LAUSR

TiO2-ZrO2 colloidal and polymeric sols were successfully prepared using the sol-gel method. The effects of aging and Ti/Zr molar ratios on TiO2-ZrO2 sols and powders were investigated. The particle size of colloidal sols was decreased with an increase in aging time, while the particle size of the polymeric sols increased. TiO2-ZrO2 polymeric sols with Ti/Zr molar ratios that varied from 10/0 to 0/10 showed an increase particle size with an increase in the Zr-content. In addition, TiO2-ZrO2 powders derived from colloidal sols had a crystalline structure even without firing. With firing at temperatures that approached 500 °C, however, TiO2-ZrO2 powders derived from polymeric sols had a structure that was more amorphous than that of pure TiO2 and ZrO2 powders, but the most amorphous structure was achieved at a Ti/Zr molar ratio of 5/5. TiO2-ZrO2 nanofiltration (NF) membranes, which were prepared by coating colloidal and polymeric sols onto α-Al2O3 porous supports, showed an average pore size and molecular weight cut-offs (MWCOs) in the NF range. Average pore size, N2 permeance, water permeability (Lp), and MWCOs of the membranes were generally decreased with an increase in ZrO2 content with an optimum addition of ZrO2 that approached an equimolar composition. TiO2-ZrO2 (9/1, 7/3, 5/5) membranes showed a relatively low MWCO and a moderate Lp, which suggested that these membranes would be good for nanofiltration. TiO2-ZrO2 sols with different Ti/Zr molar ratios were prepared via the sol-gel method. Aging time and temperature affected the sol size of TiO2-ZrO2 sols. Ti/Zr molar ratios affected the structure and separation performance of TiO2-ZrO2 membranes. The most amorphous structure was achieved with a Ti/Zr molar ratio of 5/5. TiO2 -ZrO2 membranes with Ti/Zr molar ratios of 9/1, 7/3, and 5/5 were good for nanofiltration. TiO2-ZrO2 sols with different Ti/Zr molar ratios were prepared via the sol-gel method. Aging time and temperature affected the sol size of TiO2-ZrO2 sols. Ti/Zr molar ratios affected the structure and separation performance of TiO2-ZrO2 membranes. The most amorphous structure was achieved with a Ti/Zr molar ratio of 5/5. TiO2 -ZrO2 membranes with Ti/Zr molar ratios of 9/1, 7/3, and 5/5 were good for nanofiltration.