Abstract:

Fluorite-type Y₂O₃/ZrO₂(YSZ) powders with the mean particle size of 1.74 μm were synthesized by the citric acid combustion method. Using the prepared YSZ powders, gastight hollow fibre membranes were fabricated by a dry-wet spinning process based on the phase inversion technique, followed by sintering at 1 400 ℃ for 4 h. The gas tightness, porosity, mechanical strength, microstructure and crystalline phase of the hollow fibre membranes were studied. The results indicate that the prepared YSZ hollow fibre membranes are gastight while the porosity remains around 23.04% and the bending strength may be up to 322 MPa. The diameter of the pores in the hollow fibres ranges from 60 to 500 nm. XRD spectra show that the fluoritetype phase is kept unchanged, but the crystal size grows bigger after sintering. SEM micrographs show that the prepared YSZ hollow fibre membranes possess an asymmetric structure that includes a dense layer and porous layers, while the inner and outer surfaces are also dense.

Key words: Y₂O₃stabilized ZrO₂(YSZ); Hollow fibre; Inorganic membrane; Asymmetric membrane