Preparation and characterization of ultrathin alumina hollow fiber microfiltration membrane

Ultrathin alumina hollow fibers were prepared by a phase inversion and a sintering method. A polysulfone solution containing well-dispersed alumina powders is spun, which is then sintered at elevated temperature. To increase the packing density of alumina powers in the hollow fiber, 1,4-dioxane was added as a nonsolvent in the polymer solution. The pore size and the porosity of the prepared alumina hollow fiber were 0.2 µm and more than 40%, respectively.

The alumina hollow fiber microfiltration membrane was successfully prepared by the phase inversion and the sintering method. The resulting average pore size and porosity of the membrane were 0.2 µm and 40% determined by SEM and mercury porosimeter. Too high sintered temperature resulted in very low porosity. Alumina powder with the sintering additive (MgO) was better than that without the sintering additive. The alumina hollow fiber has a configuration of less than 2 mm of outer diameter and 0.2 mm of thickness.