Modificación electroquímica de aluminio en ácido oxálico como una herramienta para el diseño de microreactores basados en Al-Al₂O₃

Electrochemical oxidation was studied using oxalic acid (1.6 M), varying some conditions, as: current density (I_a = 1-3 A/dm²), electrolytic bath temperature (T_a = 40-50 °C), anodizing time (ta = 40-100 min) and a post-anodizing treatment (PA) at different current densities (I_a = 1-3 A/dm²) with a constant post-anodizing time (t_PA = 40 min) and increasing the treatment time (tPA = 0-120 min) at constant current density (Ia = 2 A/dm2). The variation of these conditions showed that the Al₂O₃ formation depends on two fundamental processes. First, it is the generation of an anodic oxide layer followed by its dissolution on internal and external surface of the pore. The influence of each variable on these two stages causes the generation of layers with texture and roughness specific characteristics. Similarly, it was demonstrated that independently of the geometric shape, a morphological equivalence of the anodic Al₂O₃ in the aluminum substrates was obtained. Furthermore, a trend in the pressure drops: MACL¹¹⁰⁰ > MAE⁴⁰ > MAE²⁰ > MAE¹⁰ > MACL³⁵⁰ was observed; this performance depends of the spatial distribution and cells number.