Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-03-17T10:45:40Z No. of bitstreams: 0 / Made available in DSpace on 2015-03-17T10:45:40Z (GMT). No. of bitstreams: 0 / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Submitted by PEDRO HENRIQUE SUMAN null (phsuman@yahoo.com.br) on 2016-10-01T00:34:00Z No. of bitstreams: 1 Tese_Pedro_Final_novo.pdf: 17387364 bytes, checksum: 4749ea76239f897a32a707ec991707c0 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-10-04T17:39:33Z (GMT) No. of bitstreams: 1 suman_ph_dr_araiq.pdf: 17387364 bytes, checksum: 4749ea76239f897a32a707ec991707c0 (MD5) / Made available in DSpace on 2016-10-04T17:39:33Z (GMT). No. of bitstreams: 1 suman_ph_dr_araiq.pdf: 17387364 bytes, checksum: 4749ea76239f897a32a707ec991707c0 (MD5) Previous issue date: 2016-06-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Neste trabalho, as propriedades sensoras de gás de nanoestruturas de óxido de estanho puras (SnO2) e híbridas (SnO2-Pt, SnO2-CuO e SnO2-CuO-Pt) foram estudadas na presença de diferentes gases. Os materiais foram sintetizados pelo método de electrospinning seguido por tratamento térmico e, posteriormente, foram caracterizados por termogravimetria (TG), difração de raios X (DRX), microscopia eletrônica de varredura com emissão por campo (MEV-FEG), microscopia eletrônica de transmissão (MET), espectroscopia por dispersão em energia de raios X (EDS), microscopia de força atômica (AFM) e área de superfície específica e porosidade (BET). O foco principal do trabalho foi analisar a resposta dos materiais sintetizados como sensores de gás para a detecção de gases tóxicos e inflamáveis em baixas concentrações e em uma temperatura de operação de 300 °C. Os resultados obtidos a partir das caracterizações estruturais e morfológicas mostraram que o método de electrospinning permite a obtenção de materiais unidimensionais (1D) policristalinos com elevada homogeneidade morfológica e pureza cristalina. Além disso, os elementos químicos presentes nas estruturas de cada material sintetizado foram mapeados e identificados, onde verificou-se que todos os elementos estão homogeneamente distribuídos ao longo da estrutura das fibras. As características superficiais dos materiais, tais como rugosidade e porosidade também foram estudadas e os resultados indicaram que, dependendo da composição química das fibras, estruturas com diferentes níveis de rugosidade e área superficial podem ser obtidas. Medidas elétricas na presença de NO2, CO, H2, e CH4 mostraram que todos os materiais exibem comportamento de semicondutor do tipo-n e resposta sensora dependente da concentração do gás analito. As fibras de SnO2 e SnO2-Pt exibiram maior resposta sensora para a detecção de NO2 enquanto as fibras de SnO2-CuO e SnO2-CuO-Pt tiveram maior resposta na presença de H2, além de elevada seletividade para H2 em relação ao CH4. Em geral, os resultados obtidos mostram que os materiais produzidos são bastante promissores e têm grande potencial para serem estudados detalhadamente como sensores de gás. / In this work, the gas sensing properties of pure (SnO2) and hybrid (SnO2-Pt, SnO2-CuO and SnO2-CuO-Pt) tin oxide nanostructures were studied in the presence of different analyte gases. Materials were synthesized by electrospinning method followed by thermal treatment and subsequently characterized by thermogravimetry (TG), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM) and specific surface area and porosity (BET). The main focus of the work was to analyze the gas sensor response of the synthesized materials for the detection of toxic and flammable gases in low concentrations at 300 °C. The results from the morphological and structural characterizations by XRD, SEM and TEM showed the electrospinning method allows obtaining polycrystalline 1D materials with high morphological homogeneity and crystalline purity. Furthermore, the chemical elements present in the structures of each synthesized material and it was found that all elements are homogeneously distributed throughout the fiber structures. The surface characteristics of materials, such as roughness and porosity were also studied and the results indicated that depending on the chemical composition of the fibers, structures with different levels of roughness and surface area can be obtained. Electrical measurements in the presence of NO2, H2, CO and CH4 were performed in order to verify the gas sensor properties of the nanostructures, and results showed that all materials exhibit n-type semiconducting behavior and the sensor response to be dependent on the analyte gas concentration. The SnO2 and SnO2-Pt fibers showed higher sensor response to NO2 detection while SnO2-CuO and SnO2-CuO-Pt fibers presented greater sensitivity for H2 as well as high selectivity to H2 compared to CH4. In general, the results showed that the produced materials are very promising and have high potential to be studied in detail as gas sensors materials. / FAPESP: 2012/11139-7

