Synthesis and characterisation of microporous titania membranes by dip-coating of anodised alumina substrates using sol–gel method

The aim of this work was to synthesis microporous titania membranes by dip-coating of symmetric mesoporous anodised alumina substrates using sol–gel method. A stable titania sol containing nanoparticles was first prepared by establishing the proper values of the acid/alkoxide and the water/alkoxide molar ratios and pH. The titania sol was then utilised to dip-coat the anodised alumina substrates. The effects of dipping time, withdrawal rate, and sintering temperature were studied for both single- and double-layer coated samples. The thickness, structure and phase analysis of the coated membranes were characterised using thermogravimetric analysis, scanning electron microscopy and X-ray diffraction. The process conditions to achieve uniform, microporous titania coatings on the mesoporous alumina substrates were proposed.