Radiative cooling face mask based on mixed micro- and nanofibrous fabric

A type of personal protective face mask with thermal comfort function is developed based on the radiative cooling concept. We show that the cooling face mask, with the combination of PLA meltblown microfibers and a thin sheet of mixed electrospun micro- and nanofibers as filtration media and a silk fabric as inner supporting layer, can provide high reflectivity (>85 %) in the solar spectrum and high emissivity (>96 %) in the atmospheric window. Outdoor measurement of simulated skin temperature demonstrates the skin covered by our cooling mask could be similar to 2.7degree celsius lower than that covered by commercial 3 M N95 mask. Our cooling mask exhibits excellent filtration performance with 99.98 % filtration efficiency and < 110 Pa pressure drop because of the reduced stacking density of the filtration media. This research has the potential of developing thermal management textiles.