Porous structure and air filtration performance of electrospun PLA fibers

PLA fibers with nanoporous structures both inside and on the surfaces 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 were studied.The results show that PLA mass fractions and weight ratios of the mixed solvent DCM /DMAC affect significantly,and voltage takes the second place while the flow rate have weak influence.The porous PLA fibrous membrane with high efficiency and low resistance for air filtration was prepared under conditions of PLA mass fractions of 7%,DCM /DMAC ratio 10∶ 1,voltage 16 kV and flow rate 1 mL /h,and the filtration efficiency could reach99.964% when tested by using NaCl aerosol with 75 nm volume median diameter and the pressure drop was just about 197.9 Pa.