SOLANGE KAZUMI SAKATA

SOLANGE KAZUMI SAKATA

(Fonte: Lattes)

Resumo

Possui graduação em Química bacharelado e licenciatura pela Universidade de São Paulo. Doutorado na área de Química Orgânica, com ênfase em Eletrossintese Orgânica pelo Instituto de Química da Universidade de São Paulo. Pós - doutorados em Biotecnologia no Scripps Institution of Oceanography na University of California - San Diego -USA) e no Instituto de Química da Universidade de São Paulo. Foi pesquisadora visitante no Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB-Stuttgart - Alemanha no estudo do metagenoma na produção de enzimas para fins catalíticos e no Centro Tecnológico da Marinha de São Paulo (CTM-SP) no desenvolvimento e caracterização de polímeros. Atualmente é pesquisadora do Instituto de Pesquisas Energéticas e Nucleares (IPEN- SP / CNEN) no Centro de Tecnologia das Radiações e estuda o efeitos das radiações em nano materiais de carbono. (Texto extraído do Currículo Lattes em 27 dez. 2021).

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Low-temperature reduction of graphene oxide using the HDDR process for electrochemical supercapacitor applications
2020 - BENITEZ JARA, F.G.; CRUZ, P.D.V.; BARBOSA, L.P.; CASINI, J.C.S.; SAKATA, S.K.; PERUZZI, A.J.; FARIA, R.N.
In the present work, attempts of reducing a graphene oxide powder using a low temperature hydrogenation disproportionation desorption and the recombination process (L-HDDR) has been carried out. A lower processing temperature in large scale production is significant when costs are concerned. Graphite oxide was prepared using a modified Hummers’ method dispersed in ethanol and exfoliated using ultrasonication to produce Graphene Oxide (GO). Investigations have been carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results of L-HDDR processing graphene oxide powder, using unmixed hydrogen at 400°C and relatively low pressures (<2 bars) have been reported. X-ray diffraction patterns showed a reduction of graphene oxide with the L-HDDR process. The results showed that both processes, the L-HDDR as well as the standard HDDR, may be applied to the reduction of graphene oxide in order to produce supercapacitor materials. The advantage of employing the L-HDDR process is a relatively low temperature reducing the cost of treatment, what is a very important factor for producing a large amount of material. Thus, the L-HDDR process has been considered a promising alternative method of reducing graphene oxide with efficiency, with the possibility of large scale production.
X-ray diffraction evaluation of the average number of layers in thermal reduced graphene powder for supercapacitor nanomaterial
2019 - CARDOSO, QUEZIA de A.; CASINI, JULIO C.S.; BARBOSA, LUZINETE P.; SERNA, MARILENE M.; GALEGO, EGUIBERTO; SOBRINHO, LUIZA F.; SAKATA, SOLANGE K.; FARIA JUNIOR, RUBENS N. de
Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. In this work, the thermal reduction of GO powder has been carried out using back pumping vacuum pressures and investigated employing X-ray diffraction analysis. The experimental results of estimating the number of graphene layers on the reduced powder at various temperatures (200 – 1000 °C) have been reported. Electrical changes have been produced in a graphene oxide with the vacuum reduction process. This study has shown that the ideal processing temperature for reducing graphene oxide nanomaterial was about 400 oC. It has also been shown that at 600 oC the number of layers in the reduced nanomaterial increased. The internal series equivalent resistance (ESR) has been improved substantially with the vacuum thermal treatment even at temperatures above 400 oC. ESR was reduced from 95.0 to about 13.8 Ω cm2 with this processing. These results showed that the process can be applied to the reduction of graphene oxide to produce supercapacitor nanomaterials. The advantage of employing this method is that the processing is a straightforward and low cost thermal treatment that might be used for large amount of nanocomposite material.
The production of reduced graphene oxide by a low-cost vacuum system for supercapacitor applications
2018 - CARDOSO, QUEZIA; SILVA, FRANKS M.; VIEIRA, LIGIA S.; CASINI, JULIO C.S.; SAKATA, SOLANGE K.; FARIA, RUBENS N. de
Graphene has attracted significant interest because of its excellent electrical properties. However, a practical method for producing graphene on a large scale is yet to be developed. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygencontaining groups and recovering the conjugated structure. GO can be produced using inexpensive graphite as the raw material via cost-effective chemical methods. High vacuum and temperature (10−7 mbar and 1100°C, respectively) conditions are well-known to enable the preparation of reduced powder at the laboratory scale. However, a large-scale high vacuum reduction system that can be routinely operated at 10−7 mbar requires considerable initial capital as well as substantial operational and maintenance costs. The current study aims at developing an inexpensive method for the large-scale reduction of graphene oxide. A stainless steel vessel was evacuated to backing-pump pressure (10−2 mbar) and used to process GO at a range of temperatures. The reduction of GO powder at low vacuum pressures was attempted and investigated by X-ray diffraction and Fourier transform infrared spectroscopy. The experimental results of processing GO powder at various temperatures (200–1000°C) at relatively low pressures are reported. The microstructures of the processed materials were investigated using scanning electron microscopy and chemical microanalyses via energy dispersive X-ray analysis.
Supercapacitor application of powder prepared using the Hydrogenation Disproportionation Desorption and Recombination (HDDR) process in graphene oxide
2017 - CASINI, JULIO C.S.; FERNANDEZ, ANTONIO P.R.; OLIVEIRA, RENE R. de; SAKATA, SOLANGE K.; FARIA JUNIOR, RUBENS N.
Graphene (G) has been attracted great interest for its excellent electrical properties. However, the large-scale production of graphene is presently unfeasible. Graphene oxide (GO) can be (partly) reduced to graphene-like sheets by removing the oxygen-containing groups with the recovery of a conjugated structure. It can be produced using inexpensive graphite as raw material by cost-effective chemical methods. Although hydrogen (mixed with argon) at high temperature (1100°C) has been employed to reduce GO powder, the hydrogenation disproportionation desorption and recombination (HDDR) process in particular was unreported for this purpose. In the present work, attempts of reducing GO powder using the HDDR process have been carried out and investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). The experimental results of processing graphene oxide powder using unmixed hydrogen at moderate temperatures (about 850°C) and relatively low pressures (<2 bars) have been reported.