Made available in DSpace on 2015-05-14T12:14:20Z (GMT). No. of bitstreams: 1 arquivototal.PDF: 1477225 bytes, checksum: b58b2d65df7708c6e4437db3a0167e5a (MD5) Previous issue date: 2010-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work we studied the quantum dynamics of particles in a non-euclidian space. First, we studied the dynamics of a particle in a space with a linear topological defect, by confinement potential which mimics different mesoscopic systems [1, 2, 3]. By the effective mass approach [4, 5], one can apply our results to semiconductor nanostructures. Second, we studied the quantum dynamics of a particle, also in the effective mass approach, for the confinement in a spherical space. The confinement potential presented is alike the one in reference [7], but now fitted to a surface with positive curvature. We studied the dynamics for the spherical space in two situations: with and without including a topological defect. Third, we studied, both relativistic and non-relativistic, for a space with a density of defects. Some results from this thesis were published in references [8, 9]. / Neste trabalho estudamos a dinâmica de partículas em um espaço não-euclidiano. Inicialmente, estudamos a dinâmica de uma partícula em um espaço com um defeito topológico linear, para um confinamento através de um potencial que consegue modelar diferentes sistemas mesoscópicos [1, 2, 3]. Através da abordagem de massa efetiva [4, 5], pode-se aplicar nossos resultados a nanoestruturas semicondutoras. Em um segundo momento, estudamos a dinâmica quântica de uma partícula, também na abordagem de massa efetiva, para o confinamento em um espaço esférico. O potencial confinante tratado é similar ao da referência [7], só que agora ajustado para uma superfície de curvatura positiva. Estudamos a dinâmica para o espaço esférico em duas situações: com e sem a inserção de um defeito topológico. Em um terceiro momento, estudamos a dinâmica, tanto relativística quanto não relativística, para um espaço com uma densidade de defeitos. Parte dos resultados desta tese foram publicados nas referências [8, 9].

Thesis submitted in fulfilment of the requirements for the degree Magister of Technology: Dental Technology In the Faculty of Health and Wellness Sciences At the Cape Peninsula University of Technology, 2012 / A study of the modification of dental nanocomposites with nanosized fillers is presented. The incorporation of TiO2 (titania) nanoparticles, via a silane chemical bond, to a standard dental acrylic resin matrix was explored to determine whether there was an increase in the wear resistance, flexural strength and surface hardness properties of the dental nanocomposites. The principal aim of this study was to synthesize dental nanocomposites with different sizes, treated, nano-TiO2 fillers in urethane dimethacrylate (UDMA) for potential application in posterior restoration and to evaluate their mechanical properties. Treatment of the nano-TiO2 particles was carried out with a silane coupling agent, 3-(methacryloyloxy)propyltrimethoxysilane (MPTMS), to improve bonding between the nano-TiO2 particles and acrylic matrix (UDMA), and reduce agglomeration of the nano-TiO2. Characterisation of products was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR). TEM results were used to compare the particle size distributions of untreated TiO2 and treated TiO2 under various experimental conditions in an ethanol solvent, while SEM images showed the adhesion between the matrix (UDMA) and the nano-TiO2. FTIR was used to show the qualitative composition of untreated TiO2 and treated TiO2. Eighteen groups of experimental dental nanocomposites were evaluated. Each group contained different average particle sizes of nano-TiO2 (filler): 5 nm, 21 nm and 80 nm. Each particle size category was treated with three different concentrations of the silane, (MPTMS): 2.5, 10 and 30 wt %. Samples were prepared by mixing the monomer resin matrix of UDMA and nano-TiO2 particles. For comparison, a commercially available dental resin was reinforced with untreated and treated nano-TiO2 particle sizes 5, 21 and 80 nm. Wear resistance, flexural strength and surface hardness of TiO2 nanocomposites treated with 2.5 wt % MPTMS were significantly higher compared to those treated with 10 and 30 wt% MPTMS. The nanocomposites with 5 nm TiO2 had higher wear loss, lower flexural strength and lower surface hardness values compared to those with 21 nm and 80 nm TiO2. Statistical analysis showed that the effect of the concentrations of MPTMS on wear resistance and surface hardness of specimens was significant (p<0.001), which is less than 0.05, while the effect of the concentration of MPTMS on flexural strength was statistically not significant, (p=0.02). Control composites reinforced with treated 80 nm TiO2 particles had much better mechanical properties than any of the other specimens. It was concluded that the most available commercial product for dental restorations could be improved by the addition of nano-TiO2 with relatively large particle size.

