| The primary focus of this thesis is the synthesis of copper-nickel nanoparticles and thin films in a high temperature reducing jet (HTRJ) reactor. The HTRJ reactor, which is powered by a hydrogen flame, is an environmentally friendly and low-cost approach for the production of metal (and metal alloy) nanomaterials. The key feature of the HTRJ reactor is the separation of the combustion and particle formation steps, which are typically coupled in related flame-based aerosol approaches. Because the reactor runs with excess hydrogen, the metal oxides that would ordinarily be produced in a traditional flame spray setup are reduced to the corresponding pure metals. The precursors are injected into the reactor via a converging-diverging nozzle with four symmetrically placed inlets. The precursors are atomized, vaporized, and thermally decomposed by the hot combustion gases flowing through the nozzle throat. This design makes the HTRJ reactor an ideal choice for one-step synthesis of multicomponent nanoparticles.;The electrical conductivity of copper is comparable to that of silver, but in the context of conductive inks and printed electronics, it is the low cost and natural abundance of copper that make this element particularly attractive. The one critical drawback of copper nanomaterials is their tendency to oxidize under ambient conditions, which results in a lower electrical conductivity. It is a well-established fact, however, that this problem can be circumvented to some extent by the addition of nickel. The goal of this thesis is to provide convincing evidence of the HTRJ reactor's capabilities in synthesizing copper-nickel nanoparticles and that the oxidation resistance of said nanoparticles are sufficient for the replacement of silver nanomaterials in conductive inks.;Included in this thesis are a brief review of nanoparticles synthesis methods, a description of how the HTRJ reactor works, and the mechanisms of the reactions at play in the HTRJ process. The synthesis of copper-nickel nanoparticles and the materials characterization results are presented in the latter part of the thesis. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM).;The thesis ends with some concluding thoughts about the advantages of copper-nickel nanomaterials and also general suggestions for future research on the HTRJ reactor. |
