Patent ID: 6613384
Filing Date: 2003-09-02
Classification: B01D,C01B

Abstract:
A method for manufacturing a dense and crack-free ceramic membrane having a dense film or coating on a porous substrate which selectively transports oxygen when it is subjected to an oxygen partial pressure gradient, which comprisesa) adding a pore former to a powder to form a mixture, heating said mixture to remove the pore former and to partially sinter the mixture to form said porous substrate, b) preparing a colloidal dispersion or slip from a powder having the same chemical composition and same particle size distribution as the powder used in a), c) dipping said substrate into said dispersion or slip where the liquid phase in said dispersion or slip is drawn into the pores of the substrate through capillary action and a layer of particles is deposited on the surface of the substrate and a further deposition of particles occurs when the substrate is withdrawn from the dispersion or slip by a dip-coating action, and d) sintering the substrate with the layer from c) at a temperature which results in formation of a dense film or coating supported on said substrate that retains open porosity.