Modified polyvinylidene fluoride ultrafiltration membrane coated with polydopamine/3‐(2,3‐epoxypropoxy) propyl triethoxy silane

Using polyvinylidene fluoride (PVDF) as the membrane material, polyvinylpyrrolidone (PVP) as the additive, and N‐methyl pyrrolidone (NMP) as the solvent, the polyvinylidene fluoride (PVDF) ultrafiltration membrane was prepared by the phase inversion method, and using polydopamine (PDA)/3‐(2,3‐epoxypropoxy) propyl triethoxy silane (KH‐561) to modify the PVDF ultrafiltration membrane, using the rejection rate of bovine serum album (BSA) and pure water flux as indicators to optimize the casting solution formulation. The experimental results show that the best condition is: PVDF of 18 wt%, PVP of 2 wt%, NMP of 80 wt%. The PDA/KH‐561 hybrid coating can be evenly distributed on the surface of the PVDF ultrafiltration membrane, which significantly improves the hydrophilic performance and anti‐pollution performance of the ultrafiltration membrane. The optimal ratio of PDA/KH‐561 is obtained from the experiment results. In the case of the ratio 0.2/0.9, the performance of the membrane is the best, the water flux is 174 L m−2 h−1, the rejection rate of BSA is 91.4%, the contact angle is reduced from 65 to 40°, and the adsorption capacity of BSA protein decreased from 47 to 18 μg cm−2.