A facile nanoparticle doping sol-gel method for the fabrication of defect-free nanoporous ceramic membranes

Enhanced α-alumina tight ultrafiltration (UF) membranes were fabricated by using a facile nanoparticle doping sol-gel method. The addition of nanoparticles could not only promote the phase transition of alumina from γ to α phase at low temperature, but also play an important role in the defect-patching of substrate during the layer-forming process. The membrane surface was defect-free and smooth. Additionally, a relatively small pore size was observed. The nanoparticle doping sol-gel method showed a good potential for fabricating such integrated UF membranes, which are high performance interlayers for ceramic nanofiltration (NF) membranes.