Effect of Different Polishing Methods on Anodic Titanium Dioxide Formation

Abstract

Among various methods of synthesis of nanostructured TiO2, a self-organized anodization is the most commonly used and discussed in the literature. However, different methods of pretreatment of Ti before anodic titanium dioxide (ATO) formation are not often addressed. Therefore, various polishing procedures based on mechanical, chemical, electrochemical, and combined electrochemical with chemical pretreatments were examined to establish whether they represent effective methods for smooth Ti surface preparation before anodization. The ATO layers were prepared via two-step anodization carried out in an ethylene glycol solution containing fluoride ions at 20°C and under the anodizing potential of 60 V. The influence of applied polishing method on the cell size, pore diameter, pore circularity, pore density, and porosity of the top ATO layer was studied. In addition, the effect of polishing procedure on cell arrangement in ATO films was also investigated. The quantitative analyses of the regularity of cell arrangement, based on the regularity ratio derived from bottom-view SEM images, showed that the type of polishing procedure does not affect the cell order.