Fabrication Of Nanofibrous Membrane Via Multi-jet Electrospinning And Its Electrodialysis Performance

With the advantages of small diameter,high porosity and large specific surface area,electrospun nanofiber has been widely used in various fields,such as energy sensing,filtration adsorption and biomedicine.High efficiency production of uniform nanofibrous membrane is the key to industrial applications of electrospinning technology.In this work,external field control is introduced to design a curved multi-jet spinneret with auxiliary gas,through which uniform nanofibrous membrane is obtained.The ejection behaviors of the multi-jet and the fabrication of nanofibrous membrane are studied.And then,the application of electropinning nanofibrous membrane in electrodialysis is investigated.The electrical field and gas field distribution of the multi-nozzle spinneret is analyzed.The structure of the multi-nozzle spinneret is optimized to increase the uniformity of electrical field and the constraint of the auxiliary gas,which promotes the ejection efficiency of multi-jet electrospinning.Simulation results show that the curved arrangement improve the uniformity of electrical field.The auxiliary gas forms a stable laminar flow below the nozzle,which provides stretching and restraint force on the jets,the velocity of gas is about 150m/s.The simulation model of bead structure is built up to investigate the influence of electrical field focre,viscoelastic stress,charge repulsive force and gas tensile force on the ejection and deposition process of the multi-jet.The multi-jet behaviors are studied experimentally.With the use of auxiliary gas,the ejection velocity of jet is increased,the evaporation of solvent is accelerated,the deposition area of nanofiber is restricted,the difference of deposition areas is reduced,and the uniformity of nanofibrous membrane is improved.When the gas supply pressure increases from OkPa to 50kPa,the critical voltage of jet injection decreases from 6.8kV to 0.9kV,and the average diameter of nanofiber decreases from 282.48nm to 141.18nm.The high efficiency of nanofibrous membrane preaparation with uniform diameter is achieved with the help of auxiliary gas.The electrospun nanofibrous membrane is used as electrodialysis membrane and the basic performances,such as ion exchange capacity,moisture content,porosity,swelling degree and mechanical tensile strength,are evaluated.A small electrodialysis separation system is set up to carry out the separation experiments.The desalinization ratio of NaCl solution during electrodialysis process with electrospinning nanofibrous membrane is 58.15%.Electrospun nanofibrous membrane has shown good seperation performance.In this paper,a new curved electrospinning multi-jet spinneret is designed to investigate the multi-jet ejection behaviors,the feasibility of electrospinning nanofibrous membrane for the electrodialysis water treatment is proved,which is helpful to promote industrial applications of electrospinning.