Preparation and corrosion-resistant property of mesoporous ZrO₂ membrane

Preparation and characterization of mesoporous ZrO₂ membrane with the pore sizes less than 10 nm were studied. A stable ZrO₂ sol with a mean particle size about 100 nm was successfully synthesized with zirconium n-propoxide as precursor through a colloidal sol-gel route. PVA was selected as the drying chemical controlling additive to modulate the viscosity of sol suitable for membrane formation. Y(NO₃)₃·6H₂O was used as a Y-precursor to form Y-stabilized ZrO₂. Defect-free mesoporous ZrO₂ membrane superimposed on a-Al₂O₃ support disk with a mean pore size of 70 nm was fabricated via dip-coating and subsequently calcined in the temperature range of 450-650°C. The effect of calcination temperature on the properties of unsupported ZrO₂ membrane (powder) as well as the supported ZrO₂ membranes was studied in detail. The molecular weight cut off (MWCO) and mean pore size of mesoporous ZrO₂ membrane were in the range of 19500-62600 and 7.3-13 nm, respectively. The optimized membrane with an average pore size of 7.3 nm showed a MWCO value of 19500 after heat treatment at 450°C. The corrosion resistance of ZrO₂ membrane showed a relative high stability, as proved by the variation of MWCO of PEG after the membrane was treated with HNO₃ and NaOH.