Experiment and research on development and characterizations of anodic alumina membrane for use in hemodialysis

Objective: The correlation between various formative conditions and the pore characterizations of the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic alumina membrane. Methods: High purity aluminum foils are used as the starting materials. The anodization is conducted in three types of electrolytes, 3% sulfuric acid, 5% sulfuric acid and 2.7% oxalic acid, respectively, with different voltages at 0℃ for 48h. The characterizations of the pore size, the effective porosity and the pore porosity are observed and determined by scanning electron microscopy. The hydraulic conductances of the membranes are measured to confirm that the pores are open and evaluate the permselectivity of the membranes. Results: The experimental result shows that the ordered pore arrays are obtained for oxidation under our experimental conditions. With the increasing of the voltage, the pore size and pore porosity increased significantly ( P < 0.05) , while the effective porosity decreased significantly ( P < 0.05 ) with the same electrolyte. The pore size formed in 3% sulfuric acid or 5% sulfuric acid is much smaller than in 2.7% oxalic acid as an electrolyte. The hydraulic conductance of anodic alumina membrane that formed under our experimental condition is higher than those of the membranes are available currently used in clinical. Conclusion: The results suggest that the optimal conditions for the formation of anodic alumina membrane that used in hemodialysis are in 3% or 5% sulfuric acid with 12.5V to 17.5V at 0℃ for 48h.