Made available in DSpace on 2014-06-11T19:30:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-10-19Bitstream added on 2014-06-13T19:39:42Z : No. of bitstreams: 1 muradorfilho_a_me_bauru.pdf: 1523059 bytes, checksum: b7492203fa42c21510e2cb2a14614f56 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O campo dos nanomateriais tem se expandido enormemente nas últimas décadas principalmente devido às suas propriedades especiais. As experiências descritas na literatura em grande gama de aplicações mostram propriedades elétricas, magnéticas, ópticas e outras, extremamente aperfeiçoadas com relação aos sisstemas macroscópios. A ciência e tecnologia trabalham atualmente com inúmeras técnicas químicas para a obtenção de óxidos e dentre elas destaca-se o Método Poliol por ser vantajoso e adequado na preparação de nanopartículas com variadas morfologias, dimensões e crisalinidade. Entretanto, poucos estudos foram realizados sobre a síntese e a caracterização de compósitos com o propósito de investigar as propriedades resultantes da possível sinergia obtida a partir da interação entre dois óxidos nanoestruturados. Este trabalho teve como objetivo a síntese e a caracterização de compósito nanoestruturado formado de dois óxidos multifuncionais: o óxido de zinco e o dióxido de titânio. Para a síntese foram utilizados o acetato de zinco dihidratado e o isopropóxido de titânio para a obtenção do ZnO e do TiO2, respectivamente. o compósito foi obtido pelo Método Poliol a partir da interrupção momentânea da síntese dos óxidos isolados seguido da mistura das soluções. O compósito, assim como os óxidos sintetizados isoladamente, foram caracterizados po9r difração de raios X (DRX), análise térmicas (TG/DTA), medidas de adsorção de gás nitrogênio (BET), microscopia eletrônica de varredura (MEV), espectroscopia de adsorção de luz na região do ultravioleta, visível e infravermelho, espectroscopia Raman. O compósito formado pelo Método Poliol apresentou o ZnO na forma aglomerado, porém nanoestruturado, e o TiO2 após tratamento térmico de 400º C. Foi verificada ainda a presença de resíduos orgânicos nos materiais como... (Resumo completo, clicar acesso / The field of nanomaterials has expanded greatly in recent decades mainly due to its special propoerties. The experiments described in the literature in a wide variety of applications show electrical properties, magnetic, optical and others, extremely improvement properties with respect to macroscopic systems. Science a technology are currently working with numerous chemical techniques to achieve oxides and them stands out the Polyol Method to be advantageous and appropriate in the preparation of nanoparticles with various morphologies, size and crystallinity. However, few studies have been done on the synthesis and characterization of composites in order to investigate the resultants properties from possible synergy obtained from the interaction between two nanoestructured oxides. This work aimed to the synthesis and characterization nanostructured composites formed by two multifunctional oxides, zinc oxide and titanium dioxide. For the synthesis were used zinc acetate dihydrate and titanium isopropoxide to obtain the ZnO and TiO2, respectively. The composite was obtained by Polyol from the interruption of the synthesis of single oxides followed by mixing the solutions. The composite, as weell as oxides separately synthesized, were characterized by X-ray diffraction (XRD), thermal analysis (TG/DTA), meassurements of nitrogen gas adsorption (BET), scanning electron microscopy (SEM), YV-VIS and IR absorption spectroscopy and Raman spectroscopy. The composite obtained by the Polyol Method presented ZnO as agglomerate, however nanostructured, and TiO2 after heat treatment of 400ºC. It was also verified the presence of organic waste in the materials as synthesized and titanium glycolate as an intermediate in the reaction of titanium dioxide. A comparison of optical behavior, as synthesized composite formed by ZnO and titanium... