Investigation of Composite Membranes by Developing Mesoporous Alumina Layer on Stainless Steel Substrate

Inorganic ceramic membranes are more preferable for waste water treatment applications than polymeric ones due to their higher thermal, mechanical and chemical stability. Transport resistance of these membranes can be diminished by producing thinner layers of them on a thicker porous substrate with larger average pore size. In this paper, the preparation of a novel metallic-ceramic composite membrane was studied, which incorporates desirable properties of both ceramic membrane and porous metallic substrate. For this purpose, a mesoporous alumina membrane layer was developed on a porous stainless steel support by immersion coating method. Sufficient adhesion of membrane layer to the substrate is considered to be an important characteristic, which is controlled by factors such as membrane layer thickness and purification of precursor sol. The influence of the latter was studied by preparing top layers using sols purified with filters of different pore size. The prepared membranes were characterized using scanning electron microscope (SEM), X-ray diffractometer (XRD) and N2- adsorption/desorption measurements (BET analyses). The results revealed that γ-alumina membrane with 3-4 micron thickness and 4.5-4.6 (nm) pore size can be produced and its adhesion to the substrate can be improved by further purification of the sol.

کلیدواژه ها:

Metallic-ceramic composite membrane ، interfacial adhesion ، mesoporous aluminamembrane ، purification