Electrospun PVDF nanofibrous membranes effectively capturing PM2.5 and releasing negative ions

Abstract

Polyvinylidene fluoride (PVDF) nanofibrous membranes doped with negative ion powder were fabricated by electrospinning, which were aimed to efficiently capture PM2.5 and robustly release negative ions. Different fiber morphologies were formed by regulating the solution concentration. The effect of solution concentration on air filtration property and negative ion release capacity of the PVDF membranes was also investigated. The results show that with the increase of PVDF concentration, bead-on-string fibers are formed firstly and then smooth fibers with larger diameters can be obtained. The filtration efficiency and the pressure drop increase initially and then decrease. The quality factor of the membrane is highest when the PVDF concentration is 17 wt%. The negative ion release amount is small due to the formation of bead-on-string structure at low solution concentration; then it reaches the highest value of 2026 ions/cm3 when the PVDF concentration is 17 wt%. However, further increase of the solution concentration intensity the covering of polymeric components on negative ion powder, therefore, the negative ion release amount reduces gradually.