Nanoporous titania-coated alumina membranes: sol-gel synthesis and characterisation

In this work, nanoporous titania top layers were deposited by dip-coating process on microporous alpha-alumina substrates using the sol-gel process. The alumina substrates were synthesized by slip casting method using Taguchi optimising approach. The microporous substrate was then used to coat nanoporous titania layers by the sol-gel method. The thickness, pore size, structure and permeability of the membranes were characterised using SEM, XRD, STA and Hg-Porosimetry. The process conditions to achieve defect-free nanoporous titania layers with the average pore size of about 4 nm coated on the microporous alumina substrates with the average pore size of about 270 nm were determined.