Self cleaning aluminum alloy substrates

Abstract

Self-cleaning aluminum alloy substrates and methods of making the same are disclosed. In one embodiment, a substrate is provided, the substrate including an aluminum alloy body, an anodic oxide zone having micropores within a surface of the aluminum alloy body, the anodic oxide zone being substantially impermeable to contaminants, and a photocatalytic film located on at least a portion of the anodic oxide zone, wherein the photocatalytic film comprises photocatalytically active semiconductor. In one embodiment, a method is provided, the method including the steps of forming an anodic oxide zone in at least a portion of an aluminum alloy base, forming a photocatalytic film, the photocatalytic film being located on the anodic oxide zone, and sealing the anodic oxide zone with a sealant, wherein, as sealed, the anodic oxide zone is substantially impermeable to contaminants.

1 . A method comprising:
 forming an anodic oxide zone in at least a portion of an aluminum alloy base;   forming a photocatalytic film, wherein the photocatalytic film is located on the anodic oxide zone; and   sealing the anodic oxide zone with a sealant, wherein, as sealed, the anodic oxide zone is substantially impermeable to contaminants.   
     
     
         2 . The method of  claim 1 , wherein the sealant is a solution comprising water, nickel ammonium sulphate, nickel acetate, nickel sulphate, cobalt acetate, cobalt sulphate, nickel/cobalt acetate, sulphate silicate, sodium silicate or combinations thereof. 
     
     
         3 . A method comprising:
 cleaning an aluminum alloy base with a cleaner, thereby forming an aluminum oxide layer on the aluminum alloy base; and   applying a solution having a photocatalytically active semiconductor to the aluminum oxide film, thereby forming a photocatalytically active semiconductor film, wherein the photocatalytically active semiconductor film is adherent to the aluminum alloy base.   
     
     
         4 . The method of  claim 3 , wherein the cleaner is selected from the group consisting of an alkaline cleaner, an acidic cleaner and combinations thereof. 
     
     
         5 . The method of  claim 3 , wherein the aluminum oxide film has a thickness of not greater than about 800 nanometers. 
     
     
         6 . The method of  claim 3 , further comprising:
 chemically brightening and then desmutting the aluminum alloy base before the applying the solution step.   
     
     
         7 . A method comprising:
 forming an anodic oxide zone within at least a portion of an aluminum alloy base;   forming a polymer film, wherein the polymer film is located on at least a portion of the anodic oxide zone;   sealing, concomitant to the forming a polymer film step, the anodic oxide zone, thereby making the anodic oxide zone substantially impermeable to contaminants; and   forming a photocatalytic film, wherein the photocatalytic film is located on at least a portion of the polymer film.   
     
     
         8 . The method of  claim 7 , further comprising:
 forming a coupling agent film, wherein the coupling agent film is located between at least a portion of the polymer film and the photocatalytic film.   
     
     
         9 . The method of  claim 8 , wherein the coupling agent film includes photocatalytically active semiconductor.