A Model for the Formation of Niobium Structures by anodization
| Autor: | Lilian Vanessa Rossa Beltrami, Sandra Raquel Kunst, Luciane Thaís Fuhr, Ana Carolina Viero Bianchin, Ester Schmidt Rieder, Célia de Fraga Malfatti, Guilherme Reis Maldaner, Cláudia Trindade Oliveira |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Anodização
Materials science Niobium Oxalic acid Oxide Energy-dispersive X-ray spectroscopy chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences Oxalate chemistry.chemical_compound General Materials Science Materials of engineering and construction. Mechanics of materials Dissolution Porous oxide Anodizing Mechanical Engineering 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Nióbio chemistry Chemical engineering Mechanics of Materials TA401-492 Ammonium niobium oxalate Anodization 0210 nano-technology Fluoride |
| Zdroj: | Repositório Institucional da UFRGS Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS Materials Research v.20 n.4 2017 Materials research (São Carlos. Online) Universidade Federal de São Carlos (UFSCAR) instacron:ABM ABC ABPOL Materials Research, Volume: 20, Issue: 4, Pages: 1010-1023, Published: 25 MAY 2017 Materials Research, Vol 20, Iss 4, Pp 1010-1023 (2017) |
| Popis: | The fluoride use for anodizing electrolytes has been primarily responsible for the formation of nanoporous oxides at valve metals, except aluminum, since it causes a dissolution process. This study presents the formation of an oxide model according to the following anodizing parameters: 100 V, 12.73 mA/cm2, room temperature and the niobium samples anodized in niobium oxalate and oxalic acid electrolytes without and with the addition of HF for 5, 30 and 60 min. The anodized samples were analyzed morphologically by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM) and the hydrophobicity of the samples was assessed by the sessile drop method. The presence of fluor in the niobium oxalate electrolyte formed oxides with lower a dissolution and a low hydrophobicity compared to the one formed in oxalic acid was attributed to the incorporation of niobium and oxalate ions. Thereby, the model proposed in this paper showed that during anodization the migration of the fluoride ion into the oxide occurs at high speed, which results in the formation of microcones, leading to the formation of discrete layers of porous oxide. |
| Databáze: | OpenAIRE |
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