Preparation of porous aluminium oxide (Al2O3) hollow fibre membranes by a combined phase-inversion and sintering method

Al2O3 hollow fibre membranes were prepared by a combined phase-inversion and sintering method. An organic binder solution (dope) containing suspended aluminium oxide (Al2O3) powders, either in mono size or a distributed size, is spun to a hollow fibre precursor, which is then sintered at elevated temperatures. In spinning the hollow fibre precursor, polyethersulfone (PESf), N-methyl-2-pyrrolidone (NMP) and polyvinyl pyrrolidone (PVP) were used as a polymer binder, a solvent and an additive, respectively. The Al2O3 hollow fibre membranes prepared were characterized using a scanning electron microscope (SEM) and gas permeation techniques. Effects of Al2O3 particle size and size distribution, the sintering temperature and Al2O3/PESf ratio on the structure and performance of the resulting membranes were studied extensively. The prepared Al2O3 hollow fibre membranes retains its asymmetric structure (mainly resulted from the phase inversion technique) even after the sintering process. Preparation of the Al2O3 hollow fibre membrane with a high mechanical strength and moderate permeation characteristics is feasible if the Al2O3 powders with a distributed particle size in the spinning (dope) solution is employed.