transfer radical polymerization (SI-ATRP) was employed to graft high molecular weight PAM brushes onto petroleum coke and commercial activated carbon, with SARA-ATRP yielding the most uniform architecture (Mn ≈ 5.2 kg/mol, Đ ≈ 1.25). Flocculation tests using mature fine tailings (MFT) revealed superior sedimentation and dewatering with SARA-ATRP composites, outperforming conventional PAM at lower dosages. Adsorption studies using benzoic acid and model naphthenic acids showed selective uptake governed by polymer brush morphology and molecular structure, with Dubinin–Radushkevich isotherms best capturing the behavior of ARGET-ATRP composites. Post-flocculation assays confirmed reduced metal and polymer contamination, validating dual-function efficacy. These findings underscore petcoke's viability as a sustainable substrate and highlight controlled polymerization as a critical driver for tuning composite performance in industrial water treatment.

Author Keywords: Activated Carbon, Adsorption, Atom Transfer Radical Polymerization, Dubinin–Radushkevich, Isotherm, Polyacrylamide