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:30:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-29Bitstream added on 2014-06-13T20:40:14Z : No. of bitstreams: 1 sereguetti_jm_me_bauru.pdf: 655401 bytes, checksum: f8b80337046a58d12f1aed1d4dc5a28c (MD5) / Os cristais fotônicos têm recebido grande atenção da comunidade científica nos últimos anos. As suas aplicações incluem a construção de guias de onda, chips ópticos e células solares, o controle de emissão de radiação e o gerenciamento de informações. Neste trabalho são calculados os modos de propagação de ondas eletromagnéticas em cristais fotônicos bidimensionais. Os cristais estudados são arranjos de fios circulares infinitos de um tipo de meio óptico, imersos numa matriz de outro meio óptico. As estruturas cristalinas consideradas são a quadrada simples, hexagonal simples e honeycomb. É analisada a propagação perpendicular aos fios e, portanto, são consideradas duas polarizações: a transversão elétricas e a transversal magnética. Os cálculos numéricos são realizados para diferentes combinações dos materiais que compõem o cristal fotônico. Isto permite investigar como o espectro fotônico depende da geometria do cristal e do contraste entre os meios ópticos que o compõem. Para resolver a equação de ondas, o campo eletromagnético é expresso como combinação linear de um conjunto de ondas harmônicas planas. Foi encontrado bom acordo entre as frequencia calculadas e resultados disponíveis na literatura do tema, corroborando a existência de gaps fotônicos parciais nas estrutuaras simples e gaps fotônicos completos na estrutura honeycomb. Além disso, verificou-se que o surgimento de gaps requer menor constrate de índice de refração no caso hexagonal, quando comparado com o quadrado / Photoic crystals have received some attention from the scientific community in the las years. Their applications include the fabrication of waveguides, optical chips and solar cells, control of radiation emission and information management. In this work, the propagation of electromagnetic waves in two-dimensional photonic crystals is theoretically investigated. The structures under study are periodic arrangements of infinite circular wires of a given optical medium, immersed in a matrix of another optical medium. The considered cyrstalline structures are the simple square, the simple hexagonal and the honeycomb lattices. Only the propagation perpendicular to the wires is analyzed. Hence, we consider two polarizations: transverse electrical and transverse magnetic. The calculations are performed for different combinations of the materials composing the crystal. This allows the investigation of how the photonic spectrum depends on both the crystal geometry and the contrast between the refractuve index of the composing materials. The wave equation is solved by expressing the solution as a linear combination of a set of harmonic plane waves. Good agreement between the calculated frequencies and the results available in the literature is found, thus confirming the existence of partial photonic gaps in the simple lattices and complete photonic gaps in the honeycomb lattice. Moreover, it was verified that occurrence of gaps in the hexagonal case requires less refractive-index contrast, when compared with the square one

Le stockage de l'énergie est un domaine en pleine évolution. Le développement des énergies renouvelable et les besoins croissants d'autonomie énergétique (ordinateur portable, Smartphone, voiture électrique) impliquent le développement de nouvelles technologies, plus performantes, moins coûteuses et écologiquement satisfaisantes. Les batteries lithium-air sont vues comme une alternative prometteuse aux batteries lithium- ion, car elles ont une capacité théorique de stockage 2-3 fois plus élevée. La structuration et la réactivité à la cathode est un verrou important. La présente étude se focalise sur le compartiment positif de la cellule, dans lequel les réactions de l’oxygène sont mises en jeu. Dans un premier temps, des modifications de la surface des électrodes de travail qui puissent agir comme fournisseurs de diènes, en utilisant le mécanisme Diels Alder, sont faites afin de changer les propriétés physico-chimiques de surfaces carbonées. Puis, la chimie click a été utilisée comme une deuxième technique de greffage en montrant que l’hydrophobicité des liquides ioniques influe sur la forme de greffage sur la