Nanostructured Particles
Mostrando 13-24 de 35 artigos, teses e dissertações.
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13. Síntese de óxido de zinco nanoestruturado por combustão em solução e caracterização de propriedades microestruturais e atividade fotocatalítica
Materiais nanoestruturados são caracterizados por terem tamanho de cristalito inferior a 100 nm e apresentarem propriedades diferenciadas em relação aos materiais convencionais. A intensificação da nanotecnologia como uma área de pesquisa vem gerando grandes expectativas na ciência de materiais, tendo em vista a vasta gama de novas propriedades físic
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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14. Obtenção de ZnO nanoestruturado e caracterização de propriedades e atividade fotocatalítica
Este trabalho versou sobre a obtenção de partículas nanoestruturadas de ZnO pela técnica de evaporação térmica a partir de zinco metálico. Basicamente, a síntese ocorria em um reator de quatzo colocado em um forno tipo mufla, onde o zinco metálico reagia com uma atmosfera oxidante, proporcionada pela injeção de ar comprimido. Inicialmente, o forn
Publicado em: 2011
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15. Materiais nanoestruturados baseados em Pt e Sn para células a combustível de etanol direto / Nanostructured materials based on Pt and Sn for Direct Ethanol Fuel Cells
This work presents the synthesis, characterization and performance of different electrocatalysts for Direct Ethanol Fuel Cells (DEFC). As cathode applications in DEFC it was synthesized a Pt3Sn/C alloy (20% metal w/w on carbon) by the polymeric precursor method (PPM) with 90% of alloy degree and particle sizes lower than 10%. Its performance using Pt3Sn/C as
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/09/2010
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16. Implantação iônica de baixa energia em polímero para desenvolvimento de camadas compósitas nanoestruturadas condutoras litografáveis. / Low energy ion implantation into polymers to develop conductive composite layers for lithography.
Electronics using polymers instead of silicon is a recent research area with promising economic perspectives. Polymer with metallic particles composites presents interesting electrical, magnetic and optical properties and they have been produced by a broad variety of techniques. Metal ion implantation using plasma is one of the used methods to obtain conduct
Publicado em: 2010
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17. Processamento e estudo de ortoniobatos de terras raras e ortotungstatos de metais alcalinos terrosos
Two classes of orthoceramic compounds of general formula ABO4 were investigated in this work. The first group includes the lanthanide orthoniobates (RENbO4, RE = La-Lu, except Pm), which were synthesized by conventional solid-state route at 1150C in different conditions of time aiming the production of crystalline, single phase materials. Alkaline- earth-met
Publicado em: 2010
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18. Synthesis of nanostructured boron nitride and its potentially for application in cosmetology / Sínteses e caracterização de nitreto de boro nanoestrutrado com potencialidade de aplicação em cosmetologia
Regular use of appropriate cosmetics is an important resource for the maintenance of the skin health and, consequently, its beauty. The effect of ultraviolet rays is harmful to the health of the skin and can result in increase of the cancer incidence, aging and other undesirable cutaneous changes. The effects of the infra-red rays are less described in the s
Publicado em: 2009
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19. Microscopical study of nanometric particles adhesion / Estudo microscopico de adesão de particulas nanometricas
The adhesion of nanometric phases is a topic of increasing scientific interest due to its importance for the production and properties of new nanostructured materials. This study explores the following hypothesis: immiscible and wettable particles carrying charges with same signal can adhere provided that they are mixed in aqueous dispersion and dried out. T
Publicado em: 2009
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20. Sintese de materiais nanoestruturados MS IND. 2 (M = Mo, W) com alta pureza de fase e morfologia / Synthesis of MS IND. 2 (M = Mo, W) nanostructured materials with high purity of phase and morphology
The main of this Dissertation is the preparation of nanostructured WS2 and MoS2 from a template reaction with the respective nanorods oxides. Molybdenum oxide nanorods with diameters around 100 nm and microscale lengths were prepared from MoO3·2H2O via a one step solvothermal reaction. The formation of MoO3 rods proceeds in acidic media at 180 °C. The oxid
Publicado em: 2008
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21. Synthesis of TIO2 colloidal nanocrystals by solvothermal method / Síntese de nanocristais coloidais de TiO2 via método solvotermal
This work presents a systematic study about preparing titanium oxide nanoparticles by solvothermal method. TiO2 is a much studied material because its applications in areas like catalysis, sensors, energy conversion devices, and others. It is speculated that all this technologies can be promoted by using nanostructured oxide. In order to confirm this, it is
Publicado em: 2008
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22. Análise do efeito do tempo da moagem de alta energia no tamanho de cristalito e microdeformação da rede cristalina do WC-Co
Hard metals are the composite developed in 1923 by Karl Schröter, with wide application because high hardness, wear resistance and toughness. It is compound by a brittle phase WC and a ductile phase Co. Mechanical properties of hardmetals are strongly dependent on the microstructure of the WCCo, and additionally affected by the microstructure of WC powders
Publicado em: 2008
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23. Estudo de rotas alternativas para a fabricação de ímãs compósitos à base de Sm2Fe17N3
This monograph thesis concerns the study of alternative processing routes regarding the fabrication of permanent magnets based on the Sm2Fe17N3 intermetallic compound. The study is mainly based on the compound synthesis in powder form and its subsequently shaping to get the final magnet body. Instead of the traditional induction melting of metallic samarium
Publicado em: 2008
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24. Processamento e caracterização física e mecânica de cerâmicas de zircônia-ítria total e parcialmente nanoestruturadas / Physical and mechanical characterization of total and partially nanostructured zirconia-yttria ceramics
In this work the behavior of nanostructured and partially nanostructured zirconia-yttria ceramics is analyzed during the compacting and sintering processes. The evaluation of the mechanical properties (flexure strength, fracture toughness and hardness) also is presented. They were studied two groups: one composed by a microparticulate powder obtained through
Publicado em: 2007