Mass production of nanofibers from needleless electrospinning by a novel annular spinneret

A novel annular spinneret was developed for the needleless mass production of nanofibers. Polymer solution was transported to the top of the annular where multiple jets were formed when the applied voltage exceeded a certain value. Electric field intensity values were simulated by finite element software. Morphology, diameter and productivity of nanofibers were investigated by changing the electrospinning process parameters which were solution concentration, applied voltage, collection distance and solution flow rate. The results showed the highest electric field strength value at the top of annular spinneret. The diameter of nanofibers gradually increased with the solution concentration. Increasing the applied voltage, collection distance and solution flow rate had some significant influence on the diameter of nanofibers. The highest productivity of nanofibers reached 4.5 g/h. Filtration properties and pore diameter distribution of the nanofibers membranes were investigated and these exhibited potential for air filtration. It was noteworthy that this method maximally utilized the solution to form multiple jets, since it significantly reduced the effect of solvent evaporation in the electrospinning process. Annular spinneret offered a potential for large scale production of nanofibers in the future.