PREPARATION OF ALUMINA MEMBRANES BY TAPE CASTING AND DIP COATING

The preparation of an alumina ultrafiltration membrane with a mean por e size of 6 . 5 nm was performed by slip casting or tape casting of th e support, dip coating ol tape casting of the intermediate layer, foll owed by dip coating of the top layer. Controlled porosity and pore siz e in the support were obtained by the addition of starch particles whi ch were subsequently quently burned out. A conventional process bused on dip coating to create the intermediate layer was used initially. An alternative process was developed, based on tape casting of the suppo rt and the intermediate layer, followed by lamination and sintering in one step. Very good linkage between the support and the intermediate layer was obtained by the alternative process, as well as an excellent control of rite intermediate layer thickness and surface finish. Pore size, pore size distribution and porosity, were determined for each p art of the membrane. The gas and liquid permeabilities were also measu red. (C) 1996 Elsevier Science Limited