Asymmetric porous cordierite hollow fiber membrane for microfiltration

Cordierite hollow fiber membranes have been developed by a combined phase inversion and sintering technique. The spinning suspension was prepared from cordierite powder, polyethersulfone (PES) as polymer binder, N-methyl-2-pyrrolidone (NMP) as solvent and polyvinylpyrrolidone (PVP) as additive. The particle size of cordierite powders has important influence on the microstructure of the prepared hollow fiber membranes. The hollow fiber membranes, derived from cordierite powder with larger particle size (d₅₀ = 7.8 μm), show the asymmetric structure including the inner macro-void structure and the outer thin sponge-like structure. The influences of sintering temperature on the microstructure, porosity, pore size distribution, gas permeability, bending strength and thermal expansion were investigated in detail. Results show that the asymmetric and porous cordierite hollow fiber membrane with a nitrogen permeate flux of 745 m³ m^-2 h^-1 bar^-1, bending strength of 76.5 MPa, and linear thermal expansion coefficient of 2.39 × 10^-6 °C^-1 can be obtained when sintered at 1360 °C for 2 h. This work indicates that the asymmetric cordierite hollow fiber membrane for microfiltration can be prepared by one step, using industrial grade powders with relatively large particle size as raw material.