Abstract: PLA fibers with nanoporous structures both inside and on the surfaces of them were fabricated via electrospinning. The effect of electrospinning parameters such as PLA mass fractions, weight ratios of the mixed solvent dichloromethane(DCM)/N,N-Dimethylacetamida(DMAC), voltage and flow rate on the pore coverage rate and the pore size on the surface of the fibers have been studied. The results show that PLA mass fractions and weight ratios of the mixed solvent DCM/DMAC affect mostly, voltage take the second place while the flow rate have weak influence. The porous PLA fibrous membrane which was prepared with PLA mass fractions of 7 wt%, DCM/DMAC 10:1, voltage 16kV and flow rate 1mL/h had high efficiency and low resistance for air filtration, the filtration efficiency could reach 99.964% when tested by using NaCl aerosol with 75nm volume median diameter and the pressure drop was just about 197.9Pa.

Key words: electrospinning, porous fiber, PLA, air filtration materials