Synthesis of Nanoporous Anodic Alumina by Anodic Oxidation of Low Purity Aluminum Substrates

Abstract

The aim of this chapter is to present some recent findings on the fabrication of anodic aluminum oxide (AAO) layers by anodization of low purity aluminum substrates. The use of low purity, technical aluminum alloys, instead of high purity substrates, can significantly reduce the cost of AAO fabrication, however, this can also affect the structure and properties of as produced alumina layers. Here, we focused on the comparison of oxide layer growth on substrates with different Al contents, as well as on the new procedures used for the synthesis of well-ordered nanoporous oxides from technical aluminum alloys. Some applications of the formed nanoporous AAO layers are presented. IntroductionDuring the recent years nanomaterials have received significant attention due to many unique chemical and physical properties that make them promising materials for various modern applications. As a result, nanotechnology is now one of the most popular sciences which have opened a lot of new perspectives in almost all scientific disciplines [1]. Up to now, the main problem that limits the practical application of nanomaterials is a relatively high cost of nanofabrication [2]. That is why considerable research efforts focus on the design and control of novel nanostructures via innovative synthetic strategies. A big attention has been paid to development a simple and inexpensive method of nanofabrication that can be used not only in a laboratory scale but also could have some potential for a commercial-scale implementation. Among numerous strategies reported in the literature, one of the most popular method for fabricating nanostructured oxide layers on the metal surface is controlled anodic oxidation (anodization) of metals under

Controlling the Multiscale Topography of Anodized Aluminum Oxide Nanowire Structures for Surface-Enhanced Raman Scattering and Perfect Absorbers

“…AAO with controllable pore diameters ranging from 20 to 300 nm, interpore distance of 25–500 nm, and pore depth of 1–200 μm have been fabricated using a two-step anodization technique . The extraordinary hardness, corrosion and abrasion resistance, − chemical, electrical, mechanical, and thermal stability, , and fabrication flexibility to control structural parameters of AAO provide scope to various applications. − …”

Characterization of nanopores arrangement of anodic alumina layers synthesized on low-(AA1050) and high-purity aluminum by two-step anodizing in sulfuric acid with addition of ethylene glycol at low temperature

“…What is more, additions of various modifiers to well know electrolytes [21] or to the new ones are recently reported in numerous papers [20,[22][23][24]. Usually the anodized aluminium is high purity (99.99%), but there are many papers about anodized aluminum alloys [21,[25][26][27][28][29], because they are generally less expensive and more accessible then highpurity aluminum.…”

Innovative Applications of Cerium Oxide-Based Materials in Civil Engineering, Automation, and Energy Sectors

“…The topology of the anodic aluminum oxide (AAO) layers depends on various factors during layer formation, including: (i) nature and concentration of the contact electrolyte [143]; (ii) applied current density or formation voltage [128,144]; (iii) composition of the to-be-anodized aluminum alloy [145][146][147][148][149] and its structure [150]; (iv) temperature [151]; (v) duration [55,152]; (vi) presence of additives [153], including Ce(IV) species [154], and of course, (vii) preliminary surface treatment [155][156][157]. Additionally, it should be mentioned that anodization at rather high voltages alters the process mechanism, converting it to plasma electrolytic oxidation (PEO).…”