Reusable Electrospun Nanofibrous Membranes with Antibacterial Activity for Air Filtration

The demand for face masks is increasing exponentially,especiallywhen the coronavirus pandemic and particulate matter (PM) pollutionhave become serious concerns to public health. However, a lot of pressureis caused by the frequent replacement of traditional masks due tothe easy dissipation of electrostatic charge and the accumulationof pathogenic microorganisms. Herein, nanofibrous membranes with efficientinhibition of bacteria, potent air filtration, and reusability performance,consisting of polyacrylonitrile (PAN) nanofibers coated with chitosanquaternary ammonium salt (HACC), were successfully manufactured bysimple impregnation method and coaxial electrospinning, respectively.The bactericidal rate of the nanofibrous membranes to the attachedbacteria was as high as 99.9% due to the excellent bactericidal activityof the quaternary ammonium groups, which could also be proven by themicroscopic appearance of the bacterial cell membrane rupture. Thepermanent dipole charges provided by PAN nanofibers endowed as-preparednanofibrous membranes the capability to stably capture PM even whenthe static electricity disappeared. Moreover, the filtration capacityof nanofibrous membranes could still be close to the initial valueafter a simple washing, which was even unattainable by commercialfilters. These nanofibrous membranes are expected to replace traditionaldisposable filters to achieve long-life and reusability expectations.