Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic Acid
In this work, aluminum (Al) anodization in malic acid electrolytes of different concentrations (0.15 M, 0.25 M, and 0.5 M) was studied. The close-packed hexagonal pore structure was obtained for the first time in this organic acid in a 0.5 M solution, at 250 V and temperature of 5 °C. Moreover, the...
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doaj-99cfdefcac694f54b892f7b630b7a9052020-11-25T02:42:43ZengMDPI AGMaterials1996-19442020-09-01133899389910.3390/ma13173899Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic AcidLidia Zajączkowska0Dariusz Siemiaszko1Małgorzata Norek2Institute of Materials Science and Engineering, Faculty of Advanced Technologies and Chemistry, Military University of Technology, Str. gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, PolandInstitute of Materials Science and Engineering, Faculty of Advanced Technologies and Chemistry, Military University of Technology, Str. gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, PolandInstitute of Materials Science and Engineering, Faculty of Advanced Technologies and Chemistry, Military University of Technology, Str. gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, PolandIn this work, aluminum (Al) anodization in malic acid electrolytes of different concentrations (0.15 M, 0.25 M, and 0.5 M) was studied. The close-packed hexagonal pore structure was obtained for the first time in this organic acid in a 0.5 M solution, at 250 V and temperature of 5 °C. Moreover, the process was investigated as a function of the number of cycles carried out in the same electrolyte. A repetition of anodization under seemingly the same external electrochemical parameters (applied voltage, temperature, etc.) induced serious changes in the electrolyte. The changes were reflected in the current density vs. time curves and were most evident in the higher concentrated electrolytes. This phenomenon was tentatively explained by a massive incorporation of malate anions into anodic alumina (AAO) framework. The impoverishment of the electrolyte of the malate anions changed internal electrochemical conditions making easier the attraction of the anions to the Al anode and thus the AAO formation. The electrolyte modification was advantageous in terms of pore organization: In a 0.25 M solution, already after the second anodization, the pore arrangement transformed from irregular towards regular, hexagonal close-packed structure. To the best of our knowledge, this is the first observation of this kind.https://www.mdpi.com/1996-1944/13/17/3899aluminumanodizationmalic acidelectrolyte agingself-ordering regime |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Lidia Zajączkowska Dariusz Siemiaszko Małgorzata Norek |
spellingShingle |
Lidia Zajączkowska Dariusz Siemiaszko Małgorzata Norek Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic Acid Materials aluminum anodization malic acid electrolyte aging self-ordering regime |
author_facet |
Lidia Zajączkowska Dariusz Siemiaszko Małgorzata Norek |
author_sort |
Lidia Zajączkowska |
title |
Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic Acid |
title_short |
Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic Acid |
title_full |
Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic Acid |
title_fullStr |
Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic Acid |
title_full_unstemmed |
Towards Self-Organized Anodization of Aluminum in Malic Acid Solutions—New Aspects of Anodization in the Organic Acid |
title_sort |
towards self-organized anodization of aluminum in malic acid solutions—new aspects of anodization in the organic acid |
publisher |
MDPI AG |
series |
Materials |
issn |
1996-1944 |
publishDate |
2020-09-01 |
description |
In this work, aluminum (Al) anodization in malic acid electrolytes of different concentrations (0.15 M, 0.25 M, and 0.5 M) was studied. The close-packed hexagonal pore structure was obtained for the first time in this organic acid in a 0.5 M solution, at 250 V and temperature of 5 °C. Moreover, the process was investigated as a function of the number of cycles carried out in the same electrolyte. A repetition of anodization under seemingly the same external electrochemical parameters (applied voltage, temperature, etc.) induced serious changes in the electrolyte. The changes were reflected in the current density vs. time curves and were most evident in the higher concentrated electrolytes. This phenomenon was tentatively explained by a massive incorporation of malate anions into anodic alumina (AAO) framework. The impoverishment of the electrolyte of the malate anions changed internal electrochemical conditions making easier the attraction of the anions to the Al anode and thus the AAO formation. The electrolyte modification was advantageous in terms of pore organization: In a 0.25 M solution, already after the second anodization, the pore arrangement transformed from irregular towards regular, hexagonal close-packed structure. To the best of our knowledge, this is the first observation of this kind. |
topic |
aluminum anodization malic acid electrolyte aging self-ordering regime |
url |
https://www.mdpi.com/1996-1944/13/17/3899 |
work_keys_str_mv |
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