DEMAT - Departamento de Engenharia de Materiais
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Article One-step synthesis and microstructure of CuO-SDC composites(FapUNIFESP (SciELO), 2017-03) Nascimento, Rubens Maribondo do; Firmino, Hellen Cristina Torrano; Araújo, A. J. M.; Dutra, Ricardo P. S.; Rajesh, Surendran; Macedo, Daniel Araújo deUma rota de síntese em uma etapa baseada no método dos precursores poliméricos foi usada para produzir pós do nanocompósito contendo as fases CuO e céria dopada com samária (SDC). Esta rota química permitiu obter pós compósitos com reduzido tamanho de partícula e uniforme distribuição dos elementos Cu, Ce e Sm. O material particulado foi caracterizado por difração de raios X (DRX) combinado com refinamento Rietveld dos dados de difração. Compósitos CuO-SDC sinterizados em ar entre 950 e 1050 °C e em seguida reduzidos a Cu-SDC foram caracterizados por DRX e microscopia eletrônica de varredura. A porosidade aberta foi medida usando o princípio de Arquimedes. Microestruturas adequadas para os processos de transferência de carga e transporte de massa (30 a 45% de porosidade) foram obtidas em cermets Cu-SDC previamente sinterizados a 1000 a 1050 °C. Os resultados indicaram que compósitos CuO-SDC e cermets Cu-SDC com potencial aplicação como anodos de células a combustível de óxido sólido (CCOS) podem ser obtidos por projeto microestrutural. Meia célula suportada no anodo foi preparada por coprensagem e cossinterização de céria dopada com gadolínia (CGO) e o nanocompósito obtido neste trabalhoArticle Nanocompósitos de PEAD/PEBDL: avaliação da esfoliação da argila organofílica pela aplicação do modelo de Nielsen e das propriedades mecânicas, ópticas e permeabilidade(FapUNIFESP (SciELO), 2010-02) Ito, Edson Noriyuki; Morales, Ana R.; Cruz, Carolina V. M. da; Peres, LeilaA typical high density polyethylene and linear low density polyethylene (HDPE/LLDPE) blend used in flexible packaging was modified with commercial organophylic montmorilonite clay to obtain nanocomposites with superior barrier properties. Samples with 5 and 7.5% of clay were prepared under different processing conditions. Films produced from the nanocomposites were evaluated in terms of oxygen and water vapor permeation and also by X-ray diffraction and Transmission Electron Microscopy. Tensile and optical properties were also evaluated. The clay showed to be intercalated and partially exfoliated. The oxygen permeation was mainly reduced and the vapor permeation was weakly modified. The mechanical properties and transparency did not change significantly. Nielsen's model was applied considering the relative permeability coefficient. This method was able to give an estimate of the exfoliation state of the samples, supported by the transmission electron microscopyArticle Nanocomposites of poly(methyl methacrylate) (PMMA) and montmorillonite (MMT) Brazilian clay: A tribological study(Express Polymer Letters, 2010-08) Ito, Edson Noriyuki; Brostow, Witold; Dutta, M.; Souza, J. Ricardo de; Rusek, P.; Medeiros, Antonio Marcos deArticle Polyamide 66/Brazilian clay nanocomposites(Hindawi Publishing Corporation, 2009) Ito, Edson Noriyuki; Araújo, Edcleide Maria; Araújo, K. D.; Paz, Renê Anísio; Gouveia, R.; Barbosa, R.Article Structure and mechanical properties of polyamide 6/ Brazilian clay nanocomposites(FapUNIFESP (SciELO), 2009-06) Ito, Edson Noriyuki; Leite, Amanda Melissa Damião; Araujo, Edcleide Maria; Paz, Rene Anisio da; Pereira, Osanildo Damião; Lira, Hélio LucenaArticle Obtenção de membranas microporosas a partir de nanocompósitos de poliamida 6/argila nacional. Parte 1: influência da presença da argila na morfologia das membranas(ABM, ABC, ABPol, 2009) Ito, Edson Noriyuki; Leite, Amanda Melissa Damião; Araújo, Edcleide Maria; Barbosa, Renata; Lira, Hélio de LucenaPolymeric membranes were produced from nylon 6 nanocomposites and a clay using the immersion-precipitation technique. The clay was organically modified by using a quaternary ammonium salt, Dodigen. Nanocomposites were obtained from nylon 6 with untreated clay (MMT) and treated clay (OMMT). The nanocomposites were studied by XRD and TEM. The morphological structure consisted of an exfoliated and partially exfoliated clay layers in the polymeric matrix. The membranes were produced by phase inversion method and characterized by XRD and SEM. The X-ray diffraction of the membranes confirmed the results for the nanocomposites. The SEM image of the membrane top surface showed irregular pores. As for the membranes with the nanocomposites, a larger number of better distributed pores were observed, indicating that the presence of the clay altered the membrane morphology. The cross section SEM image showed an asymmetric morphology structure, comprising two layers, namely a skin with small and closed pores, and a porous layer with large, uniformly distributed poresArticle Nanocompósitos de polietileno/argila bentonita nacional: influência da argila e do agente compatibilizante PE-g-MA nas propriedades mecânicas e de inflamabilidade(Associação Brasileira de Polímeros, 2008-06) Ito, Edson Noriyuki; Brito, Gustavo F.; Oliveira, Amanda D. de; Araújo, Edcleide Maria; Melo, Tomas Jeferson Alves; Barbosa, RenataHigh density polyethylene/national bentonite clay nanocomposites were prepared with the melt intercalation technique. The effect of the clay without treatment and clay treated with quaternary ammonium salt Cetremide with polyethylene-graft-maleic anhydride as coupling agent was evaluated. The systems were characterized by flammability, mechanical and rheological properties, X ray diffraction and transmission electron microscopy. In general, the results of X ray diffraction and transmission electron microscopy showed partially exfoliated and/or intercalated structures with higher tensile modulus and torque value. The flammability test showed that the addition of clay in the polymer matrix and PE-g-MA reduced the burning rate, indicating an improved flammability resistance of the nanocomposites. In general, the system containing PE-g-MA coupling agent led to partially exfoliated nanocomposites with higher thermal stability than the high density polyethylene matrix. The polyethylene-graft-maleic anhydride promoted the exfoliation of clay and adhesion between matrix and filler, thus resulting in enhanced mechanical propertiesArticle High energy mill processing of polymer based nanocomposites(SAGE Publications, 2008-08-07) Melo, José Daniel Diniz; Almeida, Cláudio Romero Rodrigues de; Paskocimas, Carlos Alberto; Mendonça, Rannier Marques; Medeiros, Antonio M.Article TiO2/PDMS nanocomposites for use on self-cleaning surfaces(Elsevier, 2014-01-25) Tavares, Marileide L.A.; Santos, Amélia S.F.; Santos, Ieda Maria Garcia dos; Silva, Manoel Rincón S.; Delmonte, Maurício Roberto Bomio; Silva, Elson Longo da; Paskocimas, Carlos Alberto; Motta, Fabiana Villela da