Antifouling Research Of Polyethersulfone Membrane Used In BSA Solution Filtration

SEM and pore size distribution device were used to characterize the polyethersulfone (PES) and sulfonated polyethersulfone (SPES) membrane. The membrane resistance proportion in filtering 1g/L BSA solution was researched according to Darcy-Poiseuille's law. Results showed that PES membrane pore size range was 0.22-0.27μm and the initial pure water flux was 642L/m2 ? hr. The pseudo steady state flux of filtering 1g/L BSA solution is about 30.4-31.9 L/m2 ? hr. SPES membrane pore size range was 5.2-11.1nm. The initial pure water flux was 8.1L/m2 ? hr and the pseudo steady state flux of filtering 1g/L BSA solution was about 3.4-6.9 L/m2 ? hr. When the PES membrane was used to filter BSA solution, resistance caused of the adsorption and pore blocking was principle and account for 91.1% of total membrane resistance. For the SPES membrane the resistance caused of membrane structure itself account for 41.8%, and the blocking resistance 38.3% of the total. After backflush, pure water flux of PES membrane can be restored to 82%, while that of the SPES membrane can be recovered to 494%.On the PES membrane modified by means of two modified,the first modification is: The PES membranes soaked in 0.5% polyphosphazene heptane mixed solution for 72 hours, naturally drying directly after plasma treatment. SEM ,pore size distribution device, Contact angle measurement,total reflection infrared spectroscopy and XPS were used to characterize the modified PES membranes. The membrane resistance proportion in filtering 1g/L BSA solution was researched according to Darcy-Poiseuille's law. Results showed that PES membrane pore size range was 0.22-0.27μm , after filtration, membrane pore size of 0.08 ~ 0.11μm. The initial contact angle of membrane is 41.3°, droplets penetrate into the membrane of the average residence time is about 3.45s. Modified PES membrane protein liquid in the filter after 8-10min to reach a relatively stable equilibrium flux. The pseudo steady state flux of filtering 1g/L BSA solution is about 17.4-23.2 L/m2 ? hr,is 15.8-21.1% of pure water flux. When the modified PES membrane was used to filter BSA solution. Membrane resistance mainly in the adsorption resistance, up to 49.3%, the membrane pore blocking and gel resistance played a minor role, accounting for 29.8% of the resistance. After backflush, pure water flux of modified PES membrane can be restored to 78.2%. The second modification of PES membrane is used: the PES membranes soaked in 0.5% polyphosphazene heptane mixed solution for 72 hours, the natural drying, and then immediately after plasma treatment soaked in sodium dichloro-ethoxyethanol drying the mixed solution of heptane for 72 hours, after washing with heptane stand. SEM,pore size distribution device, contact angle measurement,total reflection infrared spectroscopy and XPS were used to characterize the modified PES membranes. The membrane resistance proportion in filtering 1g/L BSA solution was researched according to Darcy-Poiseuille's law. Results showed that PES membrane pore size range was 0.20-0.30μm , after filtration, membrane pore size of 0.12 ~ 0.16μm. The initial contact angle of membrane is 41.7°, droplets penetrate into the membrane of the average residence time is about 2.4s. Modified PES membrane protein liquid in the filter after 1.25-2min to reach a relatively stable equilibrium flux. The pseudo steady state flux of filtering 1g/L BSA solution is about 255.1-440.6 L/m2 ? hr,is 45.0-77.7% of pure water flux. For the membrane the resistance caused of membrane structure itself account for 57.9%, adsorption resistance played a minor role,accounting for 26.8%.After backflush, pure water flux of modified PES membrane can be restored to 154.9%.