Flexible isoporous air filters for high-efficiency particle capture

Abstract

Air pollution with a high concentration level of particulate matter (PM) holds responsibility for an increasing number of fatalities worldwide. Inhalable and harmful airborne PM, generated by anthropogenic and natural sources, can act as carcinogenic agents and can also absorb and transfer with them viruses and bacteria. Stationary and automove filters, masks are part of our routine life. However, traditional fibrous air filters and improved high-efficiency particulate air filters (HEPA) suffer from several inevitable drawbacks, justifying the search for better alternatives. Herein, we present nanofabricated isoporous polymeric membranes with of PM2.5 and PM10 capture efficiency as high as 99.9%. The membranes were transparent and flexible with pore sizes of 0.7, 2 and 5 µm. Those with 2 µm had a density of 4.13 × 106 pores per cm2. Moreover, membranes coated with silver nanoparticles showed excellent biocidal effect against Acinetobacter baylyi bacteria. The membrane can be used in the heating, ventilation and air conditioning systems of buildings and car cabins, and can be incorporated in personal masking.