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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Fast, efficient and clean adsorption of bisphenol-A using renewable mesoporous silica nanoparticles from sugarcane waste ash
2020 - ROVANI, SUZIMARA; SANTOS, JONNATAN J.; GUILHEN, SABINE N.; CORIO, PAOLA; FUNGARO, DENISE A.
Even with all the biological problems associated with bisphenol-A (BPA), this chemical is still being widely used, especially in thermal paper receipts. In this study, renewable mesoporous silica nanoparticles (MSN), obtained from sugarcane ash, functionalized with hexadecyltrimethylammonium (CTAB) were applied as an adsorbent in the removal of BPA from the aqueous solution. The versatility of this material and its BPA adsorption capacity were tested at different pH values, being practically constant at pH between 4 and 9, with a slight increase in pH 10 and a greater increase in pH 11. The removal time evaluation indicates a very fast adsorption process, removing almost 90% of BPA in the first 20 min of contact. The kinetic model indicates a monolayer formation of BPA molecules on the MSN-CTAB surface. The maximum adsorption capacity (Qmax) was 155.78 mg g-1, one of the highest found in literature, and the highest for material from a renewable source.
Pyrolytic temperature evaluation of macauba biochar for uranium adsorption from aqueous solutions
2019 - GUILHEN, S.N.; MASEK, O.; ORTIZ, N.; IZIDORO, J.C.; FUNGARO, D.A.
This study aims to evaluate the effect of the pyrolytic temperature on the biochar derived from the macauba endocarp for the removal of uranium (VI) from aqueous solutions. The endocarp was subjected to six different pyrolytic temperatures, ranging from 250 °C to 750 °C. The biochars obtained at each temperature were evaluated for their adsorption capacities (“q”). The highest adsorption capacities were obtained for the biochar produced at 250 °C (BC250), followed by the one obtained at 350 °C (BC350), with removal efficiencies of 86% and 80%, respectively. The best condition was achieved when the endocarp was subjected to temperatures between 300 and 350 °C, at which it was possible to obtain a satisfactory balance among adsorption capacity, gravimetric yield and fixed carbon content. This characteristic, combined with the high removal efficiency, points to an ideal working temperature of 350 °C. Elemental analysis showed a decrease of the H/C and O/C ratios when higher pyrolytic temperatures were applied, indicating an inverse relationship between the carbonization and the surface polar functional groups, which were likely responsible for an increased adsorptive capacity in biochars produced at lower temperatures. Both FTIR and XPS analysis indicated that oxygen-containing groups such as hydroxyls and carboxylic acids were involved with the binding of uranyl ions.
Improved barium removal and supersaturation depletion in wastewater by precipitation with excess sulfate
2018 - RONQUIM, FLAVIA M.; COTRIM, MARYCEL E.B.; GUILHEN, SABINE N.; BERNARDO, ANDRE; SECKLER, MARCELO M.
Barium ions found in wastewaters cause incrustation on membrane separation equipment used in desalination systems. In this study barium removal by precipitation is addressed, considering excess sulfate addition as a means of reducing barium concentration in solution and depleting BaSO4 supersaturation. Precipitation is conducted with synthetic wastewater in semicontinuous mode. For low excess sulfate, an induction time of a few hours is observed. As the excess sulfate is increased and/or as barium sulfate seeds are added, precipitation proceeds within a few minutes. Besides, the excess sulfate improves barium ion removal due to the common-ion effect. Residual supersaturation ratios were found to lie within the range of 1.1–3. These values were associated with a fourth order dependency of the molecular growth rate with the supersaturation ratio. Calcium carbonate and calcium sulfate dihydrate were found to be ineffective heterogeneous seeds to barium sulfate precipitation. Calcium ions were found to inhibit BaSO4 precipitation, blocking the process at a high residual supersaturation ratio of 4–5. For a sufficiently large initial supersaturation, the solution approaches equilibrium after 180 min.
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