Nanofibrous Facemasks with Curcumin for Improved Bacterial/Particulate Filtration and Biocidal Activity

The current COVID-19 pandemic situation has posed a significant threat to human health. This calls for versatile facemask filters with high filtration efficiency and biocidal activity. Herein, we have rationally designed a three-layered nanofilter mask consisting of electrospun polycaprolactone (PCL) and curcumin as a nanocoating on a polypropylene spunbond membrane. The nanomask thus developed had a particulate filtration efficiency of 96.8 ± 0.1%, with good breathability (64 ± 2 Pa) and a high quality factor (0.052 ± 0.0005 Pa–1) for a coating thickness of ∼20 μm. An aerosol filtration efficiency of >99.99% was achieved for both bacteria and bacteriophages (a virus surrogate). Curcumin loading into the nanocoating induced significant contact-killing efficiency against bacteria and bacteriophages, implying the high biocidal activity presented by the nanomask. Furthermore, this mask could be reused up to 30 times after successive washing and drying, without alterations in its particle-filtration efficiency or fibrous morphology. Thus, by adopting a simple, scalable technique, a nanomask with manifold features was developed that satisfies the essential demands of air filtration in the current pandemic era.