Nanoscale Topography: A Tool to Enhance Pore Order and Pore Size Distribution in Anodic Aluminum Oxide

Abstract

In nanoporous alumina, surface pretreatment prior to the anodization process plays a crucial role in the nanopore formation, strongly influencing their organization and size uniformity. In this work, an effective control of the anodic aluminum oxide (AAO) hexagonal order and nanopore size uniformity was achieved by simply changing the initial aluminum electropolishing pretreatment time. A drastic change in the nanoscale topography of the treated aluminum foils was observed, and intrinsic features were revealed. The effect of such distinct landscapes on the AAO surface after first and second anodization processes was studied in detail. Quantitative analysis of the AAO surface after the second anodization enabled establishing a close correlation between aluminum surface roughness and AAO pore order and regularity.