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188 results on '"Biaggio, Sonia R."'

27. Influence of the preparation procedure on the electrochemical properties of Pani(DMcT-Cu ion)/carbon fiber composites

Author

Canobre Sheila C., Biaggio Sonia R., Rocha-Filho Romeu C., and Bocchi Nerilso

Subjects
polyaniline, carbon fiber, DMcT, composites, impedance spectroscopy, Chemistry, QD1-999
Abstract

The electrochemical properties of Pani(DMcT-Cu ion)/carbon fiber composites, obtained by electrochemical means, are analysed as a function of the preparation procedure and the different copper salts (CuCl2.2H2O or CuSO4) used as source of Cu2+ ions to be incorporated into the Pani(DMcT)/carbon fiber composite. The composites were prepared according to two procedures: by adding the copper salt directly to the electrolyte during the polyaniline electrosynthesis (procedure A), or by allowing the copper ion to be physically adsorbed onto the carbon fiber prior to the polymer electroformation (procedure B). The electrochemical stability, electrical properties and morphology of the composites were analysed by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy, respectively.

Published
2003

28. Studies on the stability of anodic oxides on zirconium biocompatible alloys

Author

Oliveira Nilson T. C., Biaggio Sonia R., Rocha-Filho Romeu C., and Bocchi Nerilso

Subjects
zirconium, zirconium alloys, anodic oxides, passivation, Chemistry, QD1-999
Abstract

Studies on the stability of anodic oxides grown on zirconium and its biocompatible alloys Ti-50Zr at.% and Zr-2.5Nb wt.%, in aerated Ringer physiological solution, at 25 and 37 °C, were carried out by comparing their formation charge and their reconstruction charge after dissolution at open circuit in the physiological solution. The stability of oxides grown in the Ringer solution and in a 0.15 mol L-1 Na2SO4 solution was compared. The obtained results show that the stability of these oxides is increased by aging under potentiostatic conditions and can be decreased by the presence of chloride ions in the electrolyte during the anodization process.

Published
2002

35. Rapid microwave-assisted solid-state obtention of Mn3O4 and its electrochemical characterization for application as supercapacitor electrodes.

Author

Silva, João Pedro, Irikura, Kallyni, Biaggio, Sonia R., Bocchi, Nerilso, and Rocha-Filho, Romeu C.

Abstract

A rapid and facile microwave-assisted method coupled with a mild mechanical treatment is proposed to obtain Mn3O4 with good properties to be used as a supercapacitor material. Mn3O4 was produced by thermal decomposition of ε-MnO2 using microwave irradiation in a practical setup and a domestic microwave oven. XRD results, supported by other physical characterizations such as TG/DTA and FTIR and Raman spectroscopy analyses, attested that Mn3O4 was obtained as a single phase after only 5 min of microwave heating. After submitting an oxide sample to a mild mechanical treatment in an adapted ball-mill setup for 30 min, SEM micrographs and BET analyses revealed a particle size in the range of 200–600 nm and a fivefold increase of the specific surface area. The pseudocapacitive behavior of electrodes prepared with the thus obtained Mn3O4 was analyzed by cyclic voltammetry in a 0.1 mol L–1 Na2SO4 aqueous solution. Galvanostatic charge and discharge tests of these electrodes were performed in the 1.0 to 5.0 A g–1 range in the same electrolyte; at 1.0 A g–1, they presented an initial specific capacitance of about 160 F g–1 and good electrochemical stability up to 5000 cycles. [ABSTRACT FROM AUTHOR]

Published
2022
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47. N2–H2 plasma functionalization of carbon fiber fabric for polyaniline grafting.

Author

Ceregatti, Thayara, Kunicki, Lucas, Biaggio, Sonia R., Fontana, Luis C., and Dalmolin, Carla

Subjects
CARBON fibers, POLYANILINES, CARBON electrodes, PLASMA gases, RAMAN microscopy, ELECTROCHEMICAL electrodes
Abstract

Carbon fiber fabric was treated with radiofrequency plasma in a N2/H2 gas mixture to create functional groups with –NHx or –N, thus promoting conditions for polyaniline (PAni) grafting. The morphology and chemical structure of PAni on the carbon fiber surface were assessed by scanning electron microscopy and Raman spectroscopy, showing strong interactions between the PAni and the carbon fiber, especially for the 5‐min plasma‐treated substrate. The electrochemical activity of electrodes consisting of carbon fiber fabric and PAni was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy, which showed fast polarization response and lower charge transfer resistance for electrodes with better interactions between the PAni and the carbon fiber substrate, indicating the occurrence of grafting. [ABSTRACT FROM AUTHOR]

Published
2020
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