One-step fabricated bionic PVDF ultrafiltration membranes exhibiting innovative antifouling ability to the cake fouling

In view of the excellent application properties of the bionic materials, a novel polyvinylidene fluoride (PVDF) ultrafiltration membrane with regular nanoscale papillae on the membrane surface imitating the mosquito eye structures was fabricated by one-step molding method. The amphiphilic wetting agent (EW-326) was used in the membrane preparation process for the generation of numerous papillae with the diameter of 200–300   nm by adjusting the phase separation process during the membrane formation. The test results of filtration fouling showed that the bionic PVDF membrane exhibited different fouling resistances between the adhesive pollutants (e.g. bovine serum albumin, BSA) and the cake layer pollutants (e.g. sodium alginate , SA) due to the different fouling layers formed on top of the papillae structure. The water flux recovery ratio (FRR) value of bionic PVDF membrane was still higher than 90% even after three fouling cycles with the SA pollutant solution. Meanwhile, this novel modified PVDF membrane also exhibited expected antifouling performance to the sewage. The novel preparation method of bionic membrane exhibits a significant effect for enhancing the antifouling performance of ultrafiltration process with cake layer formed, and can provide new insight into the formation of separation membranes with regulated surface structure.