Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Functional nanoparticles have garnered considerable attention due to their intriguing physical properties at the nanoscale for a broad range of applications, such as photocatalysis, capacitive energy storage, thermoelectric power generation, solar energy harvesting, flexible and transparent electronics, drug delivery, biomolecular electronics, and analytic chemistry, etc. Successful synthesis of nanoparticles and precise control over their shapes are critical to achieving desired functions. In the first part of my thesis, an effective synthetic route to plain nanoparticles is briefly introduced. Based on this general route, the synthesis of solid iron oxide nanoparticles and a slightly modified synthetic method of solid silica nanoparticles are presented in detail. In the second part of my thesis, simulation of optical absorption spectra and plasmonic near-field maps of gold nanoparticle and gold/titanium oxide nanoparticle are explored, and the effectiveness of simulation in predicting, optimizing, and guiding experimental design is emphasized.

Port-au-Prince, Haiti, along with many dense cities in developing countries, are stifled by their rudimentary, undersized and poorly maintained waste, water and sanitation infrastructural systems. Port-au-Prince is a city already plagued by poverty and overpopulation, and suffered a magnitude 7.0 earthquake in 2010 that devastated the already fragile republic. Flooded with Not-for-Profit and Non-Government Organizations (NFPs and NGOs) and billions of dollars of aid money following the earthquake, a new challenge arose in finding ways to utilize these new, uncoordinated resources efficiently without falling victim to dependency on aid money and other fleeting, external resources. The thesis proposes a series of infrastructural components for decentralized waste, water and sanitation that can address the cultural and infrastructural challenges of diverse sites within city, as city-wide systems have proved unsuitable and have not been maintained. The proposal deals with resources and wastes on-site, in order to reduce dependence on often expensive methods of waste collection and water provision. It diverts waste and excess water from ravines; reduces waste strewn throughout the city; creates community accountability and engagement, and in doing so, strives to improve quality of life. Waste is furthermore utilized in fueling other complementary processes, generating a micro-scale waste economy. The solution to making Port-au-Prince’s infrastructural systems viable and self-sustaining is to turn them into economic drivers that produce businesses and jobs through the collection, sorting, processing and re-use of wastes and water that in turn result in safer and more sanitary living conditions, as well as helping to re-organize a city destroyed by the earthquake into productive neighbourhoods with local community nodes.

The understanding of nucleation and growth of metals on a planar support at the atomic level is critical for both surface science research and heterogeneous catalysis studies. In this dissertation, two planar substrates, including graphene and ultra-thin silica film were employed for supported model catalysts studies. The structure and stability of several catalytically important metals supported on these two substrates were thoroughly investigated using scanning tunneling microscopy (STM) coupled with other traditional surface science techniques. In the study of the graphene/Ru(0001) system, the key factors that govern the growth and distribution of metals on the graphene have been studied based on different behaviors of five transition metals, namely Pt, Rh, Pd, Co, and Au supported on the template of a graphene moire pattern formed on Ru(0001). Both metal-carbon (M-C) bond strength and metal cohesive energies play significant roles in the cluster formation process and the M-C bond strength is the most important factor that affects the morphology of clusters at the initial stages of growth. Interestingly, Au exhibits two-dimensional (2-D) structures that span several moire unit cells. Preliminary data obtained by dosing molecular oxygen onto CO pre-covered Au islands suggest that the 2-D Au islands catalyze the oxidation of CO. Moreover, graphene/Ru(0001) system was modified by introducing transition metals, oxygen or carbon at the interface between the graphene and Ru(0001). Our STM results reveal that the geometric and/or electronic structure of graphene can be adjusted correspondingly. In the study of the silica thin film system, the structure of silica was carefully investigated and our STM images favor for the [SiO4] cluster model rather than the network structure. The nucleation and adsorption of three metals, namely Rh, Pt and Pd show that the bond strength between the metal atom and Si is the key factor that determines the nucleation sites at the initial stages of metal deposition. The annealing effect studies reveal that Rh and Pt atoms diffuse beneath the silica film and form the 2-D islands that are covered with a silica thin film. In contrast, the formation of Pd silicide was observed upon annealing to high temperatures.

Port-au-Prince, Haiti, along with many dense cities in developing countries, are stifled by their rudimentary, undersized and poorly maintained waste, water and sanitation infrastructural systems. Port-au-Prince is a city already plagued by poverty and overpopulation, and suffered a magnitude 7.0 earthquake in 2010 that devastated the already fragile republic. Flooded with Not-for-Profit and Non-Government Organizations (NFPs and NGOs) and billions of dollars of aid money following the earthquake, a new challenge arose in finding ways to utilize these new, uncoordinated resources efficiently without falling victim to dependency on aid money and other fleeting, external resources. The thesis proposes a series of infrastructural components for decentralized waste, water and sanitation that can address the cultural and infrastructural challenges of diverse sites within city, as city-wide systems have proved unsuitable and have not been maintained. The proposal deals with resources and wastes on-site, in order to reduce dependence on often expensive methods of waste collection and water provision. It diverts waste and excess water from ravines; reduces waste strewn throughout the city; creates community accountability and engagement, and in doing so, strives to improve quality of life. Waste is furthermore utilized in fueling other complementary processes, generating a micro-scale waste economy. The solution to making Port-au-Prince’s infrastructural systems viable and self-sustaining is to turn them into economic drivers that produce businesses and jobs through the collection, sorting, processing and re-use of wastes and water that in turn result in safer and more sanitary living conditions, as well as helping to re-organize a city destroyed by the earthquake into productive neighbourhoods with local community nodes.

Thèse (Ph. D.)--Université Laval, 2007. / Bibliogr.: f. [154]-157. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Chemnitz, Techn. Univ., Magisterarb., [2006].

Thèses (M.A.)--Université de Sherbrooke (Canada), 2001. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèses (M.Sc.A.)--Université de Sherbrooke (Canada), 2001. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèse--Sc. phys.--Paris VI, 1983. / Bibliogr. p. 247-256.