abstract: Nanomaterials exhibit unique properties that are substantially different from their bulk counterparts. These unique properties have gained recognition and application for various fields and products including sensors, displays, photovoltaics, and energy storage devices. Aerosol Deposition (AD) is a relatively new method for depositing nanomaterials. AD utilizes a nozzle to accelerate the nanomaterial into a deposition chamber under near-vacuum conditions towards a substrate with which the nanomaterial collides and adheres. Traditional methods for designing nozzles at atmospheric conditions are not well suited for nozzle design for AD methods. Computational Fluid Dynamics (CFD) software, ANSYS Fluent, is utilized to simulate two-phase flows consisting of a carrier gas (Helium) and silicon nanoparticles. The Cunningham Correction Factor is used to account for non-continuous effects at the relatively low pressures utilized in AD. The nozzle, referred to herein as a boundary layer compensation (BLC) nozzle, comprises an area-ratio which is larger than traditionally designed nozzles to compensate for the thick boundary layer which forms within the viscosity-affected carrier gas flow. As a result, nanoparticles impact the substrate at velocities up to 300 times faster than the baseline nozzle. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2017

[pt] Os ativos de produção da indústria petrolífera estão atingindo reservas de petróleo em maiores profundidades e condições ambientais mais diversas impostas pelo subsolo marinho, neste cenário os problemas ocasionados pela corrosão acarretam maiores perdas econômicas. O CO2 está presente na indústria petrolífera geralmente através da queima de hidrocarbonetos, sendo que o CO2 forma com a água o ácido carbônico (H2CO3) que gera grave corrosão nos metais em contato. Esta pesquisa avaliou o desempenho de um revestimento comercial de base polimérica reforçado com nanotubos de carbono e de outro revestimento de resina epóxi NOVOLAC, ambos aplicados sobre o aço carbono AISI 1020. Estes corpos de prova revestidos foram imersos em uma solução salina com 3 porcento wt de NaCl e em outra solução salina com 3,5 porcento wt de CaCl2, ambas saturadas com CO2., pressão de 75 bar, temperatura de 75 graus C e tempo de imersão de 360 horas. Foram empregadas técnicas de Espectroscopia de Impedância Eletroquímica (EIS), Microscopia Eletrônica de Varredura (MEV), Espectroscopia de Energia Dispersiva (EDS) e Difração de Raios X (DRX). Os resultados mostraram que o revestimento de resina epóxi NOVOLAC apresentou o melhor desempenho em ambos os meios para as condições utilizadas neste trabalho. / [en] The production assets of the oil industry are reaching oil reserves at greater depths and more diverse environmental conditions imposed by the marine subsoil, in this scenario the problems caused by corrosion lead to greater economic losses. CO2 is present in the petroleum industry generally through the burning of hydrocarbons, with CO2 forming the acidic acid (H2SO3) that generates severe corrosion in the metals. This study evaluated the performance of a nanoparticularized coating with carbon nanotubes and another NOVOLAC epoxy impregnated coating, both coating AISI 1020 carbon steel. These coated specimens were immersed in a saline solution containing 3 percent wt NaCl and in another saline solution with 3.5 percent wt CaCl2, both saturated with CO2, 75 bar of pressure, 75 celsius degrees and immersion for 360 hours. Techniques such as Electrochemical Impedance Spectroscopy (EIS), Scanning Electron Microscopy (SEM), Dispersive Energy Spectroscopy (EDS) and X-ray Diffraction (XRD) were used. The results showed that the NOVOLAC epoxy coating showed the best performance in both saline solutions for the conditions studied.