Corrosion Resistance of ZrO_2 Nanofiltration Membranes

A stable ZrO2 polymeric sol was synthesized through a sol–gel method using zirconium n-propoxide as precursor. Disk α-Al2O3 supported mesoporous ?-Al2O3 membrane with an average pore size of 5–6 nm was used as support for nanofiltration membranes deposition. Defect-free ZrO2 nanofiltration membranes superimposed on these supports were fabricated via dip-coating method followed by drying and calcination. The chemical stabilities of supported ZrO2 nanofiltration membranes were detemined by static corrosion tests. Results showed that unsupported ZrO2 membranes calcined at 350 ℃ and 400 ℃ were found to be chemically stable in a pH window of 1–13. Supported ZrO2 nanofiltration membrane calcined at 400 ℃ was found to be chemically stable in a window of pH = 2–12. While the membrane calcined at 350 ℃ showed reduced PEG-rentention properties after immersed in pH = 12 and 2 solutions. The result can be attributed to the amorphous phase presented in zirconia separation layer as well as the chemical instability of the γ-Al2O3 layer beneath.