Membrane supporting structures

A method of fabricating a porous support for membranes that are suitable for capturing gases or liquids, the method comprising the following steps in order:

• providing a porous support comprising a first material that has an outer surface and an inner surface;
• polishing the outer surface to generate a polished outer surface;
• coating a layer of ceramic nanospheres on the polished outer surface;
• coating a layer of sol-gel solution onto the ceramic nanosphere layer that is coated on the outer surface of the porous support, the sol-gel solution comprising a surfactant;
• removing at least the surfactant from the sol-gel layer on the porous support to generate nanopores, thereby forming a nanoporous layer on top of the porous support;
• wherein a size of the nanopores is based, at least in part, on a molecular dimension of the surfactant.