Plasma-assisted facile fabrication of omniphobic graphene oxide membrane with anti-wetting property for membrane distillation

Novel design of omniphobic membrane could relieve the wetting phenomenon caused by low surface energy contaminants in the feed of membrane distillation process. In this work, we reported on a new kind of omniphobic graphene oxide (GO) membrane fabricated by plasma treatment and subsequent fluoroalkyl grafting of stacked GO laminates. The plasma treatment not only created in-plane nanopores in GO nanosheets to provide more water channels, but also added active sites for fluoroalkyl grafting to build a robust omniphobic membrane surface. The resulting omniphobic membrane exhibited outperformed water flux of ∼35 kg m−2 h−1 and salt rejection of 99.9% for 35 g L−1 NaCl solution with 0.2–0.4 mM sodium dodecyl sulfate (SDS) at 60 °C during over 450 h of direct contact membrane distillation (DCMD) process. This work provides a facile strategy to develop high-flux and wetting-resistance materials for membrane distillation.