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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Low-temperature densification of ceramics and cermets by the intermediary stage activated sintering method
2018 - RESTIVO, THOMAZ A.G.; DURAZZO, MICHELANGELO; MELLO-CASTANHO, SONIA R.H. de; MOREIRA, ANA C.; GRACIANO, SERGIO; TELLES, VICTOR B.; TENORIO, JORGE A.S.
The article explores new concepts in order to promote ceramic and cermet materials sintering at lower temperatures between 1200 and 1300 C. The principle of the new process method called intermediary stage activated sintering (ISAS) involves the preparation of the ceramic powder with dispersed doping agents, such as nanotubes and fibers, which shape the pore structure at pressed pellets with stable interconnected thin cylinders between the grains. This feature resembles and extends the condition found during the intermediary stage sintering, which enhances the ions diffusion rate along tubular pores to increase shrinkage. Carbon nanotubes (CNT) and nanofibers are homogenized into cubic zirconia and alumina in amounts ranging from 1 to 10 vol% at high-energy milling devices and ultrasound disruptor under ethanol media. Ni, Cu and Mo/MoO3 can be also added to provide tubular channel filling. Sintering of uniaxially pressed pellets is carried out in a dilatometer and tubular furnaces at 1200/1300 C under air, argon and controlled oxygen partial pressure atmospheres. TG/DTA/MS analyses of sample pellets reveal the oxidation and gas release temperature and duration. The results demonstrate the ISAS process concept is valid since it further increases the ceramic final density by 8% of the theoretical density at 1200 C, leading to close the porosity at 1300 C, compared to 1500–1600 C temperatures at conventional process. Short CNT and cellulose nanofiber were found to be the best additives in this sense.
Processing, microstructure and thermoluminescence response of biomorphic yttrium oxide ceramics
2016 - SANTOS, S.C.; YAMAGATA, C.; CAMPOS, L.L.; MELLO-CASTANHO, S.R.H.
The present work reports a fast-direct bio-prototyping process using Luffa Cylindrica vegetable sponge to produce biomorphic yttrium oxide ceramics with reticulated-porous architecture and thermoluminescence response. Processing parameters as rheology of yttrium oxide suspensions, bio-template surface treatment and thermal decomposition of bio-template were investigated. Shear thinning suspensions of 30 vol% yttrium oxide with apparent viscosity of 243mPa.s provided a successful impregnation of samples, whereby bio-templates with smooth ceramic layer and hierarchical reticulated architecture were formed. By thermal treatment at 1600 degrees C for 2 h biomorphic yttrium oxide ceramics with porous microstructure and TL response at 150 degrees C and lambda=550 nm were produced. The proposed fast direct bio-prototyping process is suitable for the production of ceramic components with complex shape and demonstrates potential for general applicability to any bio-template. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Biocide glass based on Nb2O5-SiO-CaO-Na2O system
2016 - SANTOS, FELIPE A.; SILVA, ANTONIO C.; SANTOS, CLAUDINEI; SIMBA, BRUNO G.; BARTOLOME, JOSE F.; DURAN, TERESA; FERNANDEZ-GARCIA, ELISA; ROGERO, SIZUE O.; MELLO-CASTANHO, SONIA R.H.
In this work,glasses based on SiO-CaO-Na2O system containing different Nb2O5 contents were developed. Glasses were melted at 1500 °C and quenched in a metallic mould. Citotoxicity tests were performed using neutral red uptake methodology and indicated normal cell growth, which enables the use as biomaterial. Biocide activity was evaluated through glass incubation in bacterial suspension (Escherichia coli) at 37 °C under shaking. The composition with higher content of SiO2 and lower content of Nb2O5 presented higher biocide activity and the coefficient of thermal expansion indicate thermal compatibility with stainless steel 316L and titanium alloys.
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
Processing and thermoluminescent response of porous biomorphic dysprosium doped yttrium disilicate burner
2016 - SANTOS, S.C.; YAMAGATA, C.; CAMPOS, L.L.; MELLO CASTANHO, S.R.H.
