The performance of the PVDF-Fe3O4 ultrafiltration membrane and the effect of a parallel magnetic field used during the membrane formation

► The magnetic field used during the formation of membrane controlled the micro-structure of a ultrafiltration membrane. ► A novel ultratrafiltration membrane with “lamellar macrovoids” in the sublayer could be prepared. ► The membrane with“lamellar macrovoids” in the sublayer had good performance. ► The pure water fluxes of some membranes after a compaction-resistance test at 0.40 MPa only had a 20% reduction.