surface des électrodes. Ensuite ces deux mécanismes de greffage sont utilisés pour étudier la réaction de réduction de l’oxygène et la réactivité du superoxyde à l’interface d’une électrode de carbone qui joue le rôle de cathode. / Energy storage is an evolving field. The development of renewable energies and the growing needs for energy autonomy (laptop, smartphone, and electric car) imply the development of new technologies that are more efficient, less costly and ecologically satisfactory. Lithium-air batteries are seen as a promising alternative to lithium-ion batteries, because they have a theoretical storage capacity 2-3 times higher. Structuring and reactivity at the cathode is an important lock. The present study focuses on the positive compartment of the cell, in which the reactions of oxygen are involved. In a first step, modifications of the surface of the working electrodes which can act as diene suppliers, using the Diels Alder mechanism in order to change the physicochemical properties of carbon surfaces. Then click chemistry was used as a second grafting technique showing that the hydrophobicity of the ionic liquids affects the grafting form on the surface of the electrodes. Then these two grafting mechanisms were used to study the oxygen reduction reaction and the reactivity of the superoxide at the interface of a carbon electrode which functions as a cathode.

Atualmente, existem diversos produtos cosméticos de base nanotecnológica disponíveis no mercado nacional, incluindo protetores solares, produtos para a prevenção do envelhecimento cutâneo, ou ainda, produtos que veiculam uma ampla gama de componentes. Em contrapartida ao grande interesse industrial, várias organizações não governamentais têm expressado a sua preocupação acerca das incertezas do impacto dos novos nanomateriais sobre a saúde humana e sobre as possíveis aplicações e implicações sociais dessa nova tecnologia. Além disso, tem sido amplamente questionada a adequação dos atuais sistemas regulatórios governamentais no que diz respeito aos produtos oriundos da nanotecnologia. De fato, mundialmente, não existem requisitos específicos para o registro de produtos cosméticos de base nanotecnológica, sendo a análise realizada, de maneira geral, caso a caso. Dentro desse contexto, esse estudo traçou uma descrição do perfil da produção industrial de produtos cosméticos de base nanotecnológica no Brasil, buscando avaliar a disponibilidade dos mesmos no mercado nacional e a sua segurança de uso com base na análise das matérias primas constituintes dos produtos, determinação do seu diâmetro de partícula e dados disponíveis na literatura. Em uma última etapa, foram propostos alguns parâmetros para a regulação de produtos cosméticos de base nanotecnológica no Brasil, em especial, no que diz respeito à classificação dos produtos e a rotulagem dos mesmos. / There are a number of nanocosmetic products in the domestic market today, including sunblock, products for prevention against skin aging, or even products which circulate in a wide range components. Running counter to major industrial interests, many non-governmental organizations have expressed their concern regarding the uncertainties of the impact new nanomaterials may have on human health as well as the possible applications and social implications that this new technology may bring. Moreover, the adaptation of current governmental regulations has widely come under scrutiny regarding products stemming from nanotechnology. In fact, worldwide, there are no specific requirements to register nanotechological cosmetic products, as each is generally analyzed on a case by case basis. Within this context, this study traced the profile of the industrial production of nanotechnological cosmetic products in Brazil, with the aim of assessing the availability of these products in the domestic market and their safe usage based on the analysis of the raw materials which make up the products, the determining of particle diameter, and the data available in the literature. In the final stage, some parameters for the regulation of nanotechnological cosmetic products in Brazil are proposed, especially as regards the classification and labeling of products.

