Composite Membranes with Nanofibrous Cross-Hatched Supports for Reverse Osmosis Desalination

A novel membrane structure composed of cross-hatched electrospun nanofibers is developed. We illustrate that this novel structure allows for much higher water permeability when used as a support for reverse osmosis thin-film composite membranes. Reinforcement and lamination of the aligned nanofibers generates mechanically robust structures that retain very high porosity and low tortuosity when applied to high pressure desalination operations. The cross-hatched nanofiber layers support the polyamide active layer firmly and reduce resistance to water flow due to the high porosity, low tortuosity, high mechanical strength, and minimal thickness of the structures. The nanofiber composite membrane gives a water flux significantly greater than when a traditional support layer is used, at 99 ± 5 m^-2 h^-1 with NaCl rejection of 98.7% at 15.5 bar.