Preparation And Characterization Of Sulfonated Polysulfone / Polyethersulfone Hollow Fiber Blend Ultrafiltration Membrane

Membrane separation technology has gained worldwide attention because of its high separation efficiency, no secondary pollution, low energy consumption Polyether sulfone (PES) as the second largest synthetic material, has the advantages of cheap and easy to get, good chemical stability, good mechanical properties, resistance to microbial erosion, so it causes concern in the field of new membrane materials However, its applications are limited due to strong hydrophily of PES. Sulfonated polysulfone (SPSf) not only has excellent performance than polysulfone (PS) membrane material, and has a strong hydrophily, but the price is relatively expensive. Thus, preparing a new and good performance (good hydrophilic properties, high mechanical strength, relatively high flux and rejection) blend membranes by blending method of the PES and SPSf is necessary.In this paper, PES and SPSf hollow fiber blend ultrafiltration membranes were prepared by dry-wet phase inversion method. It was discussed that there were the effects of different casting solution conditions,mainly includes:sulfonation degree, sulfonated polysulfone concentration, different molecular PEG, PVP, acids and spinning process (dry-spinning process, coagulation bath temperature, spinning solution temperature, core liquid flow, Winding speed) on the properties of hollow fiber membrane. In addition, chemical structure, hydrophily and morphology were investigated by Fourier transform infrared spectroscopy (FTIR), water contact angle measurements and scanning electron microscopy (SEM), respectively. Not only did it analyze the performance of the blend membrane, but also determined the optimum spinning conditions.In this paper, hollow fiber blend ultrafiltration membrane were prepared by wet-dry method, PES and SPSf as a membrane materials, NN-dimethylacetamide (DMAc) as a solvent, lithium (LiCl) chloride anhydrous as hole-agent. The results showed that in 10% sulfonated degree, sulfonated polysulfone concentration 4wt.%, dry-spinning process 8-12cm, coagulation bath temperature 30℃, winding speed 16 m/s, spinning temperature 50℃, core liquid flow 25 ml/min, performances were the best; By discussing the testing conditions (temperature and pressure, etc.), it is proved that with temperature rising, water flux of blending membrane decreases, while rejection ratio almost is stable;The pure water flux increased with the increase of filtration pressure; With the increase of filtering time, all showed a trend of decrease of the pure water flux, and the greater the pressure, the more obvious the trend of decrease.So the most appropriate pressure was 0.10 MPa or 0.20 MPa.By the water contact angle, porosity, pore size distribution test, further,it illustrated the join of sulfonated polysulfone, greatly improved the hydrophilic, increased the porosity, effectively improved the pore density and pore volume; By universal tensile test, it illustrated the blend membrane possesses good mechanical properties.The best performance of pure PES and bleng membranes spun under the same conditions were tested by bovine serum albumin solution (BSA). In this work, flux decline ratio of bovine serum albumin (BSA) is 15.4%, and the flux recovery ratio 21%; The original PES membrane with temperature rise, water flux and rejection ratio significantly decreased; flux attenuation ratio of BSA solution was 43.8%, the recovery ratio was only 10%.