Reusable Electrospun Nanofibrous Membranes with Antibacterial Activity for Air Filtration

The demand for face masks is increasing exponentially, especially when the coronavirus pandemic and particulate matter (PM) pollution have become serious concerns to public health. However, a lot of pressure is caused by the frequent replacement of traditional masks due to the easy dissipation of electrostatic charge and the accumulation of pathogenic microorganisms. Herein, nanofibrous membranes with efficient inhibition of bacteria, potent air filtration, and reusability performance, consisting of polyacrylonitrile (PAN) nanofibers coated with chitosan quaternary ammonium salt (HACC), were successfully manufactured by simple impregnation method and coaxial electrospinning, respectively. The bactericidal rate of the nanofibrous membranes to the attached bacteria was as high as 99.9% due to the excellent bactericidal activity of the quaternary ammonium groups, which could also be proven by the microscopic appearance of the bacterial cell membrane rupture. The permanent dipole charges provided by PAN nanofibers endowed as-prepared nanofibrous membranes the capability to stably capture PM even when the static electricity disappeared. Moreover, the filtration capacity of nanofibrous membranes could still be close to the initial value after a simple washing, which was even unattainable by commercial filters. These nanofibrous membranes are expected to replace traditional disposable filters to achieve long-life and reusability expectations.