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Polystyrene bis(salicylaldehyde)-propylene-1,3-diiminato Cobalt (II) (salen) and Polystyrene bis(acetylacetone)-propylene-1,3-diiminato Cobalt (II) (BAE) were prepared stepwise from polystyrl chloride. The reaction series included substitution of the chloride with a malononitrile carbanion, reduction to a diamine, condensation to form a Schiff base, and complexation with Co(II) acetate to form the active polymeric material. Optimum conditions with regard to time, temperature, reaction ratios, and solvent were determined for each reaction. The ability of the polymer bound cobalt complex to oxidize 3-methyl indole was measure. The BAE catalyst yielded a large amount of the corresponding o-formylaminoacetophenone. However, the exact yield is not known because product could not be separated from the indole. The salen catalyst showed starting material with a small indication of product.

Copolymer-cobalt complexes have been formed by thermolysis of dicobalt octacarbonyl in solutions of copolysiloxanes. The copolysiloxane-cobalt complexes formed from toluene solutions of PDMS-b-[PMVS-co-PMTMS] block copolymers were annealed at 600-700 °C under nitrogen to form protective siliceous shells around the nanoparticles. Magnetic measurements after aging for several months in both air and in water suggest that the ceramic coatings do protect the cobalt against oxidation. However, after mechanical grinding, oxidation occurs. The specific saturation magnetization of the siliceous-cobalt nanoparticles increased substantially as a function of annealing temperature, and they have high magnetic moments for particles of this size of 60 emu g⁻¹ Co after heat-treatment at temperatures above 600 °C. The siliceous-cobalt nanoparticles can be re-functionalized with aminopropyltrimethoxysilane by condensing the coupling agent onto the nanoparticle surfaces in anhydrous, refluxing toluene. The concentration of primary amine obtained on the surfaces is in reasonable agreement with the charged concentrations. The surface amine groups can initiate L-lactide and the biodegradable polymer, poly(L-lactide), can be polymerized directly from the surface. The protected cobalt surface can also be re-functionalized with poly(dimethylsiloxane) and poly(ethylene oxide-co-propylene oxide) providing increased versatility for reacting polymers and functional groups onto the siliceous-cobalt nanoparticles.Phthalonitrile containing graft copolysiloxanes were synthesized and investigated as enhanced oxygen impermeable shell precursors for cobalt nanoparticles. The siloxane provided a silica precursor whereas the phthalonitrile provided a graphitic precursor. After pyrolysis, the surfaces were silicon rich and the complexes exhibited a substantial increase in Ms. Early aging data suggests that these complexes are oxidatively stable in air after mechanical grinding. Aqueous dispersions of macromolecule-magnetite complexes are desirable for biomedical applications. A series of vinylsilylpropanol initiators, where the vinyl groups vary from one to three, were prepared and utilized for the synthesis of heterobifunctional poly(ethylene oxide) oligomers with a free hydroxy group on one end and one to three vinylsilyl groups on the other end. The oligomers were further modified with carboxylic acids via ene-thiol addition reactions while preserving the hydroxyl functionality at the opposite terminus. The resulting carboxylic acid heterobifunctional PEO are currently being investigated as possible dispersion stabilizers for magnetite in aqueous media. / Ph. D.

Nowadays, Lithium-ion batteries (LIBs) have dominated the power source market in a variety of applications. Lithium cobalt oxide (LiCoO2) is one of the most common cathode materials for LIBs in consumer electronics. The recycling of LIBs is important because cobalt is an expensive element that is dependent on foreign sources for production. Lithium-ion batteries need to be recycled and disposed properly when they reach the end of life (EOL) to avoid negative environmental impact. This project focuses on recycling cathode material (LiCoO2) by direct method. Two automation stages, tape peeling stage and unrolling stage, are designed for disassembling prismatic winding cores. Different sintering conditions (e.g., temperature, sintering atmosphere, the amount of lithium addition) are investigated to recycle EOL cathode materials. The results show that the capacity of the recycled cathode materials increases with increasing temperature. The extra Li addition leads to worse cycling performance. In addition, the sintering atmosphere has little influence on small- scale sintering. Also, most of directly recycled cathode materials have better electrochemical (EC) performance than commercial LiCoO2 (LCO) from Sigma, especially when cycling with 4.45V cutoff voltage. / Master of Science / Nowadays, Lithium-ion batteries (LIBs) have dominated the power source market in a variety of applications. A LIB contains an anode, a cathode and electrolyte. The cathode material is the most valuable component in the LIB. Lithium cobalt oxide (LiCoO2) is one of the most common cathode materials for LIBs in consumer electronics. The recycling of LIBs is important because cobalt is an expensive element that is dependent on foreign sources for production. Lithium-ion batteries need to be recycled and disposed properly when they reach end of life (EOL) to avoid negative environmental impact. The direct recycling is a cost effective and energy conservative method which can be divided into two steps: retrieving the cathode materials from EOL LIBs and regenerating the cathode materials. This project focuses on recycling LiCoO2 by direct method. Two automation modules, tape peeling stage and unrolling stage, are designed for a disassembling line which is the automation line to collect the cathodes materials. The EOL cathode materials is lithium deficient (Li1-xCoO2). To regenerate the EOL cathode materials, lithium is added into structure of cathode materials which is called the re-lithiation process. The different sintering conditions (e.g., temperature, sintering atmosphere, the amount of lithium addition) are investigated for the re-lithiation process. The results show that the capacity of the recycled cathode materials increases with increasing temperature. The extra Li addition in iv Li1-xCoO2 leads to worse cycling performance. In addition, sintering atmosphere has little influence on small- scale sintering. Most of directly recycled cathode materials have better electrochemical (EC) performance than commercial LiCoO2, especially when cycling with 4.45V cutoff voltage.

The treatment of gamma-Fe₂O₃ with cobalt(II) is an important commercial process since the product is used extensively as a magnetic material for magnetic recording. The preparation of cobalt-doped gamma-Fe₂O₃ consists of interacting Co(II) with particulate gamma-Fe₂O₃ in solution under alkaline conditions. The surface of cobalt-treated gamma-Fe₂O₃ was characterized using the surface analysis techniques of x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS). Characterization was also accomplished using infrared spectroscopy and quantitative analysis. Surface analysis results suggest that the Co(II) is initially adsorbed as a hydrous precipitate during base addition (NaOH or NH₄OH). Following base addition, the reaction suspension was heated to 90-95°C. Results from surface analysis indicate that during this warm up period there is a conversion from the hydrous surface to a surface with a composition near CoFe₂O₄ (cobalt ferrite). No oxidation of Co(II) to Co(III) was observed. Surface analysis also suggests that cobalt-treated γ-Fe₂O₃ prepared using NaOH has a different surface chemistry than cobalt-treated γ-Fe₂O₃ prepared with NH₄OH. Following the adsorption of Co(II) on γ-Fe₂O₃ the product underwent a thermal treatment to enhance the coercivity. Surface analysis results indicate that the thermal treatment causes a significant diffusion of Co(II) into the bulk γ-Fe₂O₃. The results also suggest that the coercivity enhancement following thermal treatment is largely due to the inward diffusion of Co(II) and not a change in the surface composition of the cobalt-treated γ-Fe₂O₃. / Master of Science