Application of PVDF membranes in desalination and comparison of the VMD and DCMD processes

► Homemade flat-sheet PVDF membranes were used for desalination by DCMD and VMD processes. ► There was little wetting during the long-term desalination test. ► The mass transport in DCMD was due to the combination of Knudsen diffusion and molecular diffusion. ► The combination of Knudsen diffusion, molecular diffusion and Poiseuille flow existed in VMD. ► The homemade membrane was more suitable for use in the VMD process than in the DCMD process.