Novel composite multilayer face masks for protection against airborne microorganisms

This research focuses on the development of polyurethane (PU)/silica (SiO 2 ) nanofibrous membranes for the filtration of PM2.5 and bacteria, which has been further incorporated in three-layered face mask comprising cotton fabric, nanofibre membrane and polyester fabric. The surface morphology, PM2.5 filtration efficiency and bacterial filtration efficiency of PU/SiO 2 nanofibrous membranes have been investigated to find out applicability of nanofibrous membranes in the filtration application. PU/SiO 2 nanofibrous membranes (0.5%) are found to have a pressure drop of 126 Pa with filtration efficiency of 95.37% and bacterial filtration efficiency of 99.3% against E. coli bacteria strain. Two- and three-layered fabric structures are developed comprising PU/SiO 2 nanofibrous membranes and their contact angle, water vapor transmission rate and air permeability are studied to observe the breathability and waterproof behaviour of the fabric structure. Three- layered PU/SiO 2 nanofibrous membranes have contact angle, water vapor transmission rate and air permeability of 145±1°, 109 g/m 2 /day and 8.56 cm 3 /s/cm 2 respectively.