Electrospun nanofiber-supported thin-film composite membrane by introducing graphene oxide interlayer for water vapor/N2 separation

In response to the increasing challenge of global water scarcity, the need for alternative water resources has become increasingly critical. Membrane technologies for water vapor separation have emerged as promising approaches for water recovery and reuse. In this study, a polyethersulfone electrospun nanofiber-supported thin-film composite (eTFC) membrane structure with graphene oxide (GO) interlayer, specifically designed for water vapor/N2 separation was introduced. The interlayer was fabricated by controlling the deposition of GO on the electrospun nanofiber substrate. Subsequently, the thin-film was formed through interfacial polymerization using trimesoyl chloride and piperazine as monomers. All the prepared membranes were characterized using analytical techniques. Their water vapor separation performance was evaluated under different water activity conditions and compared to commercial membrane with similar average pore size. The optimized Gi-eTFC (with a GO interlayer of 0.4 mg) exhibited enhanced hydrophilicity, superior water vapor permeance of 3817 GPU, and a relatively high water vapor/N2 selectivity of 115, under conditions of 80 % relative humidity, 1 bar pressure, and a temperature of 30 °C. Gi-eTFC membranes with an optimized GO interlayer showed uniform and successful polyamide active-layer formation, confirming that the introduction of the GO interlayer and the use of nanofibers had a synergistic effect on improving water vapor separation performance. [Display omitted] •Gi-eTFC was developed based on GO-interlayered nanofiber substrate with PA thin film.•Defect-free selective PA layer of Gi-eTFC was stably formed with well-crosslinking.•PA thin film with optimum surface roughness enables improved water vapor permeation.•The highest water vapor permeance (3817 GPU) and selectivity (115) have been achieved.•Integration of the GO-interlayer and nanofiber enables high-performance TFC membrane.