SONIA REGINA HOMEM DE MELLO CASTANHO

SONIA REGINA HOMEM DE MELLO CASTANHO

(Fonte: Lattes)

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Graduada em Engenharia de Materiais (UFSCar, Universidade Federal de São Carlos), Mestre em Tecnologia Nuclear (IPEN/USP, Universidade de São Paulo) e Doutora em Ciências Químicas-Cerâmicos (UAM/ES -ICV/CSIC, Universidad Autónoma de Madrid, Espanha e Instituto de Ceramica y Vidrio/CSIC de Espanha). Ela é Pesquisadora Senior e atualmente Gestora Adjunta em Pesquisa e Desenvolvimento do Centro de Ciências e Tecnologia de Materiais (CCTM) do Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). É Professora da Universidade de São Paulo (USP), no programa de posgraduação Tecnologia Nuclear - Materiais. Coordenadora do grupo de pesquisas (GP/CNPq) em Materiais e Meio Ambiente. Principais áreas de atuação: - Energias Renováveis (células a combustível, catalizadores e biomassa), - Ambiental (mitigação, inertização e requalificação de efluentes e subprodutos de processos extrativistas e industriais, diretivas ambientais (RhOS, WEEE)), - Cerâmicas Biocompatíveis (vidros, compósitos multifuncionais para a implantologia). Experiência em gestão de Centro de Pesquisas, gestão ambiental, gestão de projetos, planejamento composicional de materiais, processamento coloidal, reologia, vidros e vitroceramicos, compósitos multifuncionais e nanoestruturas naturais. (Texto extraído do Currículo Lattes em 27 dez. 2021)

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High chemical stability of stoneware tiles containing waste metals
2010 - REINOSA, J.J.; SILVA, A.C.; RUBIO-MARCOS, F.; MELLO CASTANHO, S.R.H.; MOYA, J.S.; FERNANDEZ, J.F.
Stoneware tiles were produced by the incorporation of galvanic waste to industrial compositions that were processed from kaolinitic clay, feldspar, quartz and recycled domestic glass. The galvanic waste required a calcination step to eliminate the gas forming species prior to its incorporation into industrial processes and crystalline phases were formed. After that, the effective incorporation of metals from the galvanic waste was attained through the formation and the refinement of crystalline phases that acted as pigments. During the fast firing the calcined galvanic waste only got partially dissolved in the liquid phase that developed in spinel phase nanocrystals. The followed procedure allowed to effective immobilization of up to 10 wt% of waste with heavy metals in a porcelain stoneware that satisfy both the mechanical and the chemical standards required to massively commercialize such a product
Yttria nettings by colloidal processing
2014 - SANTOS, S.C.; ACCHAR, W.; YAMAGATA, C.; MELLO CASTANHO, S.
Vitrified galvanic waste chemical stability
2007 - SILVA, A.C.; CASTANHO, S.R.H.M.
Tape casting of strontium and cobalt doped lanthanum chromite suspensions
2010 - SETZ, LUIZ F.G.; SANTACRUZ, ISABEL; COLOMER, M.T.; MELLO CASTANHO, SONIA R.H.; MORENO, RODRIGO
Lanthanum chromite (LaCrO3) is currently the most widely studied material as interconnector layers for solid oxide fuel cells (SOFC). The complexity of microstructures and geometries of SOFC devices, which are usually built-up by lamination of the different constitutive layers, make it necessary a precise control of processing parameters to achieve the desired combination of properties. Much effort has been devoted to the processing of electrodes and electrolytes but the other layers, such as that of interconnecting material, have received scarce attention. This work deals with the preparation and optimisation of the rheological behaviour of concentrated suspensions of Sr- and Co-doped LaCrO3 and the subsequent tape casting to produce homogeneous thin sheets to be used in the SOFC stack. The starting powder was produced by combustion synthesis from the corresponding nitrates and urea as a fuel, and had a final composition of La0.80Sr0.20Cr0.92Co0.08O3. These powders were dispersed in ethanol with commercial copolymers (Hypermer, KD6) to solids loading of up to 58wt%. The binding system (BS) consisted of a mixture of a binder, polyvinyl butyral-co-vinyl alcohol-co-vinyl acetate (PVA-PVAc), and two plasticizers, polyethyleneglycol (PEG400) and benzylbutylphthalate (BBP). The effect of the binding system content and the binder-to-plasticizer ratio on the tape casting performance and the characteristics of the green and the sintered tapes, were studied, as well as the influence of the casting parameters (casting speed and blades height).
Microstructure design by mechanical alloying
2010 - RESTIVO, THOMAZ A.G.; MELLO CASTANHO, SONIA R.H.
Mixing and coprecipitation processes are, often, not enough in order to reach materials holding several functional components, like selective catalysts that must work simultaneously. Even though when a homogeneous and fine distribution of the constituents is obtained, the affinity between equal phase particles leads to coarsening during the consolidation (sintering) process, as well as on application, such as the material can loose high reactivity. The present work proposes a new consolidation route – sintering by activated surface (SAS) – that employs sacrificial metal layers to avoid coarsening and to increase the diffusion profiles during sintering, once high activity surfaces are exposed during the first sintering step. Regarding limited oxygen potential is established in the sintering atmosphere, the SAS effect is engaged when a specific projected powder microstructure obtained by mechanical alloying (MA) processing is provided. The MA is driven in such a way that yields cermet powders particles with lamellar pod-like like structures, as shown in the SEM image. This projected morphology comprises the ceramic round particles plated by thin metal layers or embedded on them. Porous nickel–zirconia based cermets are studied with Cu and some selected refractory metal additives. The refractory metals are expected to repeal Cu, which remains in pure state at the cermet. By its turn, Cu addition is postulated to prevent coking when fuel-reforming reactions are involved at the application (e.g. in solid oxide fuel cells). Furthermore, Cu is desired since it promotes shrinkage and lower the sintering temperatures. The SAS process running under argon atmospheres with controlled oxygen partial pressure is found to further reduce the sintering temperature by 100–300 ◦C, for cermets final densities above 60%TD. The sintering behaviour depends on the chosen additive, being Ag, Cu and Mo the most effective ones. The resulted sintered parts attain a suitable density and phase dispersion for catalysis applications.
A viscoelastic approach from 'alfa'-Alsub(2)Osub(3) suspensions with high solids content
2013 - SETZ, LUIZ F.G.; SILVA, ANTONIO C.; SANTOS, SILAS C.; MELLO CASTANHO, SONIA R.H.; MORELLI, MARCIO R.