Síntese e formação de nanoestruturas e filmes de alumina anódica porosa
Franci, Patrícia Monteiro
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This paper presents a methodology for obtaining the porous anodic alumina. anodization of aluminum in acidic electrolytes may specifically result in different types of oxide films as a barrier type porous type. Anodic alumina is formed with a regular porous structure on the nanometer scale when using the technique of two-step anodizing in galvanostatic mode, where the applied current density is fixed and observing the variation of potential along the way. In this study, we used a factorial design to investigate the effects of variables on morphology and electrochemical responses, the planning matrix allowed mapping the proposed system, and the influence of the variables chosen in three different responses from electrochemical anodization curves. For this study three experimental parameters were chosen, as follows: temperature, electrolyte concentration and current density, all varying in two levels. The electrochemical response parameters chosen were: slope of the curve, the maximum potential and steady potential. These electrochemical responses provide information about the mechanism and kinetics of growth of oxide films, being important in the verification of some properties of the final preparation. As a result , and based on Pareto charts , it can be seen that the current density is the parameter most affected by the slope of the curve is related to the rate of growth of the oxide barrier formed initially. On the other hand , the maximum potential, early processes related to the source and opening pore was observed that the three variables influencing this response. Finally, the stationary potential important parameter related to the dissolution rate and the formation of porous oxide in dynamic equilibrium noted that all three variables were significant in the process. This study enabled to view the influence of independent variables and their cross- tillage on the growth of anodic alumina film .Os PLA films were characterized morphologically interactions to verify the homogeneity of the structures and relationships of the variables in the pore radius of AAP .