Manufacturing of new nano-structured ceramic–metallic composite microporous membranes consisting of ZrO2, Al2O3, TiO2 and stainless steel

Frequently, the membrane employed in a traditional nano-filtration (NF) or gas separation (GS) membrane device consists of a polymeric material, having significant disadvantages including a restricted mechanical, chemical and thermal stability. As an alternative for the polymeric membranes, ceramic membranes with an improved stability have been introduced, but the current membranes still suffer from stability problems (e.g. brittle material, restricted chemical stability in water vapour). This paper reports the preparation of novel hybrid metallic-ceramic membranes, based on a porous 316L stainless-steel support material. The optimized membranes were made by deposition of a fine suspension with a particle size of ~ 180 nm, a colloidal sol with a particle size of ~ 30 nm and a nano-particle sol with a particle size of ~ 5 nm and show a comparable multilayer structure as current ceramic membranes for micro-, ultra- and nano-filtration and gas separation. The essential new features of the membranes include the use of an alternative metallic support material, which provides a high mechanical stability to the membrane, and the application of zirconia- and titania based functional membrane layers, which display a high chemical and thermal stability for potential filtration or gas separation applications.