Fabrication of a high hydrophobic PVDF membrane via nonsolvent induced phase separation

The aim of this paper is to prepare a PVDF (polyvinylidene fluoride) microporous membrane by using alcohol as nonsolvent (coagulant). A porous membrane with high hydrophobic surface (water contact angle ~148°) was facilely created by wet immersion method without modification with special low surface energy compounds and the need of special instruments. In addition, the PVDF casting film was passed through alcohol bath for 2 s and then immersed into water precipitation bath, the porous PVDF membrane with hydrophobic surface (water contact angle ~135°) was also formed. The characterization of the porous PVDF membrane obtained from various coagulation conditions was carried out by a pore size analysis and a direct contact membrane distillation (DCMD). The permeation flux and rejection coefficient of the porous PVDF membrane fabricated via dual-bath coagulated was close to commercial one.