マロン酸を用いたアノード酸化ポーラスアルミナの自己規則化機構の検討

Abstract

The effect of electrolysis conditions on the self-ordering of the cell arrangement of anodic porous alumina grown in malonic acid solution was investigated for the clarification of the mechanism. Because the cell arrangement of porous alumina is affected by the roughness of the substrate surface, the aluminum substrates were pre-treated by electropolishing followed by chemical polishing to modify the substrate surface and make it suitable for uniform porous film growth. By lowering the electrolyte temperature, the high voltage anodizing accompanying high current density without appearance of local current concentration, i.e., burning, could be archived to obtain self-organized porous alumina. Further, current density could be increased more by increasing malonic acid concentration. The porosity of anodic alumina formed in malonic acid solution was 0.07, regardless of the anodizing voltage. From the above results, it was confirmed that high current density, i.e., high electric field strength is the key controlling factor in the self-ordering of anodic porous alumina.