In-situ polarized coaxial PVDF/PL nanofiber filtration membrane with high efficiency, low resistance and antimicrobial properties

Abstract

Aerosols are prone to breed bacteria on air filtration materials so as to cause secondary air pollution, especially carrying bacteria and viruses. This paper utilized coaxial electrospinning technology with traditional Chinese medicine Physalis alkekengi Linn as the core layer antibacterial material and polyvinylidene fluoride/polyacrylonitrile mixed solution as the shell layer material. Nonsolvent phase separation technology was employed to prepare the porous shell layer, achieving sustained slow-release and long-lasting antibacterial effects from the core P. alkekengi Linn. In addition, an in-situ polarization technology from high voltage in electrospinning process was adopted to achieve permanent polarization of polyvinylidene fluoride, which changed from α-crystal to β-crystal. Using the electrostatic charge adsorption effect and the ultra-fine pore size screening of the nanofiber membrane, high-efficiency and low-resistance filtration of aerosols above 0.3 μm was achieved (99.98% filtration efficiency and filtration resistance less than 25 Pa). It can be widely used in the field of air filtration and protection in high-risk environments such as stations, schools, and hospitals, achieving long-lasting antibacterial, high-efficiency, and low-resistance air filtration and protection.