Versatile nanofibrous filters against fine particulates and bioaerosols containing tuberculosis and virus: Multifunctions and scalable processing

Abstract

• Novel nanofibrous membrane was simply made from mangosteen and Ag-PAN/PVDF. • Nanofilter is antimicrobial against gram +/− bacteria, tuberculosis and H1N1 virus. • Nanofilter is stable against severe weathering suitable for versatile filtration uses. • Breathable nanomasks show high filtering efficiency (PFE 94%, BFE 99%, VFE 98%). Herein, versatile, mechanically robust, and highly-scalable electrospun nanofibrous composite filters towards unprecedented potent antimicrobial and excellent filtering properties are successfully designed and fabricated. Experimentally, the nanofibrous polyacrylonitrile (PAN) blended with polyvinylidene fluoride (PVDF) is fabricated for the dual quality of both PAN’s filtering capability and PVDF’s hydrophobic nature. Achieved without toxic polymer crosslinking agents or high-temperature post-treatment curing/annealing, the nanomembrane shows high water repellency, high mechanical/thermal stabilities and good spinnability. The PAN/PVDF membranes loaded with natural extract mangosteen ( Garcinia mangostana L., GM) and a minimum amount of in situ synthesized silver nanoparticles are first developed by needle-based electrospinning and, later, by a scalable blown electrospinning system, which applied an air-assisted technique to enhance the production rate. Our respective face masks show not only high filtering efficiency towards fine particulate matters (PMs) (93.91% for 0.5 µm) and bioaerosols (bacterial filtration efficiency (BFE) of 99.2% and viral filtration efficiency (VFE) of 98.3%), but also antimicrobial abilities against gram-positive Staphylococcus aureus , gram-negative Klebsiella pneumonia , Mycobacterium smegmatis and Mycobacterium tuberculosis H37Ra bacteria. Moreover, by virus inhibition assay and rRT-PCR, the nanomembrane shows a 99.94% reduction of H1N1 influenza virus. Despite this unprecedented novel multifunctionality, it is easier to breathe than commercial face masks with similar particle filtering performance. The stability of the membrane against severe simulated weathering (ASTM G154:2006) was confirmed for potential use as filters in air conditioning or outdoor space.