A preliminary study on the preparation condition of hollow fiber membranes using thermally induced phase separation method

Abstract

In this study, thermally induced phase separation (TIPS)methodwas usedtofabricate hollow fiber membranes from the dope solution of polyethersunfone (PES) in dimethylformamide (DMF) solvent. The effect of PES concentrations (in the range of 15-22%) on mechanical properties and filterability of the PES membranes was investigated. Results showed that the viscosity of the dope solution increased from 119 mPa.s to 1,300 mPa.s when increasing the PES concentration. The tensile strength of manufactured membranes tended to increase (from 3.63 MPa to 5.56 MPa) as the viscosity of the dope solution increased. Meanwhile, the specific flux of fabricated membranes tended to decrease as the PES concentration increased. The the specific flux of membranes fabricated with the PES concentration of 15% was 82.74 l/m2 .h.bar, but the membrane seemed to have no filterability when the PES concentration was increased to 22%. Results also indicated that the usage of pore forming additive (3-10% of polyvinylpyrrolidone) led to higher water fluxes. With an additive content of 10%, the specific flux of the PES membranes increased five times compared with the case without any additive.