Preparation of titania microfiltration membranes supported on porous Ti-Al alloys

A TiO₂ membrane supported on a planar porous Ti-Al alloy was prepared by combination of electrophoretic deposition and dip-coating. In the electrophoretic deposition process, the membrane thickness increased linearly with the square root of the deposition time, while increased with decrease of the suspension viscosity. The perfect TiO₂/Ti-Al composite membrane was obtained by further dip-coating modification. SEM images showed that the surface of the membrane was defect-free. XRD result indicated that rutile TiO₂ still remained in the membrane bulk as the main phase, while a new phase titanium oxides with the form of Ti_xO_y, where y is less than 2x, was also observed. The supported TiO₂/Ti-Al composite membrane had an average pore size of 0.28 μm, a thickness of 40 μm or so and a pure water flux of 3037 L m^-2 h^-1 bar^-1.