Effect of process parameters on the nanoporous structure of anodized alumina

Nanoporous alumina fabricated by the anodizing of Al provides unique, advantageous characteristics such as uniformity, high pore density, controllable pore dimensions, highly ordered structure and simple synthesis procedures. Nanoporous alumina membranes have applications in diverse fields such as tissue engineering, drug delivery, biosensors and templates to synthesize nanowires or nanotubes. The performance of nanoporous surfaces and nanoporous membranes is highly dependent on the pore morphology, size and chemistry as well as their density and homogeneity. One of the fascinating aspects of anodized alumina nanoporous structure is its tunability in pore size, pore density, inter-pore distance and pore depth by simply changing the anodizing parameters, such as current, voltage, time, electrolyte chemistry, electrolyte concentration and temperature. To control the anodizing of Al and obtain desirable properties, an understanding of anodizing conditions on the film characteristics is important. In this study a statistical analysis of the effect of process variables on the nanoporous structure of anodized alumina is examined. Such studies can be extended to anodizing other materials such as niobium and tantalum for various applications including energy storage.