Unleashing the potential of scalable, high-water vapor permeance graphene oxide membranes using electrospun supports

Dehumidification and dehydration technologies are projected to consume a substantial portion of the world's energy demand through the HVAC, and chemical processing industries. The development of highly permeable water-selective membranes represents a potential path to revolutionize these industries by drastically reducing their energy requirements. Selective layers based on graphene oxide (GO) have demonstrated the highest water vapor permeances to date, making GO a promising candidate for reducing the footprint and costs associated with commercial module development. However, most studies primarily focus on small-area membranes fabricated utilizing vacuum or pressure filtration, leading to either thick free-standing films or thin layers supported on model substrates such as anodic aluminium oxide. In this work, a casting approach is deployed to coat thin GO layers onto large-area membrane supports. In addition to the application of scalable methods, commonly used supports act as a significant bottleneck to the overall permeance. By designing highly porous (up to 92%) electrospun polystyrene supports, we demonstrate a 27% increase in overall permeance as compared to commercial Nylon and polyethersulfone supports even though these membranes have thicker GO selective layers. Despite the pore size in the electrospun material being larger than the GO flakes, the GO forms a selective layer via casting, and achieved water to nitrogen selectivity larger than 10³.