Experimental study on physical properties of nanoporous anodic aluminum oxide by proton implantation

Implantation is a promising method to control the surface characteristics by changing surface energy of target materials. Previously, polymer surfaces have been investigated for the change of their morphology and the corresponding contact angle after implantation. Furthermore, oxide thin films have been studied for how their surface properties are changed by implantation. However, nanoporous oxide materials have rarely explored for the effect of implantation. Here, we investigated the effects of proton implantation on morphological, mechanical, electrical, and surface properties of anodic aluminum oxide (AAO). We prepared nanoporous amorphous AAO films with different thicknesses (5 and 10 μm). Atomic force microscopy (AFM), contact angle (CA) measurements, two-probe electrical measurements, and nanoindentation were used to analyze the physical properties. By increasing fluences from 10¹⁵ to 10¹⁶ ions/cm², CA is significantly changed up to about 40°, but the other properties hardly changed.