Structural engineering of nanoporous alumina by direct cooling the barrier layer during the aluminum hard anodization

Controllable and a new effective anodization method for continuous 3D structural engineering of porous anodic alumina nanostructure is introduced. This method is based on the controlling of ion production and its mobility at the barrier layer. The ion productions in the metal–oxide interface and ion mobility inside the oxide are controlled by direct cooling of barrier layer via sprinkling the cold solution on the back side of the aluminum template during the hard anodization. Pulse sprinkling able to create current peak and this peak changes the pore diameter of porous anodic alumina. This new technique is done for variety of anodization voltage and various electrolyte concentrations and it was investigated how these parameters in the vicinity of pumping can control the pore and barrier layer geometry. This method effectively decreases the recovery and response time of the anodization current in oxalic and oxalic/phosphoric acid mixture.