Electrospun polyacrylonitrile nanofiber membranes for air filtration application

Polyacrylonitrile (PAN) nanofiber membranes of varied thicknesses (20–100 µm) were electrospun at a polymer concentration of 14% (w/v) in N,N-Dimethylformamide (DMF); characterized for porosity, pressure drop, air permeability and particle filtration efficiency (PFE). Densities of membranes are found very less (0.11 to 0.21 g/cm3), with porosities in the range of 80–92%, higher porosity was for higher thickness. Membranes were used to measure air pressure drop, which was higher for thicker membranes due to the torturous path encountered by air. Air permeability of membranes decreased with increasing thickness for the same reason. The PFE was higher for thin samples due to less porosity and was lower for thicker samples due to higher porosities and cushion effect. The 20-µm-thick membranes achieved highest PFE of > 99.7% for clearing 0.3 µm particles. Above experiments suggested that PAN nanofiber membranes prepared in this study could be used for face mask in addition to non-woven fabrics.