Highly permeable supported γ-alumina membranes for water purification

Nanofiltration with inorganic meso-porous membranes is being considered more and more for water purification applications. For specific applications inorganic membranes may have advantages over organic polymer-based membranes due to their rigid pore structure, and thermochemical stability. However, the permeability and, partly through that, the permselectivity of inorganic membranes need to be improved before they can really become competitive. To achieve that, the membrane structure and its synthesis must be optimized and developed further to meet challenging membrane design requirements. This work shows how these requirements can be met in the synthesis of thin homogeneous supported meso-porous γ-alumina membranes on top of a hybrid α-Al₂O₃ support. Initial water permeation and permselectivity testing of these membranes gave promising results and perspectives of further improvement.