Porous, conductive metallic nanostructures are required in several fields, such as energy conversion, low-cost sensors etc. This thesis reports on the development of an electrocatalytically active and conductive membrane for use in Polymer Electrolyte Membrane Fuel Cells (PEMFCs) and fabrication of low-cost substrates for Surface Enhanced Raman Spectroscopy (SERS). One of the main challenges facing large-scale deployment of PEMFCs currently is to fabricate a catalyst layer that minimizes platinum loading, maximizes eletrocatalytically active area, and maximizes tolerance to CO in the feed stream. Modeling the kinetics of platinum catalyzed half cell reactions occurring in a PEMFC using the kinetic theory of gases and incorporating appropriate sticking coefficients provides a revealing insight that there is scope for an order of magnitude increase in maximum current density achievable from PEMFCs. To accomplish this, losses due to concentration polarization in gas diffusion layers, which occur at high current densities, need to be eliminated. A novel catalyst design, based on a porous metallic nanostructure, which aims to overcome the limitations of concentration polarization as well as minimize the amount of platinum loading in PEMFCs is proposed. Fabrication steps involving controlled in-plane fusion of self-assembled arrays of core-shell gold-platinum nanoparticles (Au@Pt) is envisioned. The key steps involved being the development of a facile synthesis route to form Au@Pt nanoparticles with tunable platinum shell thicknesses in the 5 nm size range, the formation of large-scale 2D arrays of Au@Pt nanoparticles using guided self-assembly, and optimization of an RF plasma process to promote in-plane fusion of the nanoparticles to form porous, electrocatalytically active and electrically conductive membranes. This thesis consists of seven chapters. The first chapter provides an introduction into the topic of PEMFCs, some perspective on the current status of research and development of PEMFCs, and an outline of the thesis. The second chapter provides an overview on the methods used, characterization techniques employed and protocols followed for sample preparation. The third chapter describes the modelling of a PEMFC using the Kinetic theory of gases to arrive at an estimate of the maximum feasible current density, based on the kinetics of the electrocatalytic reactions. The fourth chapter presents the development of a simple protocol for synthesizing Au@Pt nanoparticles with control over platinum shell thicknesses from the sub monolayer coverage onwards. The results of spectroscopic and microscopic characterization establish the uniformity of coating and the absence of secondary nucleation. Chapter five describes the formation of a nanoporous, electrocatalytically active membrane by self-assembly to form bilayers of 2D arrays of Au@Pt nanoparticles and subsequent fusion using an RF plasma based process. The evolution of the electrocatalytic activity and electrical conductivity as a function of the duration of RF plasma treatment is monitored for Au@Pt nanoparticles with various extent of platinum coating. Spectroscopic, microscopic, electrical and cyclic voltammetry characterization of the samples at various stages were used to understand the structural evolution with RF plasma treatment duration and discussed. Next durability studies were carried out on the nanoporous, Au@Pt bilayer nanoparticle array with an optimum composition of Pt/Au atomic ratio of 0.88 treated to 16 minutes of argon plasma exposure. After this the novel catalyst membrane design of PEM fuel cell is revisited. Two different techniques are proposed so that the thin, nanoporous, metallic catalyst membrane achieves horizontal electronic resistance equivalent to that of the conventional gas diffusion layer with catalyst layer. The first technique proposes the introduction of gold coated polymeric mesh in between the thin, nanoporous, metallic catalyst membrane and bipolar plate and discusses the advantages. Later the gold coated polymeric mesh is introduced in a conventional membrane electrode assembly and efficiency of the polarization curves probed with and without the introduction of gold coated polymeric mesh. The second technique describes the results of fabrication of a nanoporous metallic membrane using multiple layers of 2D Au@Pt nanoparticle arrays at an optimum composition of Pt/Au atomic ratio of 0.88 to reduce the horizontal electronic resistance. Preliminary studies on the permeability of water through such membranes supported on a porous polycarbonate filter membrane are also presented. In chapter six, a simple reactive inkjet printing process for fabricating SERS active silver nanostructures on paper is presented. The process adapts a simple room temperature protocol, using tannic acid as the reducing agent, developed earlier in our group to fabricate porous silver nanostructures on paper using a commercial office inkjet printer. The results of SERS characterization, spectroscopic and microscopic characterizations of the samples and the comparison of the substrate’s long-term performance with respect to a substrate fabricated using sodium borohydride as the reducing agent is discussed. Preliminary findings on attempts to fabricate a conductive silver network using RF plasma induced fusion area also presented. Chapter seven provides a summary of the results, draws conclusions and a perspective on work required to accomplish the goals of incorporating the porous metallic nanostructures into PEMFCs.