Synthesis of novel graphene oxide-polyimide hollow fiber membranes for seawater desalination

Hollow fiber membranes are more favorable for the fabrication of membrane modules in industry because of its high membrane area to module volume ratios. In the present work, we reported the preparation of novel graphene oxide (GO)/polyimide (PI) hollow fiber membranes for the first time by direct spinning of a GO/PI suspension via a coaxial two-capillary spinning strategy. The structure and morphology of GO/PI hollow fiber membrane was characterized by using XRD, FT-IR and FESEM. The GO nanosheets can homogeneously be dispersed in the PI matrix to form continuous and robust membranes due to a good compatibility between GO and PI, and GO/PI hollow fiber membrane shows a typical asymmetric structure. The performances of the GO/PI hollow fiber membrane were evaluated for desalination of seawater by pervaporation. The GO/PI hollow fiber membrane displays excellent water permeability and salt rejection for desalination of different concentrations of seawater. At 90 °C, a high water flux (15.6 kg m⁻² h⁻¹) and a high salt rejection (99.8%) can be obtained. Further, the GO/PI hollow fiber membrane displays a high stability for seawater desalination with a long time measurement.