SABINE NEUSATZ GUILHEN

SABINE NEUSATZ GUILHEN

(Fonte: Lattes)

Resumo

Possui graduação em Química com atribuições Tecnológicas e Biotecnológicas pelo Instituto de Química da Universidade de São Paulo (2005), mestrado (2009) e doutorado (2018) em Tecnologia Nuclear (Materiais) pelo Instituto de Pesquisas Energéticas e Nucleares (IPEN), Universidade de São Paulo. Tem experiência em Química Analítica com ênfase em Análise de Traços, atuando principalmente no desenvolvimento de métodos analíticos empregando técnicas espectrofotométricas (AAS, ICP OES e ICP-MS) para caracterização de amostras ambientais, arqueológicas, biológicas, forenses e nucleares. Atualmente, ocupa o cargo de Tecnologista em "Caracterização Química" no Centro de Química e Meio Ambiente (CQMA) do IPEN (CNEN/SP), onde desempenha atividades de pesquisa e desenvolvimento tecnológico em atendimento às demandas institucionais ligadas ao Ciclo do Combustível Nuclear e aos Programas de Pesquisa de caráter multidisciplinar, em apoio a projetos de Inovação Tecnológica e ao Programa de Pós-Graduação do IPEN/USP. Além disso, atua na geração de produtos tecnológicos e no desenvolvimento de materiais adsorventes de baixo custo e alto valor agregado visando o aproveitamento de materiais e resíduos naturais e/ou renováveis no tratamento de efluentes e rejeitos. (Texto extraído do Currículo Lattes em 4 maio 2023)

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Effective phosphate removal from water by electrochemically mediated precipitation with coffee grounds biocarbon obtained by non-thermal plasma method
2023 - SILVESTRIN, G.A.; GONCALVES, M.H.; GODOI, C.M.; MAIA, V.A.; FERREIRA, J.C.; GUILHEN, S.N.; NETO, A.O.; SOUZA, R.F.B. de
This study investigates the use of biocarbon electrodes, produced from coffee grounds through plasma pyrolysis, in the electrochemically mediated precipitation process for phosphorus removal in a flow reactor. The structural and electrochemical properties of biocarbon were analyzed using X-ray powder diffraction (XRD), Raman spectroscopy, and cyclic voltammetry. The results show that biocarbon consists of both graphene oxide and lignocellulose with surface OH groups that facilitate the breakdown of water, a key step in the electrochemically mediated precipitation process for phosphorus removal. The addition of graphite to the biocarbon paste was found to be necessary to obtain a response from the biocarbon in cyclic voltammetry. The Gr75BC25 electrode achieved higher phosphorus removal rates than other tested electrodes, particularly at low flows, due to the functional groups present in biocarbon enhancing the breakdown of water. However, electrodes with a greater amount of biocarbon exhibit lower rates of phosphorus removal and higher consumption of electrical power, which can be attributed to their higher electrical resistivity. Thus, to optimize its use, it is important to balance the benefits of increased phosphorus removal rates with the trade-off of increased energy consumption and decreased phosphorus removal at higher levels of biocarbon. The results suggest that biocarbon produced from coffee grounds by plasma pyrolysis has the potential to be used as an effective electrode material for electrochemically mediated precipitation processes.
Evaluation of europium-doped HA/'beta'TCP ratio fluorescence in biphasic calcium phosphate nanocomposites controlled by the pH value during
2016 - SILVA, FLAVIA R.O.; LIMA, NELSON B.; GUILHEN, SABINE N.; COURROL, LILIA C.; BRESSIANI, ANA H.A.
Europium-doped hydroxyapatite (HA), beta-tricalcium phosphate (β-TCP) and biphasic phosphate nanopowders were synthesized by co-precipitation method and their crystal structures and fluorescence properties were investigated depending on the pH of the starting solution. In the range of pH 6–10, HA and β-TCP phases coexist. The β-TCP proportion increased as the pH of the solution decreased, while HA yields decreased. At pH below 6, monophasic β-TCP powder was obtained after thermal treatment. In particular, HA and β-TCP can be used as luminescent materials when activated by Eu3þ ions in substitution of Ca2þ ions. Herein, the Eu3þ ions doped HA and β-TCP phase composition were analyzed in order to investigate the fluorescence emission of the HA, β-TCP and biphasic compounds. Eu-doped HA exhibited a red-orange emission at 575 nm with several minor peaks at 610–640 nm, while Eu-doped β- TCP had an unexpected strong red emission at 610–620 nm and a secondary band at 590–600 nm. In fact, the Eu:β-TCP integrated emission area is almost 20-fold higher than Eu:HA for the same europium ion concentration. These results demonstrate the potential of Eu:β-TCP as biomarker for medical applications, as drug release and targeting based on their luminescent properties