RODRIGO FERNANDO BRAMBILLA DE SOUZA
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Artigo IPEN-doc 29100 Silver nanoparticles-based hydrogels synthetized by ionizing radiation for cleaning of tangible cultural heritage surfaces2022 - OLIVEIRA, MARIA J.A.; OTUBO, LARISSA; PIRES, ADRIANA; BRAMBILLA , RODRIGO F.; CARVALHO, ANA C.; SANTOS, PAULO S.; OLIVEIRA NETO, ALMIR; VASQUEZ, PABLOThe surfaces of the works of art are one of their most important parts since they interact directly with the observer's perception. On the other hand, they are also in direct contact with physical, chemical and biological agents that can induce degradation and signs of aging. Dust deposits, stains and aged layers of protection can degrade, causing irreversible damage to works of art. In this way, the removal of undesirable materials from artistic surfaces is essential to preserve cultural heritage articles. The aim of this work was to develop silver nanoparticles-based hydrogels and to study the behavior regarding solvent concentration, stability and ability to clean dirt samples based on paper and canvas. The hydrogels were synthesized (reticulated) by gamma rays having the simultaneous formation of silver nanoparticles (AgNP) in the same process. The samples were characterized by swelling tests, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, differential scanning calorimetry (DSC), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and optical microscopy (OM). The results showed the removal of dirt from the paper samples, as well as the softening of the dirt from the canvas, without leaving residues and without affecting the integrity of the art works submitted to treatment.Artigo IPEN-doc 29081 Methanol electrosynthesis from CO2 reduction reaction in polymer electrolyte reactors - fuel cell type using [6,6′-(2,2′-bipyridine-6,6′-diyl)bis(1,3,5-triazine-2,4-diamine)] (dinitrate-O) copper (II) complex2022 - GARCIA, L.M.S.; FILHO, N.G.P.; CHAIR, K.; KAUR, P.; RAMOS, A.S.; ZAMBIAZI, P.J.; SOUZA, R.F.B. de; OTUBO, L.; DUONG, A.; NETO, A.O.Electrocatalytic carbon dioxide reduction reaction has been an attractive way to convert greenhouse gas into valuable chemical fuels based on carbon-neutral energy. Therefore, it serves as an effective approach to combating high concentrations of CO2 in the atmosphere as well as reducing the use of fossil fuels responsible for emitting carbon dioxide and other greenhouse gases, meeting growing energy demands. In this work, the copper(II) bis-triazine bipyridine complex supported on carbon black has been applied as a catalyst in a polymeric electrolytic reactor – fuel cell type for converting CO2 into methanol. The physical and nanostructure properties of the Cu(II) nanocomposite were previously determined by Fourier transform infrared, Raman spectroscopy, X-ray powder diffraction, and transmission electron microscopy techniques. The electrocatalytic activity of the Cu complex catalyst was monitory by differential mass spectroscopy. The results indicate that the catalyst is not selective for the preferential synthesis of a specific product, but a mixture of products (methanol, formic acid, formaldehyde, carbon monoxide, and methane) was detected. According to our results, 2.5% and 5% Cu complex on carbon black were the ideal amounts for polymeric electrolytic reactor – fuel cell type applications to produce methanol from CO2 with faradaic efficiency of ∼22% for both compositions.Artigo IPEN-doc 28995 cis-[6-(pyridin-2-yl)-1,3,5-triazine-2,4-diamine](dichloride) palladium(II)-based electrolyte membrane reactors for partial oxidation methane to methanol2022 - GARCIA, LUIS M.S.; ZAMBIAZI, PRISCILLA J.; CHAIR, KHAOULA; DOAN, TUAN D.; RAMOS, ANDREZZA S.; NANDENHA, JULIO; SOUZA, RODRIGO F.B. de; OTUBO, LARISSA; DUONG, ADAM; NETO, ALMIR O.Methane is an abundant resource and the main constituent of natural gas. It can be converted into higher value-added products and as a subproduct of electricity co-generation. The application of polymer electrolyte reactors for the partial oxidation of methane to methanol to co-generate power and chemical products is a topic of great interest for gas and petroleum industries, especially with the use of materials with a lower amount of metals, such as palladium complex. In this study, we investigate the ideal relationship between cis-[6-(pyridin-2-yl)-1,3,5-triazine-2,4-diamine(dichloride)palladium(II)] (Pd-complex) nanostructure and carbon to obtain a stable, conductive, and functional reagent diffusion electrode. The physical and structural properties of the material were analyzed by Fourier transform infrared (FT-IR) and Raman spectroscopies, transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques. The electrocatalytic activity studies revealed that the most active proportion was 20% of Pd-complex supported on carbon (m/m), which was measured with lower values of open-circuit and power density but with higher efficiency in methanol production with reaction rates of r = 4.2 mol L–1·h–1 at 0.05 V.