Fabrication of Commercial Nanoporous Alumina by Low Voltage Anodizing

THE PRESENT work is considered as an introductory study on the procurement of membranes from nanoporous alumina through one-step anodization. The nonporous alumina was obtained by anodizing the specimens at low voltage 5V for 20 minutes in phosphoric acid. The self-ordered porous arrangements can be acquired by using this process. The variables of space between pores, high pore density on the alumina surface are subjected to comparison with membranes which obtained by other methods. The mixture of phosphoric acid and chromium trioxide is used for removing the formed aluminum oxide after the first anodization. The self-ordered porous configuration is obtained at the second anodization step at the same conditions of the first anodization process. The nonporous alumina membrane was subjected to characterization of its surface morphology by scanning electron microscopy SEM and the electric properties were examined by using the electrochemical impedance test EIS. The formed nanoporous structures can be used for fabrication of sensor elements.