A model for ceramic membrane formation by dip-coating

The wet ceramic membrane formation on a porous substrate in the dip-coating process plays a key role for high quality separation layers of the asymmetric membranes. A model to quantitatively describe the membrane growth under a driving force of the capillary filtration is derived on the basis of the slip-casting model. As an example, alpha-Al2O3 microfiltration membranes were prepared by dip-coating. The influence of the dipping time on the membrane thickness was examined. The data for alpha-Al2O3 microfiltration membranes fit the predictions made by the model well. In addition, the results of gamma-Al2O3 membranes demonstrate that this model is also valid for ultra-filtration membrane formation by dipping sols. (C) 1999 Elsevier Science Limited. All rights reserved.