• Vol 8, No 8 (2017)
  • Metalurgy and Material Engineering

An Analysis of the Electrolyte Resistivity Effect on the Pore Diameter and Pore Density of Anodic Aluminium Oxide (AAO) Films Produced by Single-Step Anodization

Vika Rizkia, Johny Wahyuadi Soedarsono, Badrul Munir, Bambang Suharno

Publish at : 27 Dec 2017 - 00:00
IJtech : IJtech Vol 8, No 8 (2017)
DOI : https://doi.org/10.14716/ijtech.v8i8.742

Cite this article as:
Rizkia, V., Soedarsono, J.W., Munir, B., Suharno, B., 2017. An Analysis of the Electrolyte Resistivity Effect on the Pore Diameter and Pore Density of Anodic Aluminium Oxide (AAO) Films Produced by Single-Step Anodization. International Journal of Technology. Volume 8(8), pp.1479-1488
Vika Rizkia - Politeknik Negeri Jakarta
Johny Wahyuadi Soedarsono Universitas Indonesia
Badrul Munir Universitas Indonesia
Bambang Suharno Universitas Indonesia
Email to Corresponding Author


Nanoporous anodic aluminum oxide (AAO) layers were successfully fabricated on aluminum foil through an anodizing process in oxalic acid and mixed electrolytes of sulfuric and oxalic acid. The effect of electrolyte resistivity on the morphology of nanoporous AAO, such as pore diameter and pore density, was investigated. The nanoporous AAO layers‘bmorphology was examined using field emission scanning electron microscopy (FE-SEM) and analyzed using image analysis software. The results showed that anodizing in mixed electrolytes (sulfuric and oxalic acid) produced a much smaller pore diameter and a much higher pore density at lower voltage compared to anodizing in a single oxalic acid. For the anodizing process in oxalic acid, the pore diameters ranged from 14 to 52 nm, and the pore density ranged from 34?106 pores in 500×500 nm2. The anodizing process in the mixed electrolytes resulted in pore diameters within the range of 7?14 nm, and the pore densities were within the range of 211?779 pores in 500×500 nm2. Overall, increasing the electrolyte resistivity within the same solution leads to decreased pore diameter.

Anodic Aluminum Oxide; Electrolyte resistivity; Mixed electrolytes; Oxalic acid; Pores


Nanoporous AAO was successfully fabricated on aluminum foil through an anodizing process in oxalic acid and a mixed electrolyte of sulfuric and oxalic acids. Generally, the type of electrolyte and its resistivity can control pore diameter and density. For the anodizing process in oxalic acid, the measured pore diameter was in the range of 14.3±2.3 to 52.9±5.5 nm, and the pore density was in the range of 34±1.2 to 106±2.4 pores in 500×500 nm2. The higher the oxalic acid concentration, the wider the pore diameter and the lower the pore density produced. Adding 3 M sulfuric acid to oxalic acid electrolyte produced much smaller pore diameters and much higher pore densities at lower voltage compared to anodizing in a single oxalic acid. This mixed electrolyte produced a pore morphology as small as 7.2±1.2 nm in diameter and a density of 779.3±17.5 pores per 500×500 nm2. The significant difference in the diameter was attributed to the electrolyte’s acidity, which affects the electrolyte’s resistivity. Increasing the electrolyte resistivity within the same type of solution led to decreasing the pore diameter.


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