Abstract: Mullite ultrafiltration (UF) membrane was prepared on α-Al_2O_3 support by sol-gel method and slip casting technology, using Al(NO_3)_3·9H_2O and TEOS as main raw materials, PVA and glycerol as organic additives. The microstructure and properties of the prepared membrane were characterized by XRD, SEM, N2 isothermal absorption technique, permeate flux and molecular weight cut-off (MWCO) measurements. Results show that homogenous, smooth and crack free mullite UF membrane can be obtained after coated for three times using a single phase sol with a concentration of 0.28 mol/L, pH=2.0, 1.5 wt; PVA, 6 wt; glycerol, and sintered at 1200 ℃ for 2 h. The prepared membrane shows narrow pore size distribution and a mean pore size of 8.4nm. The pure water permeate flux and MWCO of the mullite membrane is about 46.8 L·m~(-2)·h~(-1)·(10~5 Pa)~(-1) and 9 kDa, respectively.

Key words: Mullite ultrafiltration (UF) membrane was prepared on α-Al_2O_3 support by sol-gel method and slip casting technology, using Al(NO_3)_3·9H_2O and TEOS as main raw materials, PVA and glycerol as organic additives. The microstructure and properties of the prepared membrane were characterized by XRD, SEM, N2 isothermal absorption technique, permeate flux and molecular weight cut-off (MWCO) measurements. Results show that homogenous, smooth and crack free mullite UF membrane can be obtained after coated for three times using a single phase sol with a concentration of 0.28 mol/L, pH=2.0, 1.5 wt; PVA, 6 wt; glycerol, and sintered at 1200 ℃ for 2 h. The prepared membrane shows narrow pore size distribution and a mean pore size of 8.4nm. The pure water permeate flux and MWCO of the mullite membrane is about 46.8 L·m~(-2)·h~(-1)·(10~5 Pa)~(-1) and 9 kDa, respectively.