Needleless electrospinning for scaled-up production of ultrafine chitosan hybrid nanofibers used for air filtration

Abstract

Large scale ultrafine chitosan hybrid nanofibers containing TiO2 and/or Ag nanoparticles were prepared using needleless electrospinning method. The nanofiber production rate was reached 50 g/h by needleless electrospinning method, which was much higher than 0.02-1 g/h in the traditional single needle electrospinning method. By optimizing the spinning parameters, nanofibers with a smooth uniform morphology were obtained with diameters ranging from 25 to 60 nm and Ag nanoparticles with average size of 2.9 nm were deposited on the surface of the nanofibers without aggregation. The hybrid nanofibers exhibted a significant increase in filtration efficiency (> 99%) for removal of nanoparticles aerosol, comparable to commercial high-efficiency particulate air filters, but with lower pressure drop and less mess. The chitosan hybrid nanofibers showed excellent antibacterial activity, e.g. 97% of E. coli and 99% of S. aureus were killed within 2 h. The cross-linked nanofibers exhibited excellent water durability and maintained a stable microstructure in high humidity and in water immersion. The daily productivity can be achieved above 1.2 kg, which make this ultrafine nanofibers possible in the application of wound dressing, air filtration and environmental purification