Basic views on the preparation of porous ceramic membrane layers - A comparison between amorphous and crystalline layers, leading to a new method for the preparation of microporous continuous layers

The preparation of silica-based supported microporous membranes depends on nucleation and solidification/crystal growth rates, i.e. both should be as high as possible. Most important for the membrane phase is its continuity, which is easily achieved for amorphous materials and extremely difficult to accomplish for crystalline materials. This paper outlines how, in a combination of steps, an amorphous phase can be converted into a crystalline phase, providing membrane continuity as well as unique pore size distribution and high stability.