Strontium and cobalt doped-lanthanum chromite
2015 - SETZ, L.F.G.; SANTACRUZ, I.; LEON-REINA, L.; TORRE, A.G. De la; ARANDA, M.A.G.; MELLO CASTANHO, S.R.H.; MORENO, R.; COLOMER, M.T.
Perovskite powders prepared by combustion synthesis with a nominal composition of La0.800Sr0.200Cr0.920Co0.080O3.000 δ were obtained from the corresponding metal nitrates, and characterised in terms of in-situ phase development (crystalline structure and thermal behaviour). Synchrotron X-ray powder diffraction (SXRPD) and Rietveld analyses demonstrated that the as-prepared powder showed an orthorhombic perovskite structure with an estimated composition of La0.803Sr0.197Cr0.966Co0.034O3.000 δ. Second phases present in the as-prepared powder were m-LaCrO4, CoLa1.250Sr0.750O4.000, c-CoCr2.000O4.000 and m-SrCrO4.000. Sintering processes, including phase transition (from orthorhombic to rhombohedral) of the main phase and, melting/evaporation of second phases have been studied by DTA/TGA and dilatometric studies; the results were in full agreement with those detected by High-Temperature Synchrotron X-ray powder diffraction (HT-SXRPD). The transition temperature was determined to be 1380 1C by dilatometric studies, and between 1240 and 1405 1C by HT-SXRPD. Dye-pressed samples sintered at 1600 1C/4 h showed a density of 98.9 dth%. The phase transition is an irreversible process since the sintered perovskite, measured at room temperature after cooling, only showed the rhombohedral phase as main phase. The evaluation of the linearity of the conductivity versus the inverse of temperature and the activation energy values of the sintered material indicated that the electrical conduction occurs via the non-adiabatic small-polaron mechanism in either air or hydrogen atmosphere. In the reducing environment, the perovskite shows significantly reduced electrical conductivity compared with that in air, as it is expected for a p-type conductor. & 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
TG/DTA-MS evaluation of methane cracking and coking on doped nickel-zirconia based cermets
2014 - RESTIVO, THOMAZ A.G.; MELLO CASTANHO, SONIA R.H.; TENORIO, JORGE A.
Cermet materials based on metallic nickel and cubic zirconia are the key material for applications on solid oxide fuel cells and high temperature water electrolysis. The main advantage is the possibility of direct feeding a hydrocarbon fuel, like methane, or even an alcohol as a source of hydrogen. The reforming reaction on the Ni catalyst surface can produce hydrogen continuously. However, the resulting catalyst poisoning by carbon deposition (coking) imparts their broad application. The work shows the evaluation of coking tolerance of some cermets prepared by mechanical alloying techniques and compares new additives specially chosen in order to avoid coking and increase the catalytic activity. Refractory metal additives besides copper were added to the basic cermet. While copper is a known doping agent that avoids coking, the refractory metals (Mo and W) have a twofold effect: promote sintering at lower temperatures and increase Cu activity due to their mutual immiscibility. Results of TG/DTA-MS analysis demonstrate both refractory metals have increased the coking tolerance as well as the catalytic activity during diluted methane cracking. Molybdenum and tungsten additives are promised regarding the improvement of these cermet materials for high temperature electrochemical devices.
High barium content lead and alkaline-free glasses
2014 - SILVA, MAVIAEL J. da; MOYA, JOSE S.; PECHARROMAN, CARLOS; SANZ, JESUS; MELLO CASTANHO, SONIA
Yttria nettings by colloidal processing
2014 - SANTOS, S.C.; ACCHAR, W.; YAMAGATA, C.; MELLO CASTANHO, S.
Kinetics of dissolution of a biocide soda-lime glass powder containing silver nanoparticles
2013 - ESTEBAN TAJEDA, L.; SILVA, A.C. da; MELLO CASTANHO, S.R.; PACHARROMAN, C.; MOYA, J.S.