COMPUTER-SIMULATION OF INORGANIC MEMBRANE MORPHOLOGY .3. ANODIC ALUMINA FILMS AND MEMBRANES

The morphology of anodic alumina films and membranes has been simulate d. The model takes into account: (1) the number of potential centres o f anodic oxidation; (2) the mean distance between these centers; (3) t he creation of a triangular network in order to anodize all the alumin ium surface; and (4) the heterogeneous composition of cells. The gener al distribution of the cells has been recreated and characterized usin g a radial function of distribution. The area of cells is made up of t hree parts: the pore, anion-contaminated alumina, and relatively pure alumina. The relative proportions of each part have been calculated as a function of the cell size and experimentally determined relations. Different stages of the dissolution of anodic alumina, which lead to c hanging pore sizes and shapes, have also been simulated using the expe rimentally determined rates of solubility for anion-contaminated and r elatively pure alumina. Very good agreement has been observed between morphology and pore structure of simulated and real anodic alumina fil ms and membranes. (C) 1995 Academic Press, Inc.