Porous anodic alumina layers with modulated pore diameters formed by sequential anodizing in different electrolytes
| Autor: | Leszek Zaraska, Marian Jaskuła, Grzegorz D. Sulka |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Anodizing Nanoporous Mechanical Engineering Oxalic acid Oxide Nanotechnology 02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Isotropic etching 0104 chemical sciences chemistry.chemical_compound Nanopore chemistry Chemical engineering Mechanics of Materials General Materials Science 0210 nano-technology Phosphoric acid |
| Zdroj: | Materials Letters. 171:315-318 |
| ISSN: | 0167-577X |
| DOI: | 10.1016/j.matlet.2016.02.113 |
| Popis: | A high purity (99.999%) Al foil was pre-textured by 1 h of anodic oxidation in 0.3 M oxalic acid at 45 V and room temperature, followed by the chemical etching of as formed irregular oxide layer. As prepared samples were used for fabrication of porous anodic aluminum oxide (AAO) layers with modulated pore diameters by a simple anodization carried out at the same anodizing conditions (potential and temperature) but in a sequentially changed electrolyte (0.3 M H2C2O4 and 0.3 M H3PO4). It was proved that anodization carried out in the oxalic acid result in a relatively fast (~250 nm min−1) formation of porous Al2O3 structure with an average pore diameter of about 30 nm. On the other hand, anodic oxidation in the phosphoric acid electrolyte leads to a much slower (~40 nm min−1) formation of AAO layer with widen nanopores – about 45 nm in diameter. As a result, nanoporous Al2O3 layers with distinguishable nanochannel segments having different pore diameters were obtained. Moreover, no loss of hexagonal pore order was observed even when the anodization was carried out in phosphoric acid at the potential of 45 V which is far away from the self-ordering regime for this electrolyte (~195 V). |
| Databáze: | OpenAIRE |
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