Aluminium wire anodisation: Controlling the thickness, porosity, and morphology of alumina layer for the application of solid-phase microextraction

ABSTRACT

In this study, the aluminium wire anodisation process to generate a cracked alumina layer with a high surface area for the application of solid-phase microextraction was studied. The effect of aluminium anodisation variables, including anodisation voltage, anodisation time, electrolyte temperature, and electrolyte concentration was investigated and the cracked alumina layer formation mechanism was revealed. Characterisation of the generated alumina layer was carried out by scanning electron microscope (SEM) and adsorption and desorption isotherm of nitrogen by Brunauer–Emmett–Teller (BET). Under optimised conditions, an adherent cracked alumina layer with high porosity and thickness was achieved. The highest surface area was obtained in anodisation voltage of 15 V, anodisation time 120 min, electrolyte temperature 25 °C, and electrolyte concentration 3.0 mol L⁻¹. The fabricated fibres were used to headspace solid-phase microextraction of n-butanol from aqueous samples and then injected into a gas chromatography-flame ionisation detector (GC-FID) to evaluate their efficiency. Results showed that the fibres which were prepared in the optimum conditions have an extraction efficiency distinguishably higher than other types.

KEYWORDS:

• Adsorption capacity
• aluminium
• cracked alumina
• gas chromatography
• porous structure

Acknowledgments

We gratefully acknowledge the partial support for this work from The Research Council of the Iran University of Science and Technology.

Disclosure statement

No potential conflict of interest was reported by the author(s).