Durable and comfortable electrospun nanofiber membranes for face mask applications

Airborne contaminants, including particulate matters (PM), pathogens, and gases are presenting serious health challenges. Electrospinning has emerged as a facile technique for synthesizing nanofiber membranes to be used to separate airborne contaminants. Herein, nanofiber membranes were formed from polyvinylidene fluoride (PVDF) by systematic optimization of the electrospinning process to generate highly efficient face masks. A scalable and comfort (low pressure drop) PVDF nanofiber membrane with high filtration efficiency was achieved through controlling operation parameters of electrospinning process, allowing for controlled inter-fiber spacing and fiber density, and enhanced air filtration performance, durability and comfort of wearing. The PVDF nanofiber membranes exhibited smaller fiber diameter and higher mechanical strength as compared with commercial surgical face masks. The PVDF nanofiber membranes also revealed air filtration efficiencies in the range of 95.8 to 99.7 % for the most penetration particle size (MPPS) 300 nm based on basis weight, higher than commercial surgical mask and the respiratory filter media standards. The quality factor (QF) of PVDF nanofiber membranes is double that of the commercial surgical mask. The PVDF membranes also yielded excellent water vapour transmission (WVT), water contact angle up to 138.6˚, thus supporting the designing of durable and washable membranes. This strategy opens opportunities to be used as environmentally friendly reusable face masks for the removal of ultrafine airborne contaminants, including PM, toxic gases, and pathogens.