Nanofiber membranes by multi-jet electrospinning arranged as arc-array with sheath gas for electrodialysis applications

Multi-jet electrospinning arranged in an arc array with sheath gas has been developed for the high-efficiency production of nanofiber membranes. The arc array constrains the electric field interferences among multiple nozzles and the sheath gas in laminar flow overcomes the electric repulsive force among the jets. The stretching and focusing effect from the sheath gas reduces both the nanofiber diameter and the diameter range, which helps to realize the continuous stable multi-jet electrospinning to fabricate uniform nanofiber membranes. After the treatment of 98% concentrated sulfuric acid for the reactive exchange groups and a hot-pressing process, the membrane is then applicable to electrodialysis applications. Thanks to the net structure, there are many ion transmission passageways within the membrane, leading to the low membrane resistance and high ion transmission efficiency. Experimentally, the increase of membrane thickness results in the decrease of porosity, ion exchange capacity (IEC) and selective permeability and the increase in membrane resistance. The electrodialysis tests show good ion selection performance with a high desalinization ratio of NaCl solution.