Preparation and performance of PVDF/PDA blend membranes

Based on the self-polymerization of dopamine,polydopamine(PDA)was synthesized.Through addition of PDA into PVDF casting solutions,PVDF/PDA blend membranes were prepared by L-S phase inversion techniques.The morphologies and hydrophilic properties of such PVDF/PDA membranes were investigated through the methods of SEM,UF experiments,as well as antifouling tests.The effects of the blending ratio and PDA concentration on the antifouling properties of the membranes were also investigated.When the PDA concentration was 0.3%,the flux of the blend membrane was increased from 56.19L/(m2 h)of controlled membrane to 69.63L/(m2 h).In order to test the antifouling performance of the membranes,the two cycle filtration test was carried out.The results showed that the antifouling properties of the blend membranes were enhanced greatly.For the first cycle and second cycle the flux recovery ratio of the PVDF/PDA membranes were both above 90%,compared with 68.5%and 56.4% of the controlled PVDF membranes.