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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Síntese de pós biocerâmicos dos sistemas CaO-MgO-SiO2 e SiO2-ZrO2 por sol-gel e coprecipitação
2021 - RODRIGUES, VANESSA G.; ERETIDES, GABRIEL T.; RODAS, ANDREA C.D.; CASTANHO, SONIA R.H.M.; YAMAGATA, CHIEKO
Neste trabalho, foram sintetizados pós biocerâmicos dos sistemas CaO-MgO-SiO2 e SiO2-ZrO2 pela combinação das técnicas sol-gel e coprecipitação. Solução Na2SiO3, um efluente de alta pureza gerado no processo de fusão alcalina da zirconita, foi empregada como fonte de SiO2, e soluções clorídricas de Mg e Cl foram utilizadas como precursoras de CaO e MgO. O pó sintetizado de composição molar 43,30% CaO, 10,72% MgO e 45,98% SiO2 apresentou as fases cristalinas wollastonita e diopsita após tratamento térmico a 550 °C por 4h. Cerâmica obtida desta mesma amostra sinterizada a 1200 °C por 2h apresentou bioatividade a partir de 7 dias de imersão em Simulated Body Fluid (SBF) e teste de citotoxicidade mostrou que a amostra não é citotóxica. Para a síntese de pó cerâmico do sistema SiO2-ZrO2 foram utilizadas soluções Na2SiO3 e ZrOCl2 provenientes do processo da fusão alcalina da zirconita como fontes de SiO2 e ZrO2. O pó sintetizado de composição molar (SiO2:ZrO2) (62:38) foi calcinado a 900°C por 3h e a fase tetragonal foi obtida. Cerâmica obtida após sinterização a 1500 °C por 2h foi submetida a teste de bioatividade e citotoxicidade. O produto não apresentou citotoxicidade e até 21 dias de imersão em SBF não apresentou bioatividade.
Editorial
2019 - MELLO-CASTANHO, SONIA R.H.; MORENO, RODRIGO
Micrograded ceramic-metal composites
2019 - RESTIVO, THOMAZ A.G.; BECCARI, RAFAEL F.; PADILHA, WELLINGTON R.; DURAZZO, MICHELANGELO; TELLES, VICTOR B.; COLETI, JORGE; YAMAGATA, CHIEKO; SILVA, ANTONIO C. da; SUZUKI, EDUARDO; TENORIO, JORGE A.S.; MELLO-CASTANHO, SONIA R.H.
The article shows new designed cermets and processes concerning primary to applications as thermal insulation materials with low emissivity. A new projected microstructure was obtained where dense regions (micropellets) rest inside the main porous pellet. The feature resembles a frozen hypercube, therefore such architecture is called hyper-pellet/ cermet. The processing method to obtain the hyper-cermet is based on sequential tape castings and sintering techniques. Ni-zirconia lamellae were prepared by a special mechanochemical process followed by sintering, which remain inside the main pellets as a dense region. The whole pellet is turned to be porous by employing pore-forming additives. All the constituents and porosity shapes are aligned along the disc/ flake planes. Thermal conductivity is estimated for the materials up to 800 °C by a flash diffusivimeter. Ceramographic analyses show graded density regions with directional constituents and pores. Applications of such materials are foreseen as temperature insulation materials and thermal radiation shields.
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.
Yttria nettings by replica processing
2014 - SANTOS, S.C.; YAMAGATA, C.; ACCHAR, W.; MELLO-CASTANHO, S.R.H.
In the context of green economy supported and widespread by United Nations (UN), the renewable energy sources are the unique mechanism to universalize the access to energy. Face to this strategic direction of change is essential to develop efficient components for saving energy such as porous ceramics that associate light with mechanical strength. Thus, the objective of this work concerns to improve the homogeneity of porous size distribution of yttria porous ceramics by evaluating their morphology during replica processing. Samples were subject to immersion into 30vol% yttria aqueous suspensions during an interval from 1min to 120min and sintered through careful thermal conditions. Based on the results, the weight and morphology of porous structure samples were directly influenced by immersion time, whereby intervals from 30-120min showed the best final products.
Fibras de fosfato de cálcio amorfo para regeneração óssea: a bioatividade potencializada pela morfologia
2016 - SILVA, A.C.; ALLEGRINI-JUNIOR, S.; OTTONI, C.; MELLO-CASTANHO, S.R.H.; BRAGA, F.J.C.
Amorphous Calcium Phosphate (ACP) is the first mineral phase formed in hard tissues. ACP has low ordering in the crystal lattice compared to other calcium phosphates. The X-ray diffraction pattern is broad and diffuse with a maximum at 250 (2ϴ), being considered as a precursor of well crystallized hydroxyapatite (HA), reference bone grafting material in odontology and medicine. The ACP graft has high capacity to be resorbable and has been widely studied as a filler for bone defects. However, it is rare to find articles where the ACP is presented in the form of fibers and yet always containing silicon. This research paper presents the ACP fibers obtained by the process Hager-Rosengarth, confirming its amorphous condition by means of X-ray diffraction and its capacity of resorption and ability to conduct and formation of new bone tissue proven by test "in vivo" with subsequent analysis by light microscopy. ACP in the form of fibers is considered innovation as a bone grafting material, having already its exclusive rights of patent claimed by a Brazilian company that is which is being funded by CAPES / FINEP in a program of R & D. Keywords: Fiber, Biomaterials, ACP.
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.
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.
Glass ceramic sealants belonging to BAS (BaO-Alsub(2)Osub(3)-SiOsub(2) ternary system modified with Bsub(2)Osub(3) addition
2016 - SILVA, MAVIAEL J. da; BARTOLOME, JOSE F.; AZA, ANTONIO H. de; MELLO CASTANHO, SONIA
Four compositions in the BaO–Al2O3–SiO2 system modified with B2O3 were investigated with regard to their use as glassy seals in anode supported SOFC or iT-SOFC. The glassy system studied contains varying percentages of SiO2, Al2O3, B2O3, and high content of BaO as modifier (67–74%-wt). Their glass transition (Tg) and maximum densification point lies between 630 and 680 ◦C, and 734 ◦C to 828 ◦C, respectively. The viscosities of the four glasses are situated between 107 to 109.5 Pa.s, in the sealing range (730–830 ◦C). Heat treatment at 850 ◦C, revealed crystalline phases identified as BaAl2Si2O8 (hexacelsian) and BaSiO3. The thermal expansion coefficient (TEC) of the obtained glasses (8.8–10.5 ppm/K) was comparable to zirconia (YSZ) electrolyte, and shows chemical compatibility and high characteristic bond strength (up to 33 ± 7 MPa). The compositions with higher BaO contentin the system studied seem to be good candidates for iT-SOFC sealant application.