Cellular Porous Anodic Alumina Grown in Neutral Organic Electrolyte I. Structure, Composition, and Properties of the Films

Abstract

Anodic alumina films with cellular porous structure grow in neutral organic electrolytes with low water content and containing ethylene glycol and a large dicarboxylic acid. An Al carboxylate precipitates in the pore and is extruded from the coating. The porous structure develops even though the current efficiency for film formation is near 95%. The coating matrix contains substantial organic material, 15 wt % by thermal analysis. It is an oxide/organic composite with higher field strength and lower dielectric constant than pure anodic alumina. © 2000 The Electrochemical Society. All